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Fadanni GP, Leão AHFF, Granzotto N, Pereira AG, de Gois AM, Anjos PAR, Linder ÁE, Santos JR, Silva RH, Izídio GS. Genetic effects in a progressive model of parkinsonism induced by reserpine. Psychopharmacology (Berl) 2023; 240:1131-1142. [PMID: 36964320 DOI: 10.1007/s00213-023-06350-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 02/27/2023] [Indexed: 03/26/2023]
Abstract
OBJECTIVE AND METHODS We investigated the locomotor, emotional, physiological, and neurobiological effects induced by low-dose reserpine repeated treatment (0.1 mg/kg; 14 injections) in males from the Lewis (LEW), Spontaneously Hypertensive Rats (SHR), and SHR.LEW-(D4Rat76-D4Mgh11) (SLA16) isogenic rat strains, which have different genetic backgrounds on chromosome 4. Behavioral responses in the catalepsy, open-field, and oral movements' tests were coupled with blood pressure, body weight, and striatal tyrosine hydroxylase (TH) level assessments to establish neurobiological comparisons between reserpine-induced impairments and genetic backgrounds RESULTS: Results revealed the SHR strain was more sensitive in the catalepsy test and exhibited higher TH immunoreactivity in the dorsal striatum. The SLA16 strain presented more oral movements, suggesting increased susceptibility to develop oral dyskinesia. CONCLUSIONS Our results showed the efficacy of repeated treatment with a low dose of reserpine and demonstrated, for the first time, the genetic influence of a specific region of chromosome 4 on the expression of these effects.
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Affiliation(s)
- Guilherme Pasetto Fadanni
- Graduate Program of Pharmacology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | | | - Natalli Granzotto
- Graduate Program of Pharmacology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Aline Guimarães Pereira
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Auderlan Mendonça de Gois
- Laboratory of Behavioral and Evolutionary Neurobiology, Department of Biosciences, Universidade Federal de Sergipe, Itabaiana, Brazil
| | - Pâmela Andressa Ramborger Anjos
- Graduate Program of Pharmacology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Áurea Elizabeth Linder
- Graduate Program of Pharmacology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - José Ronaldo Santos
- Laboratory of Behavioral and Evolutionary Neurobiology, Department of Biosciences, Universidade Federal de Sergipe, Itabaiana, Brazil
| | - Regina Helena Silva
- Department of Pharmacology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Geison Souza Izídio
- Graduate Program of Pharmacology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
- Biological Sciences Center, Cellular Biology, Embryology and Genetics Department, Behavioral Genetics Laboratory, Federal University of Santa Catarina, 88.040-900, Florianópolis, SC, Brazil.
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Dube P, Khalaf FK, DeRiso A, Mohammed CJ, Connolly JA, Battepati D, Lad A, Breidenbach JD, Kleinhenz AL, Khatib-Shahidi B, Patel M, Tassavvor I, Gohara AF, Malhotra D, Morgan EE, Haller ST, Kennedy DJ. Cardioprotective Role for Paraoxonase-1 in Chronic Kidney Disease. Biomedicines 2022; 10:2301. [PMID: 36140402 PMCID: PMC9496500 DOI: 10.3390/biomedicines10092301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 09/05/2022] [Accepted: 09/07/2022] [Indexed: 11/17/2022] Open
Abstract
Paraoxonase-1 (PON-1) is a hydrolytic enzyme associated with HDL, contributing to its anti-inflammatory, antioxidant, and anti-atherogenic properties. Deficiencies in PON-1 activity result in oxidative stress and detrimental clinical outcomes in the context of chronic kidney disease (CKD). However, it is unclear if a decrease in PON-1 activity is mechanistically linked to adverse cardiovascular events in CKD. We investigated the hypothesis that PON-1 is cardioprotective in a Dahl salt-sensitive model of hypertensive renal disease. Experiments were performed on control Dahl salt-sensitive rats (SSMcwi, hereafter designated SS-WT rats) and mutant PON-1 rats (SS-Pon1em1Mcwi, hereafter designated SS-PON-1 KO rats) generated using CRISPR gene editing technology. Age-matched 10-week-old SS and SS-PON-1 KO male rats were maintained on high-salt diets (8% NaCl) for five weeks to induce hypertensive renal disease. Echocardiography showed that SS-PON-1 KO rats but not SS-WT rats developed compensated left ventricular hypertrophy after only 4 weeks on the high-salt diet. RT-PCR analysis demonstrated a significant increase in the expression of genes linked to cardiac hypertrophy, inflammation, and fibrosis, as well as a significant decrease in genes essential to left ventricular function in SS-PON-1 KO rats compared to SS-WT rats. A histological examination also revealed a significant increase in cardiac fibrosis and immune cell infiltration in SS-PON-1 KO rats, consistent with their cardiac hypertrophy phenotype. Our data suggest that a loss of PON-1 in the salt-sensitive hypertensive model of CKD leads to increased cardiac inflammation and fibrosis as well as a molecular and functional cardiac phenotype consistent with compensated left ventricular hypertrophy.
