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Wang X, Carvajal-Moreno J, Zhao X, Li J, Hernandez VA, Yalowich JC, Elton TS. Circumvention of Topoisomerase II α Intron 19 Intronic Polyadenylation in Acquired Etoposide-Resistant Human Leukemia K562 Cells. Mol Pharmacol 2024; 106:33-46. [PMID: 38719474 PMCID: PMC11187689 DOI: 10.1124/molpharm.124.000868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 04/12/2024] [Indexed: 06/20/2024] Open
Abstract
DNA topoisomerase IIα (TOP2α; 170 kDa, TOP2α/170) is an essential enzyme for proper chromosome dysjunction by producing transient DNA double-stranded breaks and is an important target for DNA damage-stabilizing anticancer agents, such as etoposide. Therapeutic effects of TOP2α poisons can be limited due to acquired drug resistance. We previously demonstrated decreased TOP2α/170 levels in an etoposide-resistant human leukemia K562 subline, designated K/VP.5, accompanied by increased expression of a C-terminal truncated TOP2α isoform (90 kDa; TOP2α/90), which heterodimerized with TOP2α/170 and was a determinant of resistance by exhibiting dominant-negative effects against etoposide activity. Based on 3'-rapid amplification of cDNA ends, we confirmed TOP2α/90 as the translation product of a TOP2α mRNA in which a cryptic polyadenylation site (PAS) harbored in intron 19 (I19) was used. In this report, we investigated whether the resultant intronic polyadenylation (IPA) would be attenuated by blocking or mutating the I19 PAS, thereby circumventing acquired drug resistance. An antisense morpholino oligonucleotide was used to hybridize/block the PAS in TOP2α pre-mRNA in K/VP.5 cells, resulting in decreased TOP2α/90 mRNA/protein levels in K/VP.5 cells and partially circumventing drug resistance. Subsequently, CRISPR/CRISPR-associated protein 9 with homology-directed repair was used to mutate the cryptic I19 PAS (AATAAA→ACCCAA) to prevent IPA. Gene-edited clones exhibited increased TOP2α/170 and decreased TOP2α/90 mRNA/protein and demonstrated restored sensitivity to etoposide and other TOP2α-targeted drugs. Together, results indicated that blocking/mutating a cryptic I19 PAS in K/VP.5 cells reduced IPA and restored sensitivity to TOP2α-targeting drugs. SIGNIFICANCE STATEMENT: The results presented in this study indicate that CRISPR/CRISPR-associated protein 9 gene editing of a cryptic polyadenylation site (PAS) within I19 of the TOP2α gene results in the reversal of acquired resistance to etoposide and other TOP2-targeted drugs. An antisense morpholino oligonucleotide targeting the PAS also partially circumvented resistance.
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Affiliation(s)
- Xinyi Wang
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Jessika Carvajal-Moreno
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Xinyu Zhao
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Junan Li
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Victor A Hernandez
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Jack C Yalowich
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
| | - Terry S Elton
- Division of Pharmaceutics and Pharmacology, College of Pharmacy (X.W., J.C.-M., X.Z., V.A.H., J.C.Y., T.S.E.) and Division of Outcomes and Translational Science (J.L.), The Ohio State University, Columbus, Ohio
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Elton TS, Hernandez VA, Carvajal-Moreno J, Wang X, Ipinmoroti D, Yalowich JC. Intronic Polyadenylation in Acquired Cancer Drug Resistance Circumvented by Utilizing CRISPR/Cas9 with Homology-Directed Repair: The Tale of Human DNA Topoisomerase IIα. Cancers (Basel) 2022; 14:cancers14133148. [PMID: 35804920 PMCID: PMC9265003 DOI: 10.3390/cancers14133148] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 12/02/2022] Open
Abstract
Simple Summary DNA topoisomerase IIα (170 kDa, TOP2α/170) resolves nucleic acid topological entanglements by generating transient double-strand DNA breaks. TOP2α inhibitors/poisons stabilize TOP2α-DNA covalent complexes resulting in persistent DNA damage and are frequently utilized to treat a variety of cancers. Acquired resistance to these chemotherapeutic agents is often associated with decreased TOP2α/170 expression levels. Studies have demonstrated that a reduction in TOP2α/170 results from a type of alternative polyadenylation designated intronic polyadenylation (IPA). As a consequence of IPA, variant TOP2α mRNA transcripts have been characterized that have resulted in the translation of C-terminal truncated TOP2α isoforms with altered biological activities. In this paper, an example is discussed where circumvention of acquired TOP2α-mediated drug resistance was achieved by utilizing CRISPR/Cas9 specific gene editing of an exon/intron boundary through homology directed repair (HDR) to reduce TOP2α IPA. These results illustrate the therapeutic potential of CRISPR/Cas9/HDR to impact drug resistance associated with aberrant IPA. Abstract Intronic polyadenylation (IPA) plays a critical role in malignant transformation, development, progression, and cancer chemoresistance by contributing to transcriptome/proteome alterations. DNA topoisomerase IIα (170 kDa, TOP2α/170) is an established clinical target for anticancer agents whose efficacy is compromised by drug resistance often associated with a reduction of nuclear TOP2α/170 levels. In leukemia cell lines with acquired resistance to TOP2α-targeted drugs and reduced TOP2α/170 expression, variant TOP2α mRNA transcripts have been reported due to IPA that resulted in the translation of C-terminal truncated isoforms with altered nuclear-cytoplasmic distribution or heterodimerization with wild-type TOP2α/170. This review provides an overview of the various mechanisms regulating pre-mRNA processing and alternative polyadenylation, as well as the utilization of CRISPR/Cas9 specific gene editing through homology directed repair (HDR) to decrease IPA when splice sites are intrinsically weak or potentially mutated. The specific case of TOP2α exon 19/intron 19 splice site editing is discussed in etoposide-resistant human leukemia K562 cells as a tractable strategy to circumvent acquired TOP2α-mediated drug resistance. This example supports the importance of aberrant IPA in acquired drug resistance to TOP2α-targeted drugs. In addition, these results demonstrate the therapeutic potential of CRISPR/Cas9/HDR to impact drug resistance associated with aberrant splicing/polyadenylation.
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Hernandez VA, Carvajal-Moreno J, Wang X, Pietrzak M, Yalowich JC, Elton TS. Use of CRISPR/Cas9 with homology-directed repair to silence the human topoisomerase IIα intron-19 5’ splice site: Generation of etoposide resistance in human leukemia K562 cells. PLoS One 2022; 17:e0265794. [PMID: 35617303 PMCID: PMC9135202 DOI: 10.1371/journal.pone.0265794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/06/2022] [Indexed: 11/19/2022] Open
Abstract
DNA Topoisomerase IIα (TOP2α/170) is an enzyme essential for proliferating cells. For rapidly multiplying malignancies, this has made TOP2α/170 an important target for etoposide and other clinically active anticancer drugs. Efficacy of these agents is often limited by chemoresistance related to alterations in TOP2α/170 expression levels. Our laboratory recently demonstrated reduced levels of TOP2α/170 and overexpression of a C-terminal truncated 90-kDa isoform, TOP2α/90, due to intronic polyadenylation (IPA; within intron 19) in an acquired etoposide-resistant K562 clonal cell line, K/VP.5. We previously reported that this isoform heterodimerized with TOP2α/170 and was a determinant of acquired resistance to etoposide. Optimization of the weak TOP2α exon 19/intron 19 5′ splice site in drug-resistant K/VP.5 cells by gene-editing restored TOP2α/170 levels, diminished TOP2α/90 expression, and circumvented drug resistance. Conversely, in the present study, silencing of the exon 19/intron 19 5′ splice site in parental K562 cells by CRISPR/Cas9 with homology-directed repair (HDR), and thereby forcing intron 19 retention, was used to induce resistance by disrupting normal RNA processing (i.e., gene knockout), and to further evaluate the role of TOP2α/170 and TOP2α/90 isoforms as resistance determinants. Gene-edited clones were identified by quantitative polymerase chain reaction (qPCR) and verified by Sanger sequencing. TOP2α/170 mRNA/protein expression levels were attenuated in the TOP2α gene-edited clones which resulted in resistance to etoposide as assessed by reduced etoposide-induced DNA damage (γH2AX, Comet assays) and growth inhibition. RNA-seq and qPCR studies suggested that intron 19 retention leads to decreased TOP2α/170 expression by degradation of the TOP2α edited mRNA transcripts. Forced expression of TOP2α/90 in the gene-edited K562 cells further decreased etoposide-induced DNA damage in support of a dominant negative role for this truncated isoform. Together results support the important role of both TOP2α/170 and TOP2α/90 as determinants of sensitivity/resistance to TOP2α-targeting agents.
