Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Am Heart Assoc ; 9(7): e014072, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32200719

RESUMO

Background Renal artery stenosis is a common cause of renal ischemia, contributing to the development of chronic kidney disease. To investigate the role of local CD40 expression in renal artery stenosis, Goldblatt 2-kidney 1-clip surgery was performed on hypertensive Dahl salt-sensitive rats (S rats) and genetically modified S rats in which CD40 function is abolished (Cd40mutant). Methods and Results Four weeks following the 2-kidney 1-clip procedure, Cd40mutant rats demonstrated significantly reduced blood pressure and renal fibrosis in the ischemic kidneys compared with S rat controls. Similarly, disruption of Cd40 resulted in reduced 24-hour urinary protein excretion in Cd40mutant rats versus S rat controls (46.2±1.9 versus 118.4±5.3 mg/24 h; P<0.01), as well as protection from oxidative stress, as indicated by increased paraoxonase activity in Cd40mutant rats versus S rat controls (P<0.01). Ischemic kidneys from Cd40mutant rats demonstrated a significant decrease in gene expression of the profibrotic mediator, plasminogen activator inhibitor-1 (P<0.05), and the proinflammatory mediators, C-C motif chemokine ligand 19 (P<0.01), C-X-C Motif Chemokine Ligand 9 (P<0.01), and interleukin-6 receptor (P<0.001), compared with S rat ischemic kidneys, as assessed by quantitative PCR assay. Reciprocal renal transplantation documented that CD40 exclusively expressed in the kidney contributes to ischemia-induced renal fibrosis. Furthermore, human CD40-knockout proximal tubule epithelial cells suggested that suppression of CD40 signaling significantly inhibited expression of proinflammatory and -fibrotic genes. Conclusions Taken together, our data suggest that activation of CD40 induces a significant proinflammatory and -fibrotic response and represents an attractive therapeutic target for treatment of ischemic renal disease.

2.
Physiol Genomics ; 52(1): 1-14, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31762410

RESUMO

Here we postulate that the heritability of complex disease traits previously ascribed solely to the inheritance of the nuclear and mitochondrial genomes is broadened to encompass a third component of the holobiome, the microbiome. To test this, we expanded on the selectively bred low capacity runner/high capacity runner (LCR/HCR) rat exercise model system into four distinct rat holobiont model frameworks including matched and mismatched host nuclear and mitochondrial genomes. Vertical selection of varying nuclear and mitochondrial genomes resulted in differential acquisition of the microbiome within each of these holobiont models. Polygenic disease risk of these novel models were assessed and subsequently correlated with patterns of acquisition and contributions of their microbiomes in controlled laboratory settings. Nuclear-mitochondrial-microbiotal interactions were not for exercise as a reporter of health, but significantly noted for increased adiposity, increased blood pressure, compromised cardiac function, and loss of long-term memory as reporters of disease susceptibility. These findings provide evidence for coselection of the microbiome with nuclear and mitochondrial genomes as an important feature impacting the heritability of complex diseases.

3.
Endocrinology ; 160(9): 2093-2100, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31294787

RESUMO

Regulated endocrine-specific protein-18 (RESP18), a novel 18-kDa protein, was first identified in neuroendocrine tissue. Subsequent studies showed that Resp18 is expressed in the adrenal medulla, brain, pancreas, pituitary, retina, stomach, superior cervical ganglion, testis, and thyroid and also circulates in the plasma. Resp18 has partial homology with the islet cell antigen 512, also known as protein tyrosine phosphatase, receptor type N (PTPRN), but does not have phosphatase activity. Resp18 might serve as an intracellular signal; however, its function is unclear. It is regulated by dopamine, glucocorticoids, and insulin. We recently reported that the targeted disruption of the Resp18 locus in Dahl salt-sensitive rats increased their blood pressure and caused renal injury. The aim of the present review was to provide a comprehensive summary of the reported data currently available, especially the expression and proposed organ-specific function of Resp18.