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Affiliation(s)
- Prabhatchandra Dube
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Fatimah K. Khalaf
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
- Department of Clinical Pharmacy, University of Alkafeel, Najaf 54001, Iraq
| | - Armelle DeRiso
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Chrysan J. Mohammed
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Jacob A. Connolly
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Dhanushya Battepati
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Apurva Lad
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Joshua D. Breidenbach
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Andrew L. Kleinhenz
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Bella Khatib-Shahidi
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Mitra Patel
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Iman Tassavvor
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Amira F. Gohara
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Deepak Malhotra
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - Eric E. Morgan
- Department of Surgery, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43606, USA
| | - Steven T. Haller
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
| | - David J. Kennedy
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH 43606, USA
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Turbeville HR, Johnson AC, Garrett MR, Dent EL, Sasser JM. Nitric oxide and oxidative stress pathways do not contribute to sex differences in renal injury and function in Dahl SS/Jr rats. Physiol Rep 2020; 8:e14440. [PMID: 32652814 PMCID: PMC7354091 DOI: 10.14814/phy2.14440] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 04/15/2020] [Indexed: 12/13/2022] Open
Abstract
The burden of hypertension in the United States is increasing and yields significant morbidity and mortality, and sex differences in hypertension are widely recognized. Reduced nitric oxide (NO) bioavailability and increased oxidative stress are known to contribute to the pathogenesis of hypertensive renal injury, and but their contributions to sex differences in injury progression of are undefined. Our purpose was to test the hypothesis that male hypertensive rats have accelerated renal injury compared to females and to determine the contributions of the nitric oxide pathway and oxidative stress in these differences. Male and female Dahl SS/Jr rats, a model that spontaneously develops hypertension with age, were allowed to age on a 0.3% NaCl diet until 3 or 6 months of age, at which points blood pressure was measured and plasma, tissue, and urine were collected. While no significant sex differences in blood pressure were present at either time point, renal injury measured by urine protein excretion was more severe (male = 44.9 ± 6; female = 15±3 mg/day/100 g bw, p = .0001), and renal function was reduced (male = 0.48 ± 0.02; female = 0.7 ± 0.03 ml min-1 g-1 kw, p = .001) in males compared to females with age. Both male and female rats exhibited reduced nitric oxide metabolites (3 months: male = 0.65 ± 0.1; female = 0.74 ± 0.3; 6 months: male = 0.16 ± 0.1; female = 0.41 ± 0.1 ml min-1 g-1 kw, p, age = 0.02, p, sex = 0.3). Levels of urinary TBARS were similar (3 months: male = 20±1.5; female = 23±1.8; 6 months: male = 26±4.8; female = 23±4.7µM day g-1 kw, p, age = 0.4, p, sex = 0.9), extracellular superoxide dismutase (EC SOD) mRNA was greater in females (3 months: male = 0.35 ± 0.03; female = 1.4 ± 0.2; 6 months: male = 0.4 ± 0.05; female = 1.3 ± 0.1 normalized counts, p, age = 0.7, p, sex < 0.0001), but EC SOD protein expression was not different (3 months: male = 0.01 ± 0.002; female = 0.01 ± 0.002; 6 months: male = 0.02 ± 0.004; female = 0.01 ± 0.002 relative density, p, age = 0.2, p, sex = 0.8). These data support the presence of significant sex differences in renal injury and function in the Dahl S rat and identify a need for further study into the mechanisms involved.