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Affiliation(s)
- Victor A. Hernandez
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
| | - Jessika Carvajal-Moreno
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
| | - Xinyi Wang
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
| | - Maciej Pietrzak
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Jack C. Yalowich
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (JCY); (TSE)
| | - Terry S. Elton
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (JCY); (TSE)
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Gantner BN, LaFond KM, Bonini MG. Nitric oxide in cellular adaptation and disease. Redox Biol 2020; 34:101550. [PMID: 32438317 PMCID: PMC7235643 DOI: 10.1016/j.redox.2020.101550] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 02/07/2023] Open
Abstract
Nitric oxide synthases are the major sources of nitric oxide, a critical signaling molecule involved in a wide range of cellular and physiological processes. These enzymes comprise a family of genes that are highly conserved across all eukaryotes. The three family members found in mammals are important for inter- and intra-cellular signaling in tissues that include the nervous system, the vasculature, the gut, skeletal muscle, and the immune system, among others. We summarize major advances in the understanding of biochemical and tissue-specific roles of nitric oxide synthases, with a focus on how these mechanisms enable tissue adaptation and health or dysfunction and disease. We highlight the unique mechanisms and processes of neuronal nitric oxide synthase, or NOS1. This was the first of these enzymes discovered in mammals, and yet much remains to be understood about this highly conserved and complex gene. We provide examples of two areas that will likely be of increasing importance in nitric oxide biology. These include the mechanisms by which these critical enzymes promote adaptation or disease by 1) coordinating communication by diverse cell types within a tissue and 2) directing cellular differentiation/activation decisions processes.
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Affiliation(s)
- Benjamin N Gantner
- Department of Medicine, Division of Endocrinology, Medical College of Wisconsin, USA.
| | - Katy M LaFond
- Department of Medicine, Division of Endocrinology, Medical College of Wisconsin, USA
| | - Marcelo G Bonini
- Department of Medicine, Division of Endocrinology, Medical College of Wisconsin, USA; Feinberg School of Medicine, Division of Hematology and Oncology, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, USA
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5
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Bansal P, Arora M. RNA Binding Proteins and Non-coding RNA's in Cardiovascular Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1229:105-118. [PMID: 32285407 DOI: 10.1007/978-981-15-1671-9_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cardiovascular disease (CVD) is the leading cause of mortality as well as morbidity worldwide. The disease has been reported to be chronic in nature and the symptoms of the disease worsen progressively over a long period of time. Inspite of noteworthy achievements have been made in the therapy of CVD yet the available drugs are associated with various undesirable factors including drug toxicity, complexity, resistance and many more. The versatility of RNAs makes them crucial therapeutics candidate for many human diseases. Deeper understanding of RNA biology, exploring new classes of RNA that possess therapeutic potential will help in its successful translation to the clinic. Understanding the mode of action of various RNAs such as miRNA, RNA binding proteins and siRNA in CVD will help in improved therapeutics among patients. Multiple strategies are being planned to determine the future potential of miRNAs to treat a disease. This review embodies the recent work done in the field of miRNA and its role in cardiovascular disease as diagnostic biomarker as well as therapeutic agents. In addition the review highlights the future of miRNAs as a potential therapeutic target and need of designing micronome that may reveal potential predictive targets of miRNA-mRNA interaction.
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Affiliation(s)
- Parveen Bansal
- University Centre of Excellence in Research, Baba Farid University of Health Sciences, Faridkot, Punjab, India.
| | - Malika Arora
- Multidisciplinary Research Unit, Guru Gobind Singh Medical College, Faridkot, Punjab, India
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Camacho-Mejorado R, Gómez R, Torres-Sánchez LE, Alhelí Hernández-Tobías E, Noris G, Santana C, Magaña JJ, Orozco L, de la Peña-Díaz A, de la Luz Arenas-Sordo M, Meraz-Ríos MA, Majluf-Cruz A. ALOX5, LPA, MMP9 and TPO gene polymorphisms increase atherothrombosis susceptibility in middle-aged Mexicans. ROYAL SOCIETY OPEN SCIENCE 2020; 7:190775. [PMID: 32218930 PMCID: PMC7029922 DOI: 10.1098/rsos.190775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
Atherothrombosis is the cornerstone of cardiovascular diseases and the primary cause of death worldwide. Genetic contribution to disturbances in lipid metabolism, coagulation, inflammation and oxidative stress increase the susceptibility to its development and progression. Given its multifactorial nature, the multiloci studies have been proposed as potential predictors of susceptibility. A cross-sectional study was conducted to explore the contribution of nine genes involved in oxidative stress, inflammatory and thrombotic processes in 204 subjects with atherothrombosis matched by age and gender with a healthy group (n = 204). To evaluate the possibility of spurious associations owing to the Mexican population genetic heterogeneity as well as its ancestral origins, 300 unrelated mestizo individuals and 329 Native Americans were also included. ALOX5, LPA, MMP9 and TPO gene polymorphisms, as well as their multiallelic combinations, were twice to four times more frequent in those individuals with clinical manifestations of atherothrombosis than in the healthy group. Once adjusting for population stratification was done, these differences remained. Our results add further evidence on the contribution of ALOX5, LPA, MMP9 and TPO polymorphisms to atherothrombosis development in the middle-aged group, emphasizing the multiethnic studies in search of gene risk polymorphisms.
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Affiliation(s)
| | - Rocío Gómez
- Departamento de Toxicología, Cinvestav-IPN, Mexico City 07360, Mexico
| | - Luisa E. Torres-Sánchez
- Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
| | | | - Gino Noris
- Laboratorio Biología Molecular Diagnóstica, Querétaro, Qro, Mexico
| | - Carla Santana
- Laboratorio Biología Molecular Diagnóstica, Querétaro, Qro, Mexico
| | | | - Lorena Orozco
- Laboratorio de Inmunogenómica y Enfermedades Metabólicas, INMEGEN, Mexico City, Mexico
| | - Aurora de la Peña-Díaz
- Facultad de Medicina, Departamento de Farmacología, Universidad Nacional Autónoma de México, Mexico
- Departamento de Biología Molecular, Instituto Nacional de Cardiología, Mexico City, Mexico
| | | | | | - Abraham Majluf-Cruz
- Unidad de Investigación Médica en Trombosis, Hemostasia y Aterogénesis, IMSS, Mexico City, Mexico
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7
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Gresele P, Momi S, Guglielmini G. Nitric oxide-enhancing or -releasing agents as antithrombotic drugs. Biochem Pharmacol 2019; 166:300-312. [DOI: 10.1016/j.bcp.2019.05.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 05/31/2019] [Indexed: 12/16/2022]
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8
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High Concentration of Low-Density Lipoprotein Results in Disturbances in Mitochondrial Transcription and Functionality in Endothelial Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7976382. [PMID: 31281593 PMCID: PMC6590621 DOI: 10.1155/2019/7976382] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/30/2019] [Accepted: 05/14/2019] [Indexed: 12/13/2022]
Abstract
Concentrations of low-density lipoprotein (LDL) above 0.8 mg/ml have been associated with increased risk for cardiovascular diseases and impaired endothelial functionality. Here, we demonstrate that high concentrations of LDL (1 mg/ml) decreased NOS3 protein and RNA levels in primary human endothelial cells. In addition, RNA sequencing data, in particular splice site usage analysis, showed a shift in NOS3 exon-exon junction reads towards those specifically assigned to nonfunctional transcript isoforms further diminishing the functional NOS3 levels. The reduction in NOS3 was accompanied by decreased migratory capacity, which depends on intact mitochondria and ATP formation. In line with these findings, we also observed a reduced ATP content. While mitochondrial mass was unaffected by high LDL, we found an increase in mitochondrial DNA copy number and mitochondrial RNA transcripts but decreased expression of nuclear genes coding for respiratory chain proteins. Therefore, high LDL treatment most likely results in an imbalance between respiratory chain complex proteins encoded in the mitochondria and in the nucleus resulting in impaired respiratory chain function explaining the reduction in ATP content. In conclusion, high LDL treatment leads to a decrease in active NOS3 and dysregulation of mitochondrial transcription, which is entailed by reduced ATP content and migratory capacity and thus, impairment of endothelial cell functionality.