Assuntos
Proteínas do Tecido Nervoso/fisiologia , Animais , Doenças Cardiovasculares/prevenção & controle , Dopamina/fisiologia , Gastrinas/fisiologia , Glucocorticoides/fisiologia , Humanos , Sistema Hipotálamo-Hipofisário/fisiologia , Insulina/fisiologia , Proteínas do Tecido Nervoso/química , Doença de Parkinson/etiologia
4.
Biochem Pharmacol ; 168: 71-81, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31228465

RESUMO

Iron is essential for many biological functions, including being a cofactor for enzymes involved in cell proliferation. In line, it has been shown that cancer cells can perturb their iron metabolism towards retaining an abundant iron supply for growth and survival. Accordingly, it has been suggested that iron deprivation through the use of iron chelators could attenuate cancer progression. While they have exhibited anti-tumor properties in vitro, the current therapeutic iron chelators are inadequate due to their low efficacy. Therefore, we investigated whether the bacterial catecholate-type siderophore, enterobactin (Ent), could be used as a potent anti-cancer agent given its strong iron chelation property. We demonstrated that iron-free Ent can exert cytotoxic effects specifically towards monocyte-related tumor cell lines (RAW264.7 and J774A.1), but not primary cells, i.e. bone marrow-derived macrophages (BMDMs), through two mechanisms. First, we observed that RAW264.7 and J774A.1 cells preserve a bountiful intracellular labile iron pool (LIP), whose homeostasis can be disrupted by Ent. This may be due, in part, to the lower levels of lipocalin 2 (Lcn2; an Ent-binding protein) in these cell lines, whereas the higher levels of Lcn2 in BMDMs could prevent Ent from hindering their LIP. Secondly, we observed that Ent could dose-dependently impede reactive oxygen species (ROS) generation in the mitochondria. Such disruption in LIP balance and mitochondrial function may in turn promote cancer cell apoptosis. Collectively, our study highlights Ent as an anti-cancer siderophore, which can be exploited as an unique agent for cancer therapy.

5.
Biochem Biophys Res Commun ; 513(3): 760-765, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-30992131

RESUMO

Several independent genome-wide association studies (GWAS) have indicated that calcium (Ca2+) voltage-gated channel auxiliary subunit beta 2 (CACNB2) an L-type Ca2+ channel (LTCC) associated protein has strong association with hypertension. However, the molecular mechanism of CACNB2 and its role in the pathophysiology of hypertension is not clear. To address this knowledge gap, we utilized in vitro and in vivo approaches using HEK293 cells and genetically hypertensive, Dahl Salt-Sensitive (SS) rats. We demonstrated that CACNB2 over-expression in HEK293 cells triggers cell proliferation via an up-regulation of the RAS-MAPK pathway compared to non-transfected cells. These effects were likely independent of LTCC activity as treatment with nifedipine, a well-known LTCC blocker, in CACNB2 overexpressing cells failed to inhibit the RAS-MAPK pathway gene expressions or show an effect on apoptosis marker gene expression. Furthermore, the expression level of CACNB2 was up-regulated in the high salt (HS) diet fed SS rat kidneys compared to low salt diet (LS) fed group. Similar to our in vitro observation the RAS-MAPK mRNA levels were increased in HS fed SS rat kidneys, compared to LS fed group. Collectively, our data suggest that CACNB2 is associated with the increase in RAS-MAPK gene expressions and lead us to speculate that in addition to its role in regulating LTCC α1-subunit trafficking, CACNB2 might lead to aberrant RAS activation, which is one of the key cascade associated with hypertension.

6.
J Enzyme Inhib Med Chem ; 34(1): 863-876, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30915862

RESUMO

The present study describes the synthesis of a series of 22 chalcone analogs. These compounds were evaluated as potential human MAO-A and MAO-B inhibitors. The compounds showed varied selectivity against the two isoforms. The IC50 values were found to be in the micromolar to submicromolar range. The Ki values of compound 16 were determined to be 0.047 and 0.020 µM for the inhibition of MAO-A and MAO-B, respectively. Dialysis of enzyme-inhibitor mixtures indicated a reversible competitive mode of inhibition. Most of the synthesized chalcone analogs showed a better selectivity toward MAO-B. However, introducing of 2,4,6-trimethoxy substituents on ring B shifted the selectivity toward MAO-A. In addition, we investigated the molecular mechanism of MAO-B inhibition by selected chalcone analogs. Our results revealed that these selected chalcone analogs increased dopamine levels in the rat hepatoma (H4IIE) cells and decreased the relative mRNA expression of the MAO-B enzyme.