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Affiliation(s)
- Hannah R. Turbeville
- Department of Pharmacology and ToxicologyUniversity of Mississippi Medical CenterJacksonMSUSA
| | - Ashley C. Johnson
- Department of Pharmacology and ToxicologyUniversity of Mississippi Medical CenterJacksonMSUSA
| | - Michael R. Garrett
- Department of Pharmacology and ToxicologyUniversity of Mississippi Medical CenterJacksonMSUSA
| | - Elena L. Dent
- Department Physiology and BiophysicsUniversity of Mississippi Medical CenterJacksonMSUSA
| | - Jennifer M. Sasser
- Department of Pharmacology and ToxicologyUniversity of Mississippi Medical CenterJacksonMSUSA
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Rapp JP, Garrett MR. Will the real Dahl S rat please stand up? Am J Physiol Renal Physiol 2019; 317:F1231-F1240. [PMID: 31545925 DOI: 10.1152/ajprenal.00359.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- John P Rapp
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio
| | - Michael R Garrett
- Department of Pharmacology, University of Mississippi Medical Center, Jackson, Mississippi
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Padmanabhan S, Joe B. Towards Precision Medicine for Hypertension: A Review of Genomic, Epigenomic, and Microbiomic Effects on Blood Pressure in Experimental Rat Models and Humans. Physiol Rev 2017; 97:1469-1528. [PMID: 28931564 PMCID: PMC6347103 DOI: 10.1152/physrev.00035.2016] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 04/28/2017] [Accepted: 04/29/2017] [Indexed: 12/11/2022] Open
Abstract
Compelling evidence for the inherited nature of essential hypertension has led to extensive research in rats and humans. Rats have served as the primary model for research on the genetics of hypertension resulting in identification of genomic regions that are causally associated with hypertension. In more recent times, genome-wide studies in humans have also begun to improve our understanding of the inheritance of polygenic forms of hypertension. Based on the chronological progression of research into the genetics of hypertension as the "structural backbone," this review catalogs and discusses the rat and human genetic elements mapped and implicated in blood pressure regulation. Furthermore, the knowledge gained from these genetic studies that provide evidence to suggest that much of the genetic influence on hypertension residing within noncoding elements of our DNA and operating through pervasive epistasis or gene-gene interactions is highlighted. Lastly, perspectives on current thinking that the more complex "triad" of the genome, epigenome, and the microbiome operating to influence the inheritance of hypertension, is documented. Overall, the collective knowledge gained from rats and humans is disappointing in the sense that major hypertension-causing genes as targets for clinical management of essential hypertension may not be a clinical reality. On the other hand, the realization that the polygenic nature of hypertension prevents any single locus from being a relevant clinical target for all humans directs future studies on the genetics of hypertension towards an individualized genomic approach.