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9
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Lu S, Edwards MC. Molecular Characterization and Functional Analysis of PR-1-Like Proteins Identified from the Wheat Head Blight Fungus Fusarium graminearum. PHYTOPATHOLOGY 2018; 108:510-520. [PMID: 29117786 DOI: 10.1094/phyto-08-17-0268-r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The group 1 pathogenesis-related (PR-1) proteins originally identified from plants and their homologs are also found in other eukaryotic kingdoms. Studies on nonplant PR-1-like (PR-1L) proteins have been pursued widely in humans and animals but rarely in filamentous ascomycetes. Here, we report the characterization of four PR-1L proteins identified from the ascomycete fungus Fusarium graminearum, the primary cause of Fusarium head blight of wheat and barley (designated FgPR-1L). Molecular cloning revealed that the four FgPR-1L proteins are all encoded by small open reading frames (612 to 909 bp) that are often interrupted by introns, in contrast to plant PR-1 genes that lack introns. Sequence analysis indicated that all FgPR-1L proteins contain the PR-1-specific three-dimensional structure, and one of them features a C-terminal transmembrane (TM) domain that has not been reported for any stand-alone PR-1 proteins. Transcriptional analysis revealed that the four FgPR-1L genes are expressed in axenic cultures and in planta with different spatial or temporal expression patterns. Phylogenetic analysis indicated that fungal PR-1L proteins fall into three major groups, one of which harbors FgPR-1L-2-related TM-containing proteins from both phytopathogenic and human-pathogenic ascomycetes. Low-temperature sodium dodecyl sulfate polyacrylamide gel electrophoresis and proteolytic assays indicated that the recombinant FgPR-1L-4 protein exists as a monomer and is resistant to subtilisin of the serine protease family. Functional analysis confirmed that deletion of the FgPR-1L-4 gene from the fungal genome results in significantly reduced virulence on susceptible wheat. This study provides the first example that the F. graminearum-wheat interaction involves a pathogen-derived PR-1L protein that affects fungal virulence on the host.
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Affiliation(s)
- Shunwen Lu
- United States Department of Agriculture-Agricultural Research Service, Cereal Crops Research Unit, Fargo, ND 58102-2765
| | - Michael C Edwards
- United States Department of Agriculture-Agricultural Research Service, Cereal Crops Research Unit, Fargo, ND 58102-2765
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10
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de Bruin RG, Rabelink TJ, van Zonneveld AJ, van der Veer EP. Emerging roles for RNA-binding proteins as effectors and regulators of cardiovascular disease. Eur Heart J 2018; 38:1380-1388. [PMID: 28064149 DOI: 10.1093/eurheartj/ehw567] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/02/2016] [Indexed: 12/18/2022] Open
Abstract
The cardiovascular system comprises multiple cell types that possess the capacity to modulate their phenotype in response to acute or chronic injury. Transcriptional and post-transcriptional mechanisms play a key role in the regulation of remodelling and regenerative responses to damaged cardiovascular tissues. Simultaneously, insufficient regulation of cellular phenotype is tightly coupled with the persistence and exacerbation of cardiovascular disease. Recently, RNA-binding proteins such as Quaking, HuR, Muscleblind, and SRSF1 have emerged as pivotal regulators of these functional adaptations in the cardiovascular system by guiding a wide-ranging number of post-transcriptional events that dramatically impact RNA fate, including alternative splicing, stability, localization and translation. Moreover, homozygous disruption of RNA-binding protein genes is commonly associated with cardiac- and/or vascular complications. Here, we summarize the current knowledge on the versatile role of RNA-binding proteins in regulating the transcriptome during phenotype switching in cardiovascular health and disease. We also detail existing and potential DNA- and RNA-based therapeutic approaches that could impact the treatment of cardiovascular disease in the future.
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Affiliation(s)
- Ruben G de Bruin
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands.,Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands
| | - Ton J Rabelink
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands.,Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands
| | - Anton Jan van Zonneveld
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands.,Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands
| | - Eric P van der Veer
- Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands.,Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Albinusdreef 2, Leiden 2300RC, The Netherlands
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11
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Abstract
Nitric oxide (NO) is an imperative regulator of the cardiovascular system and is a critical mechanism in preventing the pathogenesis and progression of the diseased heart. The scenario of bioavailable NO in the myocardium is complex: 1) NO is derived from both endogenous NO synthases (endothelial, neuronal, and/or inducible NOSs [eNOS, nNOS, and/or iNOS]) and exogenous sources (entero-salivary NO pathway) and the amount of NO from exogenous sources varies significantly; 2) NOSs are located at discrete compartments of cardiac myocytes and are regulated by distinctive mechanisms under stress; 3) NO regulates diverse target proteins through different modes of post-transcriptional modification (soluble guanylate cyclase [sGC]/cyclic guanosine monophosphate [cGMP]/protein kinase G [PKG]-dependent phosphorylation,
S-nitrosylation, and transnitrosylation); 4) the downstream effectors of NO are multidimensional and vary from ion channels in the plasma membrane to signalling proteins and enzymes in the mitochondria, cytosol, nucleus, and myofilament; 5) NOS produces several radicals in addition to NO (e.g. superoxide, hydrogen peroxide, peroxynitrite, and different NO-related derivatives) and triggers redox-dependent responses. However, nNOS inhibits cardiac oxidases to reduce the sources of oxidative stress in diseased hearts. Recent consensus indicates the importance of nNOS protein in cardiac protection under pathological stress. In addition, a dietary regime with high nitrate intake from fruit and vegetables together with unsaturated fatty acids is strongly associated with reduced cardiovascular events. Collectively, NO-dependent mechanisms in healthy and diseased hearts are better understood and shed light on the therapeutic prospects for NO and NOSs in clinical applications for fatal human heart diseases.
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Affiliation(s)
- Yin Hua Zhang
- Department of Physiology & Biomedical Sciences, College of Medicine, Seoul National University, 103 Dae Hak Ro, Chong No Gu, 110-799 Seoul, Korea, South.,Yanbian University Hospital, Yanji, Jilin Province, 133000, China.,Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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12
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Shimada MK, Sanbonmatsu R, Yamaguchi-Kabata Y, Yamasaki C, Suzuki Y, Chakraborty R, Gojobori T, Imanishi T. Selection pressure on human STR loci and its relevance in repeat expansion disease. Mol Genet Genomics 2016; 291:1851-69. [PMID: 27290643 DOI: 10.1007/s00438-016-1219-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 05/21/2016] [Indexed: 12/30/2022]
Abstract
Short Tandem Repeats (STRs) comprise repeats of one to several base pairs. Because of the high mutability due to strand slippage during DNA synthesis, rapid evolutionary change in the number of repeating units directly shapes the range of repeat-number variation according to selection pressure. However, the remaining questions include: Why are STRs causing repeat expansion diseases maintained in the human population; and why are these limited to neurodegenerative diseases? By evaluating the genome-wide selection pressure on STRs using the database we constructed, we identified two different patterns of relationship in repeat-number polymorphisms between DNA and amino-acid sequences, although both patterns are evolutionary consequences of avoiding the formation of harmful long STRs. First, a mixture of degenerate codons is represented in poly-proline (poly-P) repeats. Second, long poly-glutamine (poly-Q) repeats are favored at the protein level; however, at the DNA level, STRs encoding long poly-Qs are frequently divided by synonymous SNPs. Furthermore, significant enrichments of apoptosis and neurodevelopment were biological processes found specifically in genes encoding poly-Qs with repeat polymorphism. This suggests the existence of a specific molecular function for polymorphic and/or long poly-Q stretches. Given that the poly-Qs causing expansion diseases were longer than other poly-Qs, even in healthy subjects, our results indicate that the evolutionary benefits of long and/or polymorphic poly-Q stretches outweigh the risks of long CAG repeats predisposing to pathological hyper-expansions. Molecular pathways in neurodevelopment requiring long and polymorphic poly-Q stretches may provide a clue to understanding why poly-Q expansion diseases are limited to neurodegenerative diseases.