Assuntos
Chalcona/farmacologia , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/metabolismo , Chalcona/síntese química , Chalcona/química , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores da Monoaminoxidase/síntese química , Inibidores da Monoaminoxidase/química , Relação Estrutura-Atividade
7.
Steroids ; 141: 63-69, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30481528

RESUMO

Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP-TFII) is an orphan member of the nuclear receptor family of transcriptional regulators. Although hormonal activation of COUP-TFII has not yet been identified, rodent genetic models have uncovered vital and diverse roles for COUP-TFII in biological processes. These include control of cardiac function and angiogenesis, reproduction, neuronal development, cell fate and organogenesis. Recently, an emerging body of evidence has demonstrated COUP-TFII involvement in various metabolic systems such as adipogenesis, lipid metabolism, hepatic gluconeogenesis, insulin secretion, and regulation of blood pressure. The potential relevance of these observations to human pathology has been corroborated by the identification of single nucleotide polymorphism in the human COUP-TFII promoter controlling insulin sensitivity. Of particular interest to metabolism is the ability of COUP-TFII to interact with the Glucocorticoid Receptor (GR). This interaction is known to control gluconeogenesis, principally through direct binding of COUP-TFII/GR complexes to the promoters of gluconeogenic enzyme genes. However, it is likely that this interaction is critical to other metabolic processes, since GR, like COUP-TFII, is an essential regulator of adipogenesis, insulin sensitivity, and blood pressure. This review will highlight these unique roles of COUP-TFII in metabolic gene regulation.


Assuntos
Fator II de Transcrição COUP/metabolismo , Animais , Fator II de Transcrição COUP/genética , Regulação da Expressão Gênica , Humanos , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo
8.
Int J Mol Sci ; 19(7)2018 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-30037072

RESUMO

Non-coding RNAs are important regulators of protein-coding genes. The current study characterized an antisense long non-coding RNA, ATP1A1-AS1, which is located on the opposite strand of the Na/K-ATPase α1 gene. Our results show that four splice variants are expressed in human adult kidney cells (HK2 cells) and embryonic kidney cells (HEK293 cells). These variants can be detected in both cytosol and nuclear fractions. We also found that the inhibition of DNA methylation has a differential effect on the expression of ATP1A1-AS1 and its sense gene. To investigate the physiological role of this antisense gene, we overexpressed the ATP1A1-AS1 transcripts, and examined their effect on Na/K-ATPase expression and related signaling function in human kidney cells. The results showed that overexpression of the ATP1A1-AS1-203 transcript in HK2 cells reduced the Na/K-ATPase α1 (ATP1A1) gene expression by approximately 20% (p < 0.05), while reducing the Na/K-ATPase α1 protein synthesis by approximately 22% (p < 0.05). Importantly, overexpression of the antisense RNA transcript attenuated ouabain-induced Src activation in HK2 cells. It also inhibited the cell proliferation and potentiated ouabain-induced cell death. These results demonstrate that the ATP1A1-AS1 gene is a moderate negative regulator of Na/K-ATPase α1, and can modulate Na/K-ATPase-related signaling pathways in human kidney cells.


Assuntos
Rim/metabolismo , RNA Antissenso/metabolismo , RNA Longo não Codificante/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Western Blotting , Linhagem Celular , Proliferação de Células/genética , Proliferação de Células/fisiologia , Epigênese Genética/genética , Epigênese Genética/fisiologia , Células HEK293 , Fator 3-alfa Nuclear de Hepatócito/genética , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Humanos , RNA Antissenso/genética , RNA Longo não Codificante/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , ATPase Trocadora de Sódio-Potássio/genética
9.
Physiol Genomics ; 50(5): 369-375, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29570433

RESUMO

Hypertension is a classic example of a complex polygenic trait, impacted by quantitative trait loci (QTL) containing candidate genes thought to be responsible for blood pressure (BP) control in mammals. One such mapped locus is on rat chromosome 9, wherein the proof for a positional candidate gene, regulated endocrine-specific protein-18 ( Resp18) is currently inadequate. To ascertain the status of Resp18 as a BP QTL, a custom targeted gene disruption model of Resp18 was developed on the Dahl salt-sensitive (SS) background. As a result of this zinc-finger nuclease (ZFN)-mediated disruption, a 7 bp deletion occurred within exon 3 of the Resp18 locus. Targeted disruption of Resp18 gene locus in SS rats decreases its gene expression in both heart and kidney tissues regardless of their dietary salt level. Under a high-salt dietary regimen, both systolic and diastolic BP of Resp18mutant rats were significantly increased compared with SS rats. Resp18mutant rats demonstrated increased renal damage, as evidenced by higher proteinuria and increased renal fibrosis compared with SS rats. Furthermore, under a high-salt diet regimen, the mean survival time of Resp18mutant rats was significantly reduced compared with SS rats. These findings serve as evidence in support of Resp18 as a gene associated with the development of hypertension and renal disease.