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Affiliation(s)
- Sandosh Padmanabhan
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; and Center for Hypertension and Personalized Medicine; Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Bina Joe
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; and Center for Hypertension and Personalized Medicine; Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
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6
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Cheng X, Waghulde H, Mell B, Morgan EE, Pruett-Miller SM, Joe B. Positional cloning of quantitative trait nucleotides for blood pressure and cardiac QT-interval by targeted CRISPR/Cas9 editing of a novel long non-coding RNA. PLoS Genet 2017; 13:e1006961. [PMID: 28827789 PMCID: PMC5578691 DOI: 10.1371/journal.pgen.1006961] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/31/2017] [Accepted: 08/07/2017] [Indexed: 01/11/2023] Open
Abstract
Multiple GWAS studies have reported strong association of cardiac QT-interval to a region on HSA17. Interestingly, a rat locus homologous to this region is also linked to QT-intervals. The high resolution positional mapping study located the rat QT-interval locus to a <42.5kb region on RNO10. This region contained no variants in protein-coding sequences, but a prominent contiguous 19bp indel polymorphism was noted within a novel predicted long non-coding RNA (lncRNA), which we named as Rffl-lnc1. To assess the candidacy of this novel lncRNA on QT-interval, targeted CRISPR/Cas9 based genome-engineering approaches were applied on the rat strains used to map this locus. Targeted disruption of the rat Rffl-lnc1 locus caused aberrant, short QT-intervals and elevated blood pressure. Further, to specifically examine the significance of the 19bp polymorphism within the Rffl-lnc1 locus, a CRISPR/Cas9 based targeted knock-in rescue model was constructed by inserting the 19bp into the strain which contained the deletion polymorphism. The knock-in alleles successfully rescued the aberrant QT-interval and blood pressure phenotypes. Further studies revealed that the 19bp polymorphism was necessary and sufficient to recapitulate the phenotypic effect of the previously mapped <42.5kb rat locus. To our knowledge, this study is the first demonstration of a combination of both CRISPR/Cas9 based targeted disruption as well as CRISPR/Cas9 based targeted knock-in rescue approaches applied for a mammalian positional cloning study, which defines the quantitative trait nucleotides (QTNs) within a rat long non-coding RNA as being important for the pleiotropic regulation of both cardiac QT-intervals and blood pressure. Diseases of the cardiovascular system such as essential hypertension do not have a clear cause, but are known to run in families. The inheritance patterns of essential hypertension and other cardiac diseases suggest that they are not due to a single defective gene but instead are caused by multiple genetic defects that are inherited together in a patient. This complex inheritance makes it difficult to pinpoint the underlying defects. Here, we describe a panel of genetically-engineered rats, using which we have discovered a novel gene, which does not code for any protein, as a gene required for maintenance of normal blood pressure. Structural defects within this non-coding RNA cause hypertension and cardiac short-QT interval. Further, by performing genome surgery to correct the gene defect, we demonstrate the precise error in nucleotides that was inherited and caused hypertension and cardiac short-QT interval syndrome.
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Affiliation(s)
- Xi Cheng
- Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - Harshal Waghulde
- Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - Blair Mell
- Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
| | - Eric E. Morgan
- Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
- Department of Radiology, University of Toledo Medical Center, Toledo, OH, United States of America
| | - Shondra M. Pruett-Miller
- Department of Cell & Molecular Biology, Center for Advanced Genome Engineering, St. Jude Children’s Research Hospital, Memphis, TN, United States of America
| | - Bina Joe
- Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States of America
- * E-mail:
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Joe B. Dr Lewis Kitchener Dahl, the Dahl rats, and the "inconvenient truth" about the genetics of hypertension. Hypertension 2015; 65:963-9. [PMID: 25646295 PMCID: PMC4393342 DOI: 10.1161/hypertensionaha.114.04368] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 12/29/2014] [Indexed: 12/28/2022]
Abstract
Lewis K. Dahl is regarded as an iconic figure in the field of hypertension research. During the 1960s and 1970s he published several seminal articles in the field that shed light on the relationship between salt and hypertension. Further, the Dahl rat models of hypertension that he developed by a selective breeding strategy are among the most widely used models for hypertension research. To this day, genetic studies using this model are ongoing in our laboratory. While Dr. Dahl is known for his contributions to the field of hypertension, very little, if any, of his personal history is documented. This article details a short biography of Dr. Lewis Dahl, the history behind the development of the Dahl rats and presents an overview of the results obtained through the genetic analysis of the Dahl rat as an experimental model to study the inheritance of hypertension.
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Affiliation(s)
- Bina Joe
- From the Department of Physiology and Pharmacology, Center for Hypertension and Personalized Medicine and Program in Physiological Genomics, University of Toledo College of Medicine and Life Sciences, OH.