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Affiliation(s)
- Makoto K Shimada
- Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan.
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan.
- Japan Biological Informatics Consortium, 10F TIME24 Building, 2-4-32 Aomi, Koto-ku, Tokyo, 135-8073, Japan.
| | - Ryoko Sanbonmatsu
- Japan Biological Informatics Consortium, 10F TIME24 Building, 2-4-32 Aomi, Koto-ku, Tokyo, 135-8073, Japan
| | - Yumi Yamaguchi-Kabata
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan
- Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8573, Japan
| | - Chisato Yamasaki
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan
- Japan Biological Informatics Consortium, 10F TIME24 Building, 2-4-32 Aomi, Koto-ku, Tokyo, 135-8073, Japan
| | - Yoshiyuki Suzuki
- Graduate School of Natural Sciences, Nagoya City University, 1 Yamanohata, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, 467-8501, Japan
| | - Ranajit Chakraborty
- Health Science Center, University of North Texas, 3500 Camp Bowie Blvd., Fort Worth, TX, 76107, USA
| | - Takashi Gojobori
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Ibn Al-Haytham Building (West), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Tadashi Imanishi
- National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi Koto-ku, Tokyo, 135-0064, Japan
- Department of Molecular Life Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, 259-1193, Japan
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13
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Farrokh S, Brillen AL, Haendeler J, Altschmied J, Schaal H. Critical regulators of endothelial cell functions: for a change being alternative. Antioxid Redox Signal 2015; 22:1212-29. [PMID: 25203279 DOI: 10.1089/ars.2014.6023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
SIGNIFICANCE The endothelium regulates vessel dilation and constriction, balances hemostasis, and inhibits thrombosis. In addition, pro- and anti-angiogenic molecules orchestrate proliferation, survival, and migration of endothelial cells. Regulation of all these processes requires fine-tuning of signaling pathways, which can easily be tricked into running the opposite direction when exogenous or endogenous signals get out of hand. Surprisingly, some critical regulators of physiological endothelial functions can turn malicious by mere alternative splicing, leading to the expression of protein isoforms with opposite functions. RECENT ADVANCES While reviewing the evidence of alternative splicing on cellular physiology, it became evident that expression of splice factors and their activities are regulated by externally triggered signaling cascades. Furthermore, genome-wide identification of RNA-binding sites of splicing regulatory proteins now offer a glimpse into the splicing code responsible for alternative splicing of molecules regulating endothelial functions. CRITICAL ISSUES Due to the constantly growing number of transcript and protein isoforms, it will become more and more important to identify and characterize all transcripts and proteins regulating endothelial cell functions. One critical issue will be a non-ambiguous nomenclature to keep consistency throughout different laboratories. FUTURE DIRECTIONS RNA-deep sequencing focusing on exon-exon junction needs to more reliably identify alternative splicing events combined with functional analyses that will uncover more splice variants contributing to or inhibiting proper endothelial functions. In addition, understanding the signals mediating alternative splicing and its regulation might allow us to derive new strategies to preserve endothelial function by suppressing or upregulating specific protein isoforms. Antioxid. Redox Signal. 22, 1212-1229.
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Affiliation(s)
- Sabrina Farrokh
- 1 Heisenberg-Group-Environmentally-Induced Cardiovascular Degeneration, IUF-Leibniz Research Institute for Environmental Medicine , Düsseldorf, Germany
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14
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Galluccio E, Cassina L, Russo I, Gelmini F, Setola E, Rampoldi L, Citterio L, Rossodivita A, Kamami M, Colombo A, Alfieri O, Carini M, Bosi E, Trovati M, Piatti P, Monti LD, Casari G. A novel truncated form of eNOS associates with altered vascular function. Cardiovasc Res 2013; 101:492-502. [DOI: 10.1093/cvr/cvt267] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Regulation of vascular function on posttranscriptional level. THROMBOSIS 2013; 2013:948765. [PMID: 24288605 PMCID: PMC3833109 DOI: 10.1155/2013/948765] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/17/2013] [Indexed: 11/17/2022]
Abstract
Posttranscriptional control of gene expression is crucial for regulating plurality of proteins and functional plasticity of the proteome under (patho)physiologic conditions. Alternative splicing as well as micro (mi)RNA-mediated mechanisms play an important role for the regulation of protein expression on posttranscriptional level. Both alternative splicing and miRNAs were shown to influence cardiovascular functions, such as endothelial thrombogenicity and the vascular tone, by regulating the expression of several vascular proteins and their isoforms, such as Tissue Factor (TF) or the endothelial nitric oxide synthase (eNOS). This review will summarize and discuss the latest findings on the (patho)physiologic role of alternative splicing processes as well as of miRNAs on modulation of vascular functions, such as coagulation, thrombosis, and regulation of the vascular tone.
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16
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Cox RH, Fromme SJ. A naturally occurring truncated Cav1.2 α1-subunit inhibits Ca2+ current in A7r5 cells. Am J Physiol Cell Physiol 2013; 305:C896-905. [PMID: 23926129 DOI: 10.1152/ajpcell.00217.2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Alternative splicing of the voltage-gated Ca(2+) (CaV) α1-subunit adds to the functional diversity of Ca(2+) channels. A variant with a 73-nt deletion in exon 15 of the Cav1.2 α1-subunit (Cav1.2Δ73) produced by alternative splicing that predicts a truncated protein has been described, but its function, if any, is unknown. We sought to determine if, by analogy to other truncated CaV α1-subunits, Cav1.2Δ73 acts as an inhibitor of wild-type Cav1.2 currents. HEK-293 cells were transfected with Cav1.2Δ73 in a pIRES vector with CD8 or in pcDNA3.1 with a V5/his COOH-terminal tag plus β2 and α2δ1 accessory subunits and pEGFP. Production of Cav1.2Δ73 protein was confirmed by Western blotting and immunofluorescence. Voltage-clamp studies revealed the absence of functional channels in transfected cells. In contrast, cells transfected with full-length Cav1.2 plus accessory subunits and pEGFP exhibited robust Ca(2+) currents. A7r5 cells exhibited endogenous Cav1.2-based currents that were greatly reduced (>80%) without a change in voltage-dependent activation when transfected with Cav1.2Δ73-IRES-CD8 compared with empty vector or pIRES-CD8 controls. Transfection of A7r5 cells with an analogous Cav2.3Δ73-IRES-CD8 had no effect on Ca(2+) currents. Immunofluorescence showed intracellular, but not plasma membrane, localization of Cav1.2Δ73-V5/his, as well as colocalization with an endoplasmic reticulum marker, ER Organelle Lights. Expression of Cav1.2Δ73 α1-subunits in A7r5 cells inhibits endogenous Cav1.2 currents. The fact that this variant arises naturally by alternative splicing raises the possibility that it may represent a physiological mechanism to modulate Cav1.2 functional activity.