Assuntos
Hipertensão/genética , Nefropatias/genética , Proteínas do Tecido Nervoso/genética , Cloreto de Sódio na Dieta/efeitos adversos , Sequência de Aminoácidos , Animais , Sequência de Bases , Pressão Sanguínea/genética , Expressão Gênica/efeitos dos fármacos , Marcação de Genes/métodos , Hipertensão/etiologia , Estimativa de Kaplan-Meier , Nefropatias/etiologia , Locos de Características Quantitativas/genética , Ratos Endogâmicos Dahl , Ratos Mutantes , Deleção de Sequência , Cloreto de Sódio na Dieta/administração & dosagem
10.
Sci Rep ; 7: 39867, 2017 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-28051144

RESUMO

In previous studies using mice with macrophage-specific loss of TRPC3 we found a significant, selective effect of TRPC3 on the biology of M1, or inflammatory macrophages. Whereas activation of some components of the unfolded protein response and the pro-apoptotic mediators CamkII and Stat1 was impaired in Trpc3-deficient M1 cells, gathering insight about other molecular signatures within macrophages that might be affected by Trpc3 expression requires an alternative approach. In the present study we conducted RNA-seq analysis to interrogate the transcriptome of M1 macrophages derived from mice with macrophage-specific loss of TRPC3 and their littermate controls. We identified 160 significantly differentially expressed genes between the two groups, of which 62 were upregulated and 98 downregulated in control vs. Trpc3-deficient M1 macrophages. Gene ontology analysis revealed enrichment in processes associated to cellular movement and lipid signaling, whereas the enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways included networks for calcium signaling and cell adhesion molecules, among others. This is the first deep transcriptomic analysis of macrophages in the context of Trpc3 deficiency and the data presented constitutes a unique resource to further explore functions of TRPC3 in macrophage biology.


Assuntos
Perfilação da Expressão Gênica , Macrófagos/metabolismo , Canais de Cátion TRPC/genética , Animais , Células da Medula Óssea/citologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2/farmacologia , Regulação para Baixo , Macrófagos/citologia , Camundongos , Camundongos Knockout , Netrina-1/farmacologia , Canais de Cátion TRPC/deficiência , Transcriptoma , Regulação para Cima
11.
Kidney Int ; 91(2): 365-374, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27692815

RESUMO

High blood pressure is a common cause of chronic kidney disease. Because CD40, a member of the tumor necrosis factor receptor family, has been linked to the progression of kidney disease in ischemic nephropathy, we studied the role of Cd40 in the development of hypertensive renal disease. The Cd40 gene was mutated in the Dahl S genetically hypertensive rat with renal disease by targeted-gene disruption using zinc-finger nuclease technology. These rats were then given low (0.3%) and high (2%) salt diets and compared. The resultant Cd40 mutants had significantly reduced levels of both urinary protein excretion (41.8 ± 3.1 mg/24 h vs. 103.7 ± 4.3 mg/24 h) and plasma creatinine (0.36 ± 0.05 mg/dl vs. 1.15 ± 0.19 mg/dl), with significantly higher creatinine clearance compared with the control S rats (3.04 ± 0.48 ml/min vs. 0.93 ± 0.15 ml/min), indicating renoprotection was conferred by mutation of the Cd40 locus. Furthermore, the Cd40 mutants had a significant attenuation in renal fibrosis, which persisted on the high salt diet. However, there was no difference in systolic blood pressure between the control and Cd40 mutant rats. Thus, these data serve as the first evidence for a direct link between Cd40 and hypertensive nephropathy. Hence, renal fibrosis is one of the underlying mechanisms by which Cd40 plays a crucial role in the development of hypertensive renal disease.