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Song W, Gao LL, Zhen LL. Whole mitochondrial genome sequence and mutations of the hypertension model inbred rat strain (Muridae; Rattus). Mitochondrial DNA A DNA Mapp Seq Anal 2014; 27:1245-6. [PMID: 25391027 DOI: 10.3109/19401736.2014.945539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We reported the complete mitochondrial genome sequencing of a important hypertension model inbred rat strain for the first time. The total length of the mitogenome was 16,310 bp. It harbored 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and 1 non-coding control region. The mutation events contained in this strain were also reported.
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Affiliation(s)
- Wei Song
- a Department of Thyroid Breast Surgery , Huaian First People's Hospital, Nanjing Medical University , Huaian , People's Republic of China and
| | - Lin-lin Gao
- b Department of Cardiology , Taizhou People's Hospital, Nantong Medical College , Taizhou , People's Republic of China
| | - Lin-lin Zhen
- a Department of Thyroid Breast Surgery , Huaian First People's Hospital, Nanjing Medical University , Huaian , People's Republic of China and
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Rapp JP. Theoretical model for gene-gene, gene-environment, and gene-sex interactions based on congenic-strain analysis of blood pressure in Dahl salt-sensitive rats. Physiol Genomics 2013; 45:737-50. [PMID: 23757391 DOI: 10.1152/physiolgenomics.00046.2013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
There is a significant literature describing quantitative trait loci (QTL) controlling blood pressure (BP) in the Dahl salt-sensitive (S) rat. In studies to identify the genes underlying BP QTL it has been common practice to place chromosomal segments from low BP strains on the genetic background of the S rat and then reduce the congenic segments by substitution mapping. The present work suggests a model to simulate genetic interactions found using such congenic strains. The QTL are considered to be switches that can be either in series or in parallel represented by the logic operators AND or OR, respectively. The QTL switches can be on/off switches but are also allowed specific leak properties. The QTL switches are represented by a "universal" switch consisting of two molecules binding to form a complex. Genetic inputs enter the model as allelic products of one of the binding molecules and environmental variation (including dietary salt- and sex-related differences) enters as an influence on the concentration of the other binding molecule. The pairwise interactions of QTL are very well simulated and fall into recognizable patterns. There is, however, often more than one assumed model to predict a given pattern so that all patterns do not necessarily have a unique solution. Nevertheless, the models obtained provide a framework for placing the QTL in pathways relative to one another. Moreover, based on their leak properties pairs of QTL could be identified in which one QTL may alter the properties of the other QTL.
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Affiliation(s)
- John P Rapp
- Physiological Genomics Laboratory, Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio, USA. )
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10
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Pillai R, Waghulde H, Nie Y, Gopalakrishnan K, Kumarasamy S, Farms P, Garrett MR, Atanur SS, Maratou K, Aitman TJ, Joe B. Isolation and high-throughput sequencing of two closely linked epistatic hypertension susceptibility loci with a panel of bicongenic strains. Physiol Genomics 2013; 45:729-36. [PMID: 23757393 DOI: 10.1152/physiolgenomics.00077.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Interactions or epistasis between genetic factors may contribute to "missing heritability." While linkage analyses detect epistasis, defining the limits of the interacting segments poses a significant challenge especially when the interactions are between loci in close proximity. The goal of the present study was to isolate two such epistatic blood pressure (BP) loci on rat chromosome 5. A panel of S.LEW bicongenic strains along with the corresponding monocongenic strains was constructed. BP of each set comprising of one bicongenic and two corresponding monocongenic strains were determined along with the parental Salt-sensitive (S) strain. Epistasis was observed in one out of four sets of congenic strains, wherein systolic blood pressures (SBP) of the two monocongenic strains S.LEW(5)x6Bx9x5a and S.LEW(5)x6Bx9x5b were comparable to that of S, but the SBP of the bicongenic strain S.LEW(5)x6Bx9x5 (157 ± 4.3 mmHg) was significantly lower than that of S (196 ± 6.8 mmHg, P < 0.001). A two-way ANOVA indicated significant interactions between the LEW alleles at the two loci. The interacting loci were 2.02 Mb apart and located within genomic segments spanning 7.77 and 4.18 Mb containing 7,360 and 2,753 candidate variants, respectively. The current study demonstrates definitive evidence for epistasis and provides genetic tools for further dissection of the isolated epistatic BP loci.