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Affiliation(s)
- Robert H Cox
- Program in Cardiovascular Studies, Lankenau Institute for Medical Research, Main Line Health System, Wynnewood, Pennsylvania
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17
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Carnicer R, Crabtree MJ, Sivakumaran V, Casadei B, Kass DA. Nitric oxide synthases in heart failure. Antioxid Redox Signal 2013; 18:1078-99. [PMID: 22871241 PMCID: PMC3567782 DOI: 10.1089/ars.2012.4824] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 08/07/2012] [Indexed: 12/22/2022]
Abstract
SIGNIFICANCE The regulation of myocardial function by constitutive nitric oxide synthases (NOS) is important for the maintenance of myocardial Ca(2+) homeostasis, relaxation and distensibility, and protection from arrhythmia and abnormal stress stimuli. However, sustained insults such as diabetes, hypertension, hemodynamic overload, and atrial fibrillation lead to dysfunctional NOS activity with superoxide produced instead of NO and worse pathophysiology. RECENT ADVANCES Major strides in understanding the role of normal and abnormal constitutive NOS in the heart have revealed molecular targets by which NO modulates myocyte function and morphology, the role and nature of post-translational modifications of NOS, and factors controlling nitroso-redox balance. Localized and differential signaling from NOS1 (neuronal) versus NOS3 (endothelial) isoforms are being identified, as are methods to restore NOS function in heart disease. CRITICAL ISSUES Abnormal NOS signaling plays a key role in many cardiac disorders, while targeted modulation may potentially reverse this pathogenic source of oxidative stress. FUTURE DIRECTIONS Improvements in the clinical translation of potent modulators of NOS function/dysfunction may ultimately provide a powerful new treatment for many hearts diseases that are fueled by nitroso-redox imbalance.
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Affiliation(s)
- Ricardo Carnicer
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Mark J. Crabtree
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Vidhya Sivakumaran
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, Maryland
| | - Barbara Casadei
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - David A. Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, Maryland
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18
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Kelemen O, Convertini P, Zhang Z, Wen Y, Shen M, Falaleeva M, Stamm S. Function of alternative splicing. Gene 2013; 514:1-30. [PMID: 22909801 PMCID: PMC5632952 DOI: 10.1016/j.gene.2012.07.083] [Citation(s) in RCA: 548] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/21/2012] [Accepted: 07/30/2012] [Indexed: 12/15/2022]
Abstract
Almost all polymerase II transcripts undergo alternative pre-mRNA splicing. Here, we review the functions of alternative splicing events that have been experimentally determined. The overall function of alternative splicing is to increase the diversity of mRNAs expressed from the genome. Alternative splicing changes proteins encoded by mRNAs, which has profound functional effects. Experimental analysis of these protein isoforms showed that alternative splicing regulates binding between proteins, between proteins and nucleic acids as well as between proteins and membranes. Alternative splicing regulates the localization of proteins, their enzymatic properties and their interaction with ligands. In most cases, changes caused by individual splicing isoforms are small. However, cells typically coordinate numerous changes in 'splicing programs', which can have strong effects on cell proliferation, cell survival and properties of the nervous system. Due to its widespread usage and molecular versatility, alternative splicing emerges as a central element in gene regulation that interferes with almost every biological function analyzed.
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Affiliation(s)
- Olga Kelemen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Paolo Convertini
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhaiyi Zhang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Yuan Wen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Manli Shen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Marina Falaleeva
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
| | - Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, United States of America
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19
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Kaitaniemi S, Grön K, Elovaara H, Salmi M, Jalkanen S, Elima K. Functional modulation of vascular adhesion protein-1 by a novel splice variant. PLoS One 2013; 8:e54151. [PMID: 23349812 PMCID: PMC3548902 DOI: 10.1371/journal.pone.0054151] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 12/07/2012] [Indexed: 12/22/2022] Open
Abstract
Vascular Adhesion Protein-1 (VAP-1) is an endothelial adhesion molecule belonging to the primary amine oxidases. Upon inflammation it takes part in the leukocyte extravasation cascade facilitating transmigration of leukocytes into the inflamed tissue. Screening of a human lung cDNA library revealed the presence of an alternatively spliced shorter transcript of VAP-1, VAP-1Δ3. Here, we have studied the functional and structural characteristics of VAP-1Δ3, and show that the mRNA for this splice variant is expressed in most human tissues studied. In comparison to the parent molecule this carboxy-terminally truncated isoform lacks several of the amino acids important in the formation of the enzymatic groove of VAP-1. In addition, the conserved His684, which takes part in coordinating the active site copper, is missing from VAP-1Δ3. Assays using the prototypic amine substrates methylamine and benzylamine demonstrated that VAP-1Δ3 is indeed devoid of the semicarbazide-sensitive amine oxidase (SSAO) activity characteristic to VAP-1. When VAP-1Δ3-cDNA is transfected into cells stably expressing VAP-1, the surface expression of the full-length molecule is reduced. Furthermore, the SSAO activity of the co-transfectants is diminished in comparison to transfectants expressing only VAP-1. The observed down-regulation of both the expression and enzymatic activity of VAP-1 may result from a dominant-negative effect caused by heterodimerization between VAP-1 and VAP-1Δ3, which was detected in co-immunoprecipitation studies. This alternatively spliced transcript adds thus to the repertoire of potential regulatory mechanisms through which the cell-surface expression and enzymatic activity of VAP-1 can be modulated.
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Affiliation(s)
- Sam Kaitaniemi
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Department of Microbiology and Immunology, University of Turku, Turku, Finland
| | - Kirsi Grön
- MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Heli Elovaara
- MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Marko Salmi
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Department of Medical Biochemistry and Genetics, University of Turku, Turku, Finland
| | - Sirpa Jalkanen
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Department of Microbiology and Immunology, University of Turku, Turku, Finland
| | - Kati Elima
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Department of Medical Biochemistry and Genetics, University of Turku, Turku, Finland
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20
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Nitric oxide in skeletal muscle: role on mitochondrial biogenesis and function. Int J Mol Sci 2012; 13:17160-84. [PMID: 23242154 PMCID: PMC3546744 DOI: 10.3390/ijms131217160] [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: 11/01/2012] [Revised: 12/04/2012] [Accepted: 12/05/2012] [Indexed: 01/18/2023] Open
Abstract
Nitric oxide (NO) has been implicated in several cellular processes as a signaling molecule and also as a source of reactive nitrogen species (RNS). NO is produced by three isoenzymes called nitric oxide synthases (NOS), all present in skeletal muscle. While neuronal NOS (nNOS) and endothelial NOS (eNOS) are isoforms constitutively expressed, inducible NOS (iNOS) is mainly expressed during inflammatory responses. Recent studies have demonstrated that NO is also involved in the mitochondrial biogenesis pathway, having PGC-1α as the main signaling molecule. Increased NO synthesis has been demonstrated in the sarcolemma of skeletal muscle fiber and NO can also reversibly inhibit cytochrome c oxidase (Complex IV of the respiratory chain). Investigation on cultured skeletal myotubes treated with NO donors, NO precursors or NOS inhibitors have also showed a bimodal effect of NO that depends on the concentration used. The present review will discuss the new insights on NO roles on mitochondrial biogenesis and function in skeletal muscle. We will also focus on potential therapeutic strategies based on NO precursors or analogs to treat patients with myopathies and mitochondrial deficiency.