Assuntos
Pressão Sanguínea/genética , Antígenos CD40/genética , Hipertensão/genética , Nefropatias/prevenção & controle , Rim/metabolismo , Mutação , Proteinúria/prevenção & controle , Animais , Linfócitos B/metabolismo , Antígenos CD40/metabolismo , Movimento Celular , Creatinina/sangue , Dieta Hipossódica , Modelos Animais de Doenças , Fibrose , Predisposição Genética para Doença , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Rim/patologia , Rim/fisiopatologia , Nefropatias/genética , Nefropatias/metabolismo , Nefropatias/fisiopatologia , Ativação Linfocitária , Fenótipo , Fosforilação , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Proteinúria/genética , Proteinúria/metabolismo , Proteinúria/fisiopatologia , Ratos Endogâmicos Dahl , Ratos Mutantes , Eliminação Renal , Cloreto de Sódio na Dieta , Linfócitos T/metabolismo , Fatores de Tempo , Quinases da Família src/metabolismo
12.
Physiol Genomics ; 48(6): 409-19, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27113531

RESUMO

Through linkage analysis of the Dahl salt-sensitive (S) rat and the spontaneously hypertensive rat (SHR), a blood pressure (BP) quantitative trait locus (QTL) was previously located on rat chromosome 9. Subsequent substitution mapping studies of this QTL revealed multiple BP QTLs within the originally identified logarithm of odds plot by linkage analysis. The focus of this study was on a 14.39 Mb region, the distal portion of which remained unmapped in our previous studies. High-resolution substitution mapping for a BP QTL in the setting of a high-salt diet indicated that an SHR-derived congenic segment of 787.9 kb containing the gene secreted phosphoprotein-2 (Spp2) lowered BP and urinary protein excretion. A nonsynonymous G/T polymorphism in the Spp2 gene was detected between the S and S.SHR congenic rats. A survey of 45 strains showed that the T allele was rare, being detected only in some substrains of SHR and WKY. Protein modeling prediction through SWISSPROT indicated that the predicted protein product of this variant was significantly altered. Importantly, in addition to improved cardiovascular and renal function, high salt-fed congenic animals carrying the SHR T variant of Spp2 had significantly lower bone mass and altered bone microarchitecture. Total bone volume and volume of trabecular bone, cortical thickness, and degree of mineralization of cortical bone were all significantly reduced in congenic rats. Our study points to opposing effects of a congenic segment containing the prioritized candidate gene Spp2 on BP and bone mass.


Assuntos
Pressão Sanguínea/genética , Osso e Ossos/metabolismo , Cromossomos Humanos Par 9/genética , Fosfoproteínas/genética , Locos de Características Quantitativas/genética , Alelos , Animais , Animais Congênicos/genética , Mapeamento Cromossômico/métodos , Ligação Genética/genética , Humanos , Hipertensão/genética , Masculino , Ratos , Ratos Endogâmicos Dahl , Ratos Endogâmicos SHR/genética , Ratos Endogâmicos WKY , Cloreto de Sódio na Dieta/administração & dosagem
13.
J Mol Cell Cardiol ; 88: 101-10, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26388265

RESUMO

The transcriptional regulation of pathological cardiac hypertrophy involves the interplay of transcription factors and chromatin remodeling enzymes. The Microphthalmia-Associated Transcription Factor (MITF) is highly expressed in cardiomyocytes and is required for cardiac hypertrophy. However, the transcriptional mechanisms by which MITF promotes cardiac hypertrophy have not been elucidated. In this study, we tested the hypothesis that MITF promotes cardiac hypertrophy by activating transcription of pro-hypertrophy genes through interactions with the SWI/SNF chromatin remodeling complex. In an in vivo model of cardiac hypertrophy, expression of MITF and the BRG1 subunit of the SWI/SNF complex increased coordinately in response to pressure overload. Expression of MITF and BRG1 also increased in vitro when cardiomyocytes were stimulated with angiotensin II or a ß-adrenergic agonist. Both MITF and BRG1 were required to increase cardiomyocyte size and activate expression of hypertrophy markers in response to ß-adrenergic stimulation. We detected physical interactions between MITF and BRG1 in cardiomyocytes and found that they cooperate to regulate expression of a pro-hypertrophic transcription factor, GATA4. Our data show that MITF binds to the E box element in the GATA4 promoter and facilitates recruitment of BRG1. This is associated with enhanced expression of the GATA4 gene as evidenced by increased Histone3 lysine4 tri-methylation (H3K4me3) on the GATA4 promoter. Thus, in hypertrophic cardiomyoctes, MITF is a key transcriptional activator of a pro-hypertrophic gene, GATA4, and this regulation is dependent upon the BRG1 component of the SWI/SNF complex.