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Affiliation(s)
- Resmi Pillai
- Center for Hypertension and Personalized Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
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Koh-Tan HHC, McBride MW, McClure JD, Beattie E, Young B, Dominiczak AF, Graham D. Interaction between chromosome 2 and 3 regulates pulse pressure in the stroke-prone spontaneously hypertensive rat. Hypertension 2013; 62:33-40. [PMID: 23648703 DOI: 10.1161/hypertensionaha.111.00814] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In an F2 cross between stroke-prone spontaneously hypertensive (SHRSP) and Wistar Kyoto (WKY) rats, we previously identified blood pressure quantitative trait loci (QTL) on rat chromosome (RNO) 2 and a pulse pressure QTL on RNO3. The aims of this study were to confirm the QTL on RNO3 and to investigate interaction between RNO2 and RNO3 loci through the generation and phenotypic assessment of single RNO3 congenic (SP.WKY(Gla)3a) and bicongenic (SP.WKY(Gla)2a/3a) strains. Hemodynamic profiling, vascular function, and renal histology were examined in these newly generated strains along with the previously reported RNO2 congenic strain (SP.WKY(Gla)2a). Our results demonstrate significant equivalent reduction in systolic, diastolic, and pulse pressure phenotypes in SP.WKY(Gla)3a and SP.WKY(Gla)2a rats, whereas greater reductions were observed with the SP.WKY(Gla)2a/3a bicongenic strain achieving blood pressure levels similar to normotensive WKY rats. Epistasis was observed between pulse pressure QTL on RNO2 and 3 at baseline and during 1% salt challenge. Vascular function and renal pathology studies indicate that QTL on RNO3 are responsible for salt-induced kidney pathology, whereas QTL on RNO2 seem to have greater impact on vascular function. RNO3 congenic and bicongenic strains have confirmed the importance of SHRSP alleles in the RNO3 congenic interval on pulse pressure variability and end-organ damage. These strains will allow interrogation of complex gene-gene and gene-environment interactions contributing to salt-sensitive hypertension and renal pathology in the SHRSP rat.
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Affiliation(s)
- H H Caline Koh-Tan
- Institute of Cardiovascular and Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, United Kingdom
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Kumarasamy S, Gopalakrishnan K, Toland EJ, Yerga-Woolwine S, Farms P, Morgan EE, Joe B. Refined mapping of blood pressure quantitative trait loci using congenic strains developed from two genetically hypertensive rat models. Hypertens Res 2011; 34:1263-70. [PMID: 21814219 DOI: 10.1038/hr.2011.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Previously linkage and substitution mapping were conducted between the Dahl Salt-sensitive (S) rat and the Spontaneously Hypertensive Rat (SHR) to address the hypothesis that genetic contributions to blood pressure (BP) in two genetically hypertensive rat strains are different. Among the BP quantitative trait loci (QTLs) detected, two are located on chromosome 9 within large genomic segments. The goal of the current study was to develop new iterations of congenic substrains, to further resolve both of these BP QTLs on chromosome 9 as independent congenic segments. A total of 10 new congenic substrains were developed and characterized. The newly developed congenic substrains S.SHR(9)x8Ax11A and S.SHR(9)x10Ax1, with introgressed segments of 2.05 and 6.14 Mb, represented the shortest genomic segments. Both of these congenic substrains, S.SHR(9)x8Ax11A and S.SHR(9)x10Ax1 lowered BP of the S rat by 56 mm Hg (P<0.001) and 15 mm Hg (P<0.039), respectively. The BP measurements were corroborated by radiotelemetry. Urinary protein excretion was significantly lowered by SHR alleles within S.SHR(9)x10Ax1 but not by S.SHR(9)x8Ax11A. The shorter of the two congenic segments, 2.05 Mb was further characterized and found to contain a single differentially expressed protein-coding gene, Tomoregulin-2 (Tmeff2). The protein expression of Tmeff2 was higher in the S rat compared with S.SHR(9)x8Ax11A, which also had lower cardiac hypertrophy as measured by echocardiography. Tmeff2 is known to be upregulated in patients from multiple cohorts with cardiac hypertrophy. Taken together, Tmeff2 can be prioritized as a candidate gene for hypertension and associated cardiac hypertrophy in both rats and in humans.