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21
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Baccari MC, Traini C, Garella R, Cipriani G, Vannucchi MG. Relaxin exerts two opposite effects on mechanical activity and nitric oxide synthase expression in the mouse colon. Am J Physiol Endocrinol Metab 2012; 303:E1142-50. [PMID: 22932783 DOI: 10.1152/ajpendo.00260.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The hormone relaxin exerts a variety of functions on the smooth muscle of reproductive and nonreproductive organs, most of which occur through a nitric oxide (NO)-mediated mechanism. In the stomach and ileum, relaxin causes muscle relaxation by modulating the activity and expression of different nitric oxide synthase (NOS) isoforms region-dependently. Nothing is known on the effects of relaxin in the colon, the gut region expressing the highest number of neuronal (n) NOSβ-immunoreactive neurons and mainly involved in motor symptoms of pregnancy and menstrual cycle. Therefore, we studied the effects of relaxin exposure in the mouse proximal colon in vitro evaluating muscle mechanical activity and NOS isoform expression. The functional experiments showed that relaxin decreases muscle tone and increases amplitude of spontaneous contractions; the immunohistochemical results showed that relaxin increases nNOSβ and endothelial (e) NOS expression in the neurons and decreases nNOSα and eNOS expression in the smooth muscle cells (SMC). We hypothesized that, in the colon, relaxin primarily increases the activity and expression of nNOSβ and eNOS in the neurons, causing a reduction of the muscle tone. The downregulation of nNOSα and eNOS expression in the SMC associated with increased muscle contractility could be the consequence of continuous exposue of these cells to the NO of neuronal origin. These findings may help to better understand the physiology of NO in the gastrointestinal tract and the role that the "relaxin-NO" system plays in motor disorders such as functional bowel disease.
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MESH Headings
- Anesthetics, Local/pharmacology
- Animals
- Colon/blood supply
- Colon/cytology
- Colon/innervation
- Colon/metabolism
- Colon, Ascending/cytology
- Colon, Ascending/drug effects
- Colon, Ascending/innervation
- Colon, Ascending/metabolism
- Colon, Transverse/cytology
- Colon, Transverse/drug effects
- Colon, Transverse/innervation
- Colon, Transverse/metabolism
- Enzyme Inhibitors/pharmacology
- Female
- Guanylate Cyclase/antagonists & inhibitors
- In Vitro Techniques
- Interstitial Cells of Cajal/cytology
- Interstitial Cells of Cajal/drug effects
- Interstitial Cells of Cajal/metabolism
- Mechanical Phenomena
- Mice
- Mice, Inbred Strains
- Muscle Contraction/drug effects
- Muscle, Smooth/blood supply
- Muscle, Smooth/cytology
- Muscle, Smooth/innervation
- Muscle, Smooth/metabolism
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Nitric Oxide Donors/pharmacology
- Nitric Oxide Synthase Type I/antagonists & inhibitors
- Nitric Oxide Synthase Type I/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/metabolism
- Osmolar Concentration
- Relaxin/metabolism
- Submucous Plexus/cytology
- Submucous Plexus/drug effects
- Submucous Plexus/metabolism
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Affiliation(s)
- M C Baccari
- Department of Physiological Sciences, University of Florence, Florence, Italy
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22
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Davis MJ, Shin CJ, Jing N, Ragan MA. Rewiring the dynamic interactome. MOLECULAR BIOSYSTEMS 2012; 8:2054-2013. [PMID: 22729145 DOI: 10.1039/c2mb25050k] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2025]
Abstract
Transcriptomics continues to provide ever-more evidence that in morphologically complex eukaryotes, each protein-coding genetic locus can give rise to multiple transcripts that differ in length, exon content and/or other sequence features. In humans, more than 60% of loci give rise to multiple transcripts in this way. Motifs that mediate protein-protein interactions can be present or absent in these transcripts. Analysis of protein interaction networks has been a valuable development in systems biology. Interactions are typically recorded for representative proteins or even genes, although exploratory transcriptomics has revealed great spatiotemporal diversity in the output of genes at both the transcript and protein-isoform levels. The increasing availability of high-resolution protein structures has made it possible to identify the domain-domain interactions that underpin many protein interactions. To explore the impact of transcript and isoform diversity we use full-length human cDNAs to interrogate the protein-coding transcriptional output of genes, identifying variation in the inclusion of protein interaction domains. We map these data to a set of high-quality protein interactions, and characterise the variation in network connectivity likely to result. We find strong evidence for altered interaction potential in nearly 20% of genes, suggesting that transcriptional variation can significantly rewire the human interactome.
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Affiliation(s)
- Melissa J Davis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
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23
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Hewing B, Stangl V, Stangl K, Enke-Melzer K, Baumann G, Ludwig A. Circulating angiogenic factors in patients with thromboangiitis obliterans. PLoS One 2012; 7:e34717. [PMID: 22506045 PMCID: PMC3323572 DOI: 10.1371/journal.pone.0034717] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 03/08/2012] [Indexed: 12/14/2022] Open
Abstract
Background Thromboangiitis obliterans (TAO, also known as Buerger's disease) is a non-atherosclerotic inflammatory vascular disease that primarily affects arteries in the extremities of young adult smokers. Since the etiology of TAO is still unknown, therapeutic options are limited. Recent attempts in therapeutic angiogenesis have been promising. Therefore, the aim of our study was to evaluate angiogenic processes and factors including circulating progenitor cells in TAO. Methodology/Principal Findings TAO patients with critical limb ischemia and age- and gender-matched nonsmokers and smokers without cardiovascular disease (n = 12 in each group) were enrolled in the study. Flow cytometric analysis of peripheral blood showed significantly decreased levels of circulating CD45dimCD34+ progenitor cells in TAO patients and in smokers compared to nonsmokers. In contrast to both control groups, the proportion of CD45dimCD34+ progenitor cells co-expressing VEGF receptor-2 (VEGFR2) was significantly elevated in TAO patients. Enzyme-linked immunosorbent assay (ELISA) of common angiogenic factors (such as VEGF) did not clearly point to pro- or antiangiogenic conditions in serum or plasma of TAO patients. Serum of TAO patients and controls was evaluated in proliferation, migration (scratch assay) and spheroid sprouting assays using human umbilical vein endothelial cells (HUVECs). Serum of TAO patients exhibited a diminished sprouting capacity of HUVECs compared to both control groups. Proliferation and migration of endothelial cells were impaired after treatment with serum of TAO patients. Conclusion Levels of circulating progenitor cells were altered in TAO patients compared to healthy nonsmokers and smokers. Furthermore, serum of TAO patients exhibited an antiangiogenic activity (impaired endothelial cell sprouting, migration and proliferation) on endothelial cells, which may contribute to vascular pathology in this patient population.
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Affiliation(s)
- Bernd Hewing
- Medizinische Klinik mit Schwerpunkt Kardiologie und Angiologie, Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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24
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Xu J, Wang S, Zhang M, Wang Q, Asfa S, Zou MH. Tyrosine nitration of PA700 links proteasome activation to endothelial dysfunction in mouse models with cardiovascular risk factors. PLoS One 2012; 7:e29649. [PMID: 22272240 PMCID: PMC3260160 DOI: 10.1371/journal.pone.0029649] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 12/02/2011] [Indexed: 11/19/2022] Open
Abstract
Oxidative stress is believed to cause endothelial dysfunction, an early event and a hallmark in cardiovascular diseases (CVD) including hypertension, diabetes, and dyslipidemia. However, the targets for oxidative stress-mediated endothelial dysfunction in CVD have not been completely elucidated. Here we report that 26S proteasome activation by peroxynitrite (ONOO−) is a common pathway for endothelial dysfunction in mouse models of diabetes, hypertension, and dyslipidemia. Endothelial function, assayed by acetylcholine-induced vasorelaxation, was impaired in parallel with significantly increased 26S proteasome activity in aortic homogenates from streptozotocin (STZ)-induced type I diabetic mice, angiotensin-infused hypertensive mice, and high fat-diets -fed LDL receptor knockout (LDLr−/−) mice. The elevated 26S proteasome activities were accompanied by ONOO−-mediated PA700/S10B nitration and increased 26S proteasome assembly and caused accelerated degradation of molecules (such as GTPCH I and thioredoxin) essential to endothelial homeostasis. Pharmacological (administration of MG132) or genetic inhibition (siRNA knockdown of PA700/S10B) of the 26S proteasome blocked the degradation of the vascular protective molecules and ablated endothelial dysfunction induced by diabetes, hypertension, and western diet feeding. Taken together, these results suggest that 26S proteasome activation by ONOO−-induced PA700/S10B tyrosine nitration is a common route for endothelial dysfunction seen in mouse models of hypertension, diabetes, and dyslipidemia.