Assuntos
Cardiomegalia/genética , DNA Helicases/genética , Fator de Transcrição GATA4/genética , Fator de Transcrição Associado à Microftalmia/genética , Miócitos Cardíacos/metabolismo , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Angiotensina II/farmacologia , Animais , Aorta/cirurgia , Sequência de Bases , Sítios de Ligação , Cardiomegalia/etiologia , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Linhagem Celular , Constrição Patológica/complicações , Constrição Patológica/cirurgia , DNA Helicases/metabolismo , Fator de Transcrição GATA4/metabolismo , Regulação da Expressão Gênica , Isoproterenol/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator de Transcrição Associado à Microftalmia/metabolismo , Dados de Sequência Molecular , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Proteínas Nucleares/metabolismo , Cultura Primária de Células , Ligação Proteica , Ratos , Transdução de Sinais , Fatores de Transcrição/metabolismo , Transcrição Genética
14.
Nat Commun ; 6: 6252, 2015 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-25687237

RESUMO

Genome-wide association studies (GWAS) have prioritized a transcription factor, nuclear receptor 2 family 2 (NR2F2), as being associated with essential hypertension in humans. Here we provide evidence that validates this association and indicates that Nr2f2 is a genetic determinant of blood pressure (BP). Using the zinc-finger nuclease technology, the generation of a targeted Nr2f2-edited rat model is reported. The resulting gene-edited rats have a 15 bp deletion in exon 2 leading to a five-amino-acid deletion in the hinge region of the mutant Nr2f2 protein. Both systolic and diastolic blood pressures of the Nr2f2(mutant) rats are significantly lower than controls. Because the hinge region of Nr2f2 is required for interaction with Friend of Gata2 (Fog2), protein-protein interaction is examined. Interaction of Nr2f2(mutant) protein with Fog2 is greater than that with the wild-type Nr2f2, indicating that the extent of interaction between these two transcription factors critically influences BP.


Assuntos
Pressão Sanguínea/genética , Fator II de Transcrição COUP/genética , Fator II de Transcrição COUP/fisiologia , Hipertensão/genética , Mutação , Animais , Células COS , Proteínas de Ligação a DNA/metabolismo , Diástole , Modelos Animais de Doenças , Hipertensão Essencial , Éxons , Feminino , Deleção de Genes , Estudo de Associação Genômica Ampla , Masculino , Mapeamento de Interação de Proteínas , Ratos , Sístole , Fatores de Transcrição/metabolismo , Dedos de Zinco
15.
Hypertens Res ; 38(1): 61-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25231251

RESUMO

Genetic dissection of blood pressure (BP) quantitative trait loci (QTLs) in rats has facilitated the fine-mapping of regions linked to the inheritance of hypertension. The goal of the current study was to further fine-map one such genomic region on rat chromosome 1 (BPQTL1b1), the homologous region of which on human chromosome 15 harbors BP QTLs, as reported by four independent studies. Of the six substrains constructed and studied, the systolic BP of two of the congenic strains were significantly lower by 36 and 27 mm Hg than that of the salt-sensitive (S) rat (P < 0.0001, P = 0.0003, respectively). The congenic segments of these two strains overlapped between 135.12 and 138.78 Mb and contained eight genes and two predicted miRNAs. None of the annotations had variants within expressed sequences. These data taken together with the previous localization resolved QTL1b1 with a 70% improvement from the original 7.39 Mb to the current 2.247 Mb interval. Furthermore, the systolic BP of one of the congenic substrains was significantly higher by 20 mm Hg (P < 0.0001) than the BP of the S rat. The limits of this newly identified QTL with a BP increasing effect (QTL1b1a) were between 134.12 and 135.76 Mb, spanning 1.64 Mb, containing two protein-coding genes, Mctp2 and Rgma, and a predicted miRNA. There were four synonymous variants within Mctp2. These data provide evidence for two independent BP QTLs with opposing BP effects within the previously identified BP QTL1b1 region. Additionally, these findings illustrate the complexity underlying the genetic mechanisms of BP regulation, wherein inherited elements beyond protein-coding sequences or known regulatory regions could be operational.