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Affiliation(s)
- Sivarajan Kumarasamy
- Physiological Genomics Laboratory, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
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Abstract
PURPOSE OF REVIEW Essential hypertension has long been considered to be primarily 'genetic,' though recent studies have only revealed minor contributions to blood pressure. Technology has advanced tremendously in the recent years, with much focus on DNA studies utilizing both candidate gene and genome-wide association studies. However, many new areas that need continued investigation have arisen. RECENT FINDINGS In addition to DNA studies, genetic studies are actively pursuing previously unexplored areas of potential variation, such as that which occurs posttranscriptionally in RNA and posttranslationally in protein structure. Advances have also been made in animal models and systems biology for large-scale integrative approaches. However, many other areas need continued investigation in the genetics of hypertension, including improved phenotyping and trait definition, gene-by-gene interactions (epistasis), and gene-by-environment interactions. 'Next generation' sequencing will assist researchers in performing more extensive genetic studies even more quickly, especially on unusual (rare) genetic variants. SUMMARY Hypertension appears to have many genetic contributions from each regulatory area ranging from DNA to RNA to protein to postprotein to interactive influences of the environment on genes. New technologies have enabled such research to advance in the recent years. However, for this complex trait of hypertension, continued efforts must progress in all of these areas as well as in increased modeling and sequencing, so that the knowledge may be united for a comprehensive understanding of this common disease, such that diagnosis and treatment options in hypertensive patients and those at risk are facilitated.
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Gopalakrishnan K, Morgan EE, Yerga-Woolwine S, Farms P, Kumarasamy S, Kalinoski A, Liu X, Wu J, Liu L, Joe B. Augmented rififylin is a risk factor linked to aberrant cardiomyocyte function, short-QT interval and hypertension. Hypertension 2011; 57:764-71. [PMID: 21357277 DOI: 10.1161/hypertensionaha.110.165803] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Using congenic strains of the Dahl salt-sensitive (S) rat introgressed with genomic segments from the normotensive Lewis rat, a blood pressure quantitative trait locus was previously mapped within 104 kb on chromosome 10. The goal of the current study was to conduct extensive phenotypic studies and to further fine-map this locus. At 14 weeks of age, the blood pressure of the congenic rats fed a low-salt diet was significantly higher by 47 mm Hg (P<0.001) compared with that of the S rat. A time-course study showed that the blood pressure effect was significant from very young ages of 50 to 52 days (13 mm Hg; P<0.01). The congenic strain implanted with electrocardiography transmitters demonstrated shorter-QT intervals and increased heart rate compared with S rats (P<0.01). The average survival of the congenic strain was shorter (134 days) compared with the S rat (175 days; P<0.0007). The critical region was narrowed to <42.5 kb containing 171 variants and a single gene, rififylin. Both the mRNA and protein levels of rififylin were significantly higher in the hearts of the congenic strain. Overexpression of rififylin is known to delay endocytic recycling. Endocytic recycling of fluorescently labeled holotransferrin from cardiomyocytes of the congenic strain was slower than that of S rats (P<0.01). Frequency of cardiomyocyte beats in the congenic strain (62±9 bpm) was significantly higher than that of the S rat (24±6 bpm; P<0.001). Taken together, our study provides evidence to suggest that early perturbations in endocytic recycling caused by the overexpression of Rffl is a novel physiological mechanism potentially underlying the development of hypertension.