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MESH Headings
- Animals
- Blotting, Western
- Cardiovascular Diseases/metabolism
- Cardiovascular Diseases/physiopathology
- Cells, Cultured
- Cysteine Proteinase Inhibitors/pharmacology
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Dyslipidemias/metabolism
- Dyslipidemias/physiopathology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Enzyme Activation/drug effects
- Human Umbilical Vein Endothelial Cells/drug effects
- Human Umbilical Vein Endothelial Cells/metabolism
- Humans
- Hypertension/metabolism
- Hypertension/physiopathology
- Leupeptins/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nitrosation/drug effects
- Peroxynitrous Acid/metabolism
- Peroxynitrous Acid/pharmacology
- Proteasome Endopeptidase Complex/genetics
- Proteasome Endopeptidase Complex/metabolism
- Proteasome Inhibitors
- Protein Subunits/antagonists & inhibitors
- Protein Subunits/genetics
- Protein Subunits/metabolism
- RNA Interference
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
- Risk Factors
- Thioredoxins/metabolism
- Tyrosine/metabolism
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Affiliation(s)
- Jian Xu
- Division of Endocrinology and Diabetes, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
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25
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Sandvik GK, Nilsson GE, Jensen FB. Dramatic increase of nitrite levels in hearts of anoxia-exposed crucian carp supporting a role in cardioprotection. Am J Physiol Regul Integr Comp Physiol 2011; 302:R468-77. [PMID: 22129619 DOI: 10.1152/ajpregu.00538.2011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Nitrite (NO(2)(-)) functions as an important nitric oxide (NO) donor under hypoxic conditions. Both nitrite and NO have been found to protect the mammalian heart and other tissues against ischemia (anoxia)-reoxygenation injury by interacting with mitochondrial electron transport complexes and limiting the generation of reactive oxygen species upon reoxygenation. The crucian carp naturally survives extended periods without oxygen in an active state, which has made it a model for studying how evolution has solved the problems of anoxic survival. We investigated the role of nitrite and NO in the anoxia tolerance of this fish by measuring NO metabolites in normoxic, anoxic, and reoxygenated crucian carp. We also cloned and sequenced crucian carp NO synthase variants and quantified their mRNA levels in several tissues in normoxia and anoxia. Despite falling levels of blood plasma nitrite, the crucian carp showed massive increases in nitrite, S-nitrosothiols (SNO), and iron-nitrosyl (FeNO) compounds in anoxic heart tissue. NO(2)(-) levels were maintained in anoxic brain, liver, and gill tissues, whereas SNO and FeNO increased in a tissue-specific manner. Reoxygenation reestablished normoxic values. We conclude that NO(2)(-) is shifted into the tissues where it acts as NO donor during anoxia, inducing cytoprotection under anoxia/reoxygenation. This can be especially important in the crucian carp heart, which maintains output in anoxia. NO(2)(-) is currently tested as a therapeutic drug against reperfusion damage of ischemic hearts, and the present study provides evolutionary precedent for such an approach.
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Affiliation(s)
- Guro K Sandvik
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway.
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Sharina IG, Cote GJ, Martin E, Doursout MF, Murad F. RNA splicing in regulation of nitric oxide receptor soluble guanylyl cyclase. Nitric Oxide 2011; 25:265-74. [PMID: 21867767 DOI: 10.1016/j.niox.2011.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 08/01/2011] [Accepted: 08/04/2011] [Indexed: 11/19/2022]
Abstract
Soluble guanylyl cyclase (sGC) is a key protein in the nitric oxide (NO)/-cGMP signaling pathway. sGC activity is involved in a number of important physiological processes including smooth muscle relaxation, neurotransmission and platelet aggregation and adhesion. Regulation of sGC expression and activity emerges as a crucial factor in control of sGC function in normal and pathological conditions. Recently accumulated evidence strongly indicates that the regulation of sGC expression is a complex process modulated on several levels including transcription, post-transcriptional regulation, translation and protein stability. Presently our understanding of mechanisms governing regulation of sGC expression remains very limited and awaits systematic investigation. Among other ways, the expression of sGC subunits is modulated at the levels of mRNA abundance and transcript diversity. In this review we summarize available information on different mechanisms (including transcriptional activation, mRNA stability and alternative splicing) involved in the modulation of mRNA levels of sGC subunits in response to various environmental clues. We also summarize and cross-reference the information on human sGC splice forms available in the literature and in genomic databases. This review highlights the fact that the study of the biological role and regulation of sGC splicing will bring new insights to our understanding of NO/cGMP biology.
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Affiliation(s)
- Iraida G Sharina
- Department of Internal Medicine, University of Texas Health Science Center, Houston, TX, USA.
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Slyvka Y, Wang Z, Yee J, Inman SR, Nowak FV. Antioxidant diet, gender and age affect renal expression of nitric oxide synthases in obese diabetic rats. Nitric Oxide 2011; 24:50-60. [DOI: 10.1016/j.niox.2010.11.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 08/28/2010] [Accepted: 11/15/2010] [Indexed: 01/07/2023]
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Moreno-López B. Local isoform-specific NOS inhibition: a promising approach to promote motor function recovery after nerve injury. J Neurosci Res 2010; 88:1846-57. [PMID: 20143424 DOI: 10.1002/jnr.22353] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Physical injury to a nerve is the most frequent cause of acquired peripheral neuropathy, which is responsible for loss of motor, sensory and/or autonomic functions. Injured axons in the peripheral nervous system maintain the capacity to regenerate in adult mammals. However, after nerve transection, stumps of damaged nerves must be surgically joined to guide regenerating axons into the distal nerve stump. Even so, severe functional limitations persist after restorative surgery. Therefore, the identification of molecules that regulate degenerative and regenerative processes is indispensable in developing therapeutic tools to accelerate and improve functional recovery. Here, I consider the role of nitric oxide (NO) synthesized by the three major isoforms of NO synthases (NOS) in motor neuropathy. Neuronal NOS (nNOS) seems to be the primary source of NO that is detrimental to the survival of injured motoneurons. Endothelial NOS (eNOS) appears to be the major source of NO that interferes with axonal regrowth, at least soon after injury. Finally, NO derived from inducible NOS (iNOS) or nNOS is critical to the process of lipid breakdown for Wallerian degeneration and thereby benefits axonal regrowth. Specific inhibitors of these isoforms can be used to protect injured neurons from degeneration and promote axonal regeneration. A cautious proposal for the treatment of acquired motor neuropathy using therapeutic tools that locally interfere with eNOS/nNOS activities seems to merit consideration.
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29
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Gasanova VK, Ryadninskaya NV, Gaillard C, Strauss F, Belitsky GA, Yakubovskaya MG. Invasion of complementary oligonucleotides into (CA/TG)31 repetitive region of linear and circular DNA duplexes. Mol Biol 2010. [DOI: 10.1134/s0026893310030155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Jones R, Baker MB, Weber M, Harrison DG, Bao G, Searles CD. Molecular beacons can assess changes in expression and 3'-polyadenylation of human eNOS mRNA. Am J Physiol Cell Physiol 2008; 296:C498-504. [PMID: 19109525 DOI: 10.1152/ajpcell.00462.2008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The endothelium plays an essential role in maintaining vascular homeostasis, and it fulfills this role by modulating intracellular signaling and gene expression in response to chemical and mechanical stimuli. Assessing changes in endothelial gene expression is essential to understanding how physiological and pathophysiological processes modulate vascular homeostasis. Here we describe the use of molecular beacons to rapidly and quantitatively assess expression and 3'-polyadenylation of a gene that is important for vascular homeostasis, endothelial nitric oxide synthase (eNOS). Single- and dual-fluorescence resonance energy transfer (FRET) molecular beacon hybridization assays were developed to measure changes in mRNA levels and 3'-polyadenylation, respectively, in primary human endothelial cell cultures subjected to laminar shear stress or statin treatment. Optimized beacon hybridization assays took approximately 15 min to perform, and eNOS mRNA levels were validated by quantitative real-time RT-PCR. Competitive inhibition assays and posttranscriptional silencing of eNOS expression were used to verify the specificity of molecular beacon fluorescence. Finally, the dual-FRET method was used to assess eNOS polyadenylation in tissues isolated from mice subjected to exercise training. These data demonstrate that molecular beacons can be used to rapidly and efficiently measure endothelial gene expression and 3'-polyadenylation. This approach could easily be adapted for studies of other endothelial genes and has promise for applications in live endothelial cells.