Assuntos
Pressão Sanguínea/genética , Hipertensão/genética , Locos de Características Quantitativas , Animais , Mapeamento Cromossômico , Cromossomos Humanos Par 15 , Humanos , Masculino , Ratos Endogâmicos Dahl , Ratos Endogâmicos Lew
16.
Hypertension ; 65(1): 200-10, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25385761

RESUMO

Long noncoding RNAs (lncRNAs) are an emerging class of genomic regulatory molecules reported in various species. In the rat, which is one of the major mammalian model organisms, discovery of lncRNAs on a genome-wide scale is lagging. Renal lncRNA sequencing and lncRNA transcriptome analysis were conducted in 3 rat strains that are widely used in cardiovascular and renal research: the Dahl salt-sensitive rat, the spontaneously hypertensive rat, and the Dahl salt-resistant rat. Through the RNA sequencing approach, 3273 transcripts were identified as rat lncRNAs. A majority of lncRNAs were without predicted target genes. Differential expression of 273 and 749 lncRNAs was detected between Dahl salt-sensitive versus Dahl salt-resistant and Dahl salt-sensitive versus spontaneously hypertensive rat comparisons, respectively. To couple the observed differential expression of lncRNAs with the status of mRNAs, an mRNA transcriptome analysis was conducted. Several cis mRNA genes were coregulated with lncRNAs. Of these, the protein expression status of 4 target genes, Asb3, Chac2, Pex11b, and Sp5, were differentially expressed between the relevant strain comparisons, thereby suggesting that the differentially expressed lncRNAs associated with these genes are candidate genetic determinants of blood pressure. This study serves as a first-generation catalog of rat lncRNAs and illustrates the prioritization of lncRNAs as candidates for complex polygenic traits.


Assuntos
Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/genética , Estudo de Associação Genômica Ampla/métodos , Nefropatias/genética , RNA Longo não Codificante/genética , Animais , Doenças Cardiovasculares/diagnóstico , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Immunoblotting , Nefropatias/diagnóstico , Análise em Microsséries , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley
17.
Physiol Genomics ; 45(16): 729-36, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23757393

RESUMO

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.


Assuntos
Pressão Sanguínea/fisiologia , Epistasia Genética/fisiologia , Ensaios de Triagem em Larga Escala/métodos , Hipertensão/fisiopatologia , Animais , Pressão Sanguínea/genética , Epistasia Genética/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Genótipo , Hipertensão/genética , Locos de Características Quantitativas/genética , Ratos
18.
Am J Physiol Heart Circ Physiol ; 304(1): H22-32, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23125210

RESUMO

Because of the lack of appropriate animal models, the potentially causal contributions of inherited mitochondrial genomic factors to complex traits are less well studied compared with inherited nuclear genomic factors. We previously detected variations between the mitochondrial DNA (mtDNA) of the Dahl salt-sensitive (S) rat and the spontaneously hypertensive rat (SHR). Specifically, multiple variations were detected in mitochondrial genes coding for subunits of proteins essential for electron transport, in mitochondrial reactive oxygen species production, and within the D-loop region. To evaluate the effects of these mtDNA variations in the absence of the corresponding nuclear genomic factors as confounding variables, novel reciprocal strains of S and SHR were constructed and characterized. When compared with that of the S rat, the heart tissue from the S.SHR(mt) conplastic strain wherein the mtDNA of the S rat was substituted with that of the SHR had a significant increase in mtDNA copy number and decrease in mitochondrial reactive oxygen species production. A corresponding increase in aerobic treadmill running capacity and a significant increase in survival that was not related to changes in blood pressure were observed in the S.SHR(mt) rats compared with the S rat. The reciprocal SHR.S(mt) rats did not differ from the SHR in any phenotype tested, suggesting lower penetrance of the S mtDNA on the nuclear genomic background of the SHR. These novel conplastic strains serve as invaluable tools to further dissect the relationship between heart function, aerobic fitness, cardiovascular disease progression, and mortality.