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Affiliation(s)
- Kathirvel Gopalakrishnan
- Physiological Genomics Laboratory, Department of Physiology and Pharmacology, University of Toledo College of Medicine, 3000 Arlington Ave, Toledo, OH 43614-2598, USA
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Lynch AI, Tang W, Shi G, Devereux RB, Eckfeldt JH, Arnett DK. Epistatic effects of ACE I/D and AGT gene variants on left ventricular mass in hypertensive patients: the HyperGEN study. J Hum Hypertens 2011; 26:133-40. [PMID: 21248783 PMCID: PMC3775641 DOI: 10.1038/jhh.2010.131] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Identifying predictors of left ventricular hypertrophy has been an active study topic because of its association with cardiovascular morbidity and mortality. We examined the epistatic effect (gene-gene interaction) of two genes (angiotensin-converting enzyme (ACE) insertion/deletion (I/D); angiotensinogen (AGT) -6G-A, M235T, -20A-C) in the renin-angiotensin system on left ventricular mass (LVM) among hypertensive participants in the Hypertension Genetic Epidemiology Network study. Included were 2156 participants aged 20-87 years (60% women, 63% African American). We employed mixed linear regression models to assess main effects of four genetic variants on echocardigraphically determined LVM (indexed for height), and ACE-by-AGT epistatic effects. There was evidence that AGT -6G-A was associated with LVM among white participants: adjusted mean LVM (gm(-2.7)) increased with 'G' allele copy number ('AA':41.2, 'AG':42.3, 'GG':44.0; P=0.03). There was also evidence of an ACE I/D-by-AGT -20A-C epistatic effect among white participants (interaction P=0.03): among ACE 'DD' participants, AGT -20A-C 'C' allele carriers had lower mean LVM than 'AA' homozygotes ('DD/CC':39.2, 'DD/AC':39.9, 'DD/AA':43.9), with no similar significant effect among ACE 'I' allele carriers ('ID/CC':47.2, 'ID/AC':43.4, 'ID/AA':42.6; 'II/CC': NA, 'II/AC':41.3, 'II/AA':43.1). These findings indicate that renin-angiotensin system variants in at least two genes may interact to modulate LVM.
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Affiliation(s)
- A I Lynch
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
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Kumarasamy S, Gopalakrishnan K, Shafton A, Nixon J, Thangavel J, Farms P, Joe B. Mitochondrial polymorphisms in rat genetic models of hypertension. Mamm Genome 2010; 21:299-306. [PMID: 20443117 PMCID: PMC2890981 DOI: 10.1007/s00335-010-9259-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 04/09/2010] [Indexed: 12/04/2022]
Abstract
Hypertension is a complex trait that has been studied extensively for genetic contributions of the nuclear genome. We examined mitochondrial genomes of the hypertensive strains: the Dahl Salt-Sensitive (S) rat, the Spontaneously Hypertensive Rat (SHR), and the Albino Surgery (AS) rat, and the relatively normotensive strains: the Dahl Salt-Resistant (R) rat, the Milan Normotensive Strain (MNS), and the Lewis rat (LEW). These strains were used previously for linkage analysis for blood pressure (BP) in our laboratory. The results provide evidence to suggest that variations in the mitochondrial genome do not account for observed differences in blood pressure between the S and R rats. However, variants were detected among the mitochondrial genomes of the various hypertensive strains, S, SHR, and AS, and also among the normotensive strains R, MNS, and LEW. A total of 115, 114, 106, 106, and 16 variations in mtDNA were observed between the comparisons S versus LEW, S versus MNS, S versus SHR, S versus AS, and SHR versus AS, respectively. Among the 13 genes coding for proteins of the electron transport chain, 8 genes had nonsynonymous variations between S, LEW, MNS, SHR, and AS. The lack of any sequence variants between the mitochondrial genomes of S and R rats provides conclusive evidence that divergence in blood pressure between these two inbred strains is exclusively programmed through their nuclear genomes. The variations detected among the various hypertensive strains provides the basis to construct conplastic strains and further evaluate the effects of these variants on hypertension and associated phenotypes.
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Affiliation(s)
- Sivarajan Kumarasamy
- Physiological Genomics Laboratory, Department of Physiology and Pharmacology, University of Toledo College of Medicine, 3000 Arlington Avenue, Toledo, OH 43614-5804, USA
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