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Affiliation(s)
- Rachel Jones
- Div. of Cardiology, Emory Univ. School of Medicine, Atlanta, GA 30322, USA
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Lu SW, Tian D, Borchardt-Wier HB, Wang X. Alternative splicing: A novel mechanism of regulation identified in the chorismate mutase gene of the potato cyst nematode Globodera rostochiensis. Mol Biochem Parasitol 2008; 162:1-15. [DOI: 10.1016/j.molbiopara.2008.06.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 05/13/2008] [Accepted: 06/03/2008] [Indexed: 11/25/2022]
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Eisenreich A, Boltzen U, Poller W, Schultheiss HP, Rauch U. Effects of the Cdc2-like kinase-family and DNA topoisomerase I on the alternative splicing of eNOS in TNF-α-stimulated human endothelial cells. Biol Chem 2008; 389:1333-8. [DOI: 10.1515/bc.2008.152] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Nitric oxide (NO) is synthesized by endothelial nitric oxide synthase (eNOS) and plays an important role in vascular homeostasis and cardiovascular diseases. It has recently been shown that increased expression of alternatively spliced eNOS isoforms eNOS 13A, B and C and heterodimerization with ‘full-length’ eNOS is associated with a decreased eNOS activity. The regulatory pathways enabling this phenomenon are completely unknown. This study examined the effect of Cdc2-like kinases and DNA topoisomerase I on eNOS splicing in TNF-α-induced human umbilical vein endothelial cells (HUVECs). We found that inhibition of DNA topoisomerase I, but not Cdc2-like kinases, prevents the TNF-α-induced increase in eNOS isoform expression and NO reduction in HUVEC. Moreover, we show that the inhibition of DNA topoisomerase I or the Cdc2-like kinases differently modulates the phosphorylation of the serine/arginine-rich proteins SRp75 and SRp55. Our results demonstrate, for the first time, that DNA topoisomerase I but not Cdc2-like kinases serves as an important regulator of the differential eNOS isoform expression in endothelial cells, thereby modulating the TNF-α-induced eNOS activity switch.
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Ugai K, Nishimura K, Fukino K, Nakamura T, Ueno K. Functional analysis of transcriptional activity of cytosine and adenine (CA) repeats polymorphism in the estrogen receptor beta gene. J Toxicol Sci 2008; 33:237-40. [PMID: 18544915 DOI: 10.2131/jts.33.237] [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: 11/02/2022]
Abstract
Cytosine and adenine (CA) repeats polymorphism (D14S1026) iterating "cytosine and adenine" nucleotide motifs is one of the genomic microsatellites in intron 5 of the estrogen receptor beta (ER beta) gene (14q22-24). Relations between CA repeats polymorphism and several diseases have been shown. Although the relation between number of CA repeats and gene transcription has been actively studied using several genes, results have remained contradictory until this time. In this study, we examined the functional effects of CA repeats polymorphism on transcriptional activity based on our knowledge of the ER beta gene. After preparing four types of reporter gene constructs containing 15, 18, 24 or 27 CA repeats, luciferase reporter gene assays were performed. Relative luciferase activities of these constructs were not significantly different from that of the no inserted vector and variation of CA repeats did not affect these activities. Our results indicate that CA repeats polymorphism might not only affect transcriptional activity but also other processes of gene expressions. Further studies are needed to clarify the specific functions of CA repeats polymorphism in the ER beta gene.
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Galluccio E, Piatti P, Citterio L, Lucotti PCG, Setola E, Cassina L, Oldani M, Zavaroni I, Bosi E, Colombo A, Alfieri O, Casari G, Reaven GM, Monti LD. Hyperinsulinemia and impaired leptin-adiponectin ratio associate with endothelial nitric oxide synthase polymorphisms in subjects with in-stent restenosis. Am J Physiol Endocrinol Metab 2008; 294:E978-86. [PMID: 18349107 DOI: 10.1152/ajpendo.00003.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Little is known about the association of endothelial nitric oxide synthase (NOS3) gene polymorphisms and the presence of insulin resistance and the early evolution of atherosclerosis in nondiabetic subjects with cardiovascular disease (CAD) and stent implantation. The present study was performed in an attempt to better understand whether metabolic, endothelial, and angiographic findings characteristic of subjects with cardiovascular disease and in-stent restenosis are related to NOS3 variants. This is a case-control study performed from 2002 to 2006. All subjects admitted to the study were recruited in the Nord-Centre of Italy, most from Milan and its surrounding towns. Measures of glucose tolerance, insulin sensitivity, markers of endothelial dysfunction, forearm vasodilation, and adipokine levels were determined and associated to the frequency of two single-nucleotide polymorphisms of NOS3, i.e., Glu298Asp (rs1799983, G/T) and rs753482 (intron 18 A/C). A total of 747 subjects, not known to have diabetes, were evaluated: 333 subjects had asymptomatic CAD, 106 subjects had unstable angina and were evaluated for in-stent restenosis 6 mo after stent placement, and 308 were control subjects. The presence of TT and CC minor alleles was significantly greater in case groups compared with control subjects. At phenotypic level, subjects with the polymorphisms were characterized by hyperinsulinemia and reduced reactive hyperemia, whereas increased leptin and decreased adiponectin levels were present in subjects with restenosis in the presence of reduced minimal lumen diameter and length of stenosis almost doubled. Hyperinsulinemia, endothelial dysfunction, and a more atherogenic profile seem to be peculiar features of subjects with asymptomatic CAD and restenosis carrying NOS3 gene variants.
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Winchester JS, Rouchka EC, Rowland NS, Rice NA. In Silico characterization of phosphorylase kinase: evidence for an alternate intronic polyadenylation site in PHKG1. Mol Genet Metab 2007; 92:234-42. [PMID: 17692548 PMCID: PMC2706538 DOI: 10.1016/j.ymgme.2007.06.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Accepted: 06/25/2007] [Indexed: 01/21/2023]
Abstract
Phosphorylase kinase (PhK), the key enzyme that regulates glycogenolysis, has traditionally been thought to be expressed predominantly in muscle and liver. In this study, we show by two different database searches (Expressed Sequence Tag and UniGene) that PhK gene expression occurs in at least 28-36 different tissues, and that the genes encoding the alpha, beta, and gamma subunits of PhK undergo extensive transcriptional processing. In particular, we have identified exon 6 of PHKG1 as a 3' composite terminal exon due to the presence of a weak polyadenylation and cleavage site in intron 6. We have verified biochemically that transcriptional processing of PHKG1 does occur in vivo; mRNA corresponding to the alternate variant is expressed in skeletal muscle, brain, heart, and tongue. In silico translation of this mRNA yields a PhK gamma subunit that contains the first 181 residues of the protein, followed by an additional 21 amino acids. The implication of this alternate processing is discussed within the context of gamma catalysis and regulation.
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Affiliation(s)
| | - Eric C. Rouchka
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, Kentucky 40292, USA
| | | | - Nancy A. Rice
- Corresponding Author: Nancy A. Rice, Ph.D., Department of Biology, 1906 College Heights Boulevard #11080, Western Kentucky University, Bowling Green, Kentucky 42101-1080, Telephone: 270.745.5995, Telefax: 270.745.6856,
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