Assuntos
DNA Mitocondrial/genética , Mitocôndrias Cardíacas/metabolismo , Ratos Endogâmicos Dahl/genética , Ratos Endogâmicos SHR/genética , Animais , Pressão Sanguínea/genética , Peso Corporal/genética , Metabolismo Energético/genética , Dosagem de Genes , Regulação Enzimológica da Expressão Gênica , Genótipo , Hibridização Genética , Longevidade/genética , Mitocôndrias Cardíacas/enzimologia , Dilatação Mitocondrial/genética , Renovação Mitocondrial/genética , Estresse Oxidativo/genética , Penetrância , Fenótipo , Ratos , Espécies Reativas de Oxigênio/metabolismo
19.
Proc Natl Acad Sci U S A ; 109(50): 20555-9, 2012 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-23185005

RESUMO

A disintegrin-like metalloproteinase with thrombospondin motifs-16 (Adamts16) is an important candidate gene for hypertension. The goal of the present study was to further assess the candidacy of Adamts16 by targeted disruption of this gene in a rat genetic model of hypertension. A rat model was generated by manipulating the genome of the Dahl Salt-sensitive (S) rat using zinc-finger nucleases, wherein the mutant rat had a 17 bp deletion in the first exon of Adamts16, introducing a stop codon in the transcript. Systolic blood pressure (BP) of the homozygous Adamts16(mutant) rats was lower by 36 mmHg compared with the BP of the S rats. The Adamts16(mutant) rats exhibited significantly lower aortic pulse wave velocity and vascular media thickness compared with S rats. Scanning electron and fluorescence microscopic studies indicated that the mechanosensory cilia of vascular endothelial cells from the Adamts16(mutant) rats were longer than that of the S rats. Furthermore, Adamts16(mutant) rats showed splitting and thickening of glomerular capillaries and had a longer survival rate, compared with the S rats. Taken together, these physiological observations functionally link Adamts16 to BP regulation and suggest the vasculature as the potential site of action of Adamts16 to lower BP.


Assuntos
Proteínas ADAM/genética , Proteínas ADAM/fisiologia , Hipertensão/genética , Hipertensão/fisiopatologia , Proteínas ADAM/deficiência , Animais , Sequência de Bases , Pressão Sanguínea/genética , Pressão Sanguínea/fisiologia , Vasos Sanguíneos/patologia , Vasos Sanguíneos/fisiopatologia , DNA/genética , Modelos Animais de Doenças , Feminino , Marcação de Genes , Heterozigoto , Homozigoto , Hipertensão/patologia , Glomérulos Renais/irrigação sanguínea , Glomérulos Renais/patologia , Masculino , Proteínas Mutantes/genética , Proteínas Mutantes/fisiologia , Análise de Onda de Pulso , Ratos , Ratos Endogâmicos Dahl , Ratos Mutantes , Deleção de Sequência , Túnica Média/patologia
20.
Front Genet ; 3: 138, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22891072

RESUMO

Cell surface proteins are internalized into the cell through endocytosis and either degraded within lysosomes or recycled back to the plasma membrane. While perturbations in endosomal internalization are known to modulate renal function, it is not known whether similar alterations in recycling affect renal function. Rififylin is a known regulator of endocytic recycling with E3 ubiquitin protein ligase activity. In this study, using two genetically similar strains, the Dahl Salt-sensitive rat and an S.LEW congenic strain, which had allelic variants within a < 330 kb segment containing rififylin, we tested the hypothesis that alterations in endosomal recycling affect renal function. The congenic strain had 1.59-fold higher renal expression of rififylin. Transcriptome analysis indicated that components of both endocytosis and recycling were upregulated in the congenic strain. Transcription of Atp1a1 and cell surface content of the protein product of Atp1a1, the alpha subunit of Na(+)K(+)ATPase were increased in the proximal tubules from the congenic strain. Because rififylin does not directly regulate endocytosis and it is also a differentially expressed gene within the congenic segment, we reasoned that the observed alterations in the transcriptome of the congenic strain constitute a feedback response to the primary functional alteration of recycling caused by rififylin. To test this, recycling of transferrin was studied in isolated proximal tubules. Recycling was significantly delayed within isolated proximal tubules of the congenic strain, which also had a higher level of polyubiquitinated proteins and proteinuria compared with S. These data provide evidence to suggest that delayed endosomal recycling caused by excess of rififylin indirectly affects endocytosis, enhances intracellular protein polyubiquitination and contributes to proteinuria.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA