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2.
Hypertension ; : HYPERTENSIONAHA12014830, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32450738

RESUMO

Alterations of diurnal rhythms of blood pressure (BP) and reshaping of gut microbiota are both independently associated with hypertension. However, the relationships between biorhythms of BP and gut microbial composition are unknown. We hypothesized that diurnal timing-associated alterations of microbial compositions are synchronous with diurnal rhythmicity, dip in BP, and renal function. To test this hypothesis, Dahl salt-sensitive (S) rats on low- and high-salt diets were examined for time of day effects on gut microbiota, BP, and indicators of renal damage. Major shifts in night and day patterns of specific groups of microbiota were observed between the dark (active) and light (rest) phases, which correlated with diurnal rhythmicity of BP. The diurnal abundance of Firmicutes, Bacteroidetes, and Actinobacteria were independently associated with BP. Discrete bacterial taxa were observed to correlate independently or interactively with one or more of the following 3 factors: (1) BP rhythm, (2) dietary salt, and (3) dip in BP. Phylogenetic Investigation of Communities revealed diurnal timing effects on microbial pathways, characterized by upregulated biosynthetic processes during the active phase of host, and upregulated degradation pathways of metabolites in the resting phase. Additional metagenomics functional pathways with rhythm variations were noted for aromatic amino acid metabolism and taurine metabolism. These diurnal timing dependent changes in microbiota, their functional pathways, and BP dip were associated with concerted effects of the levels of renal lipocalin 2 and kidney injury molecule-1 expression. These data provide evidence for a firm and concerted diurnal timing effects of BP, renal damage, and select microbial communities.

3.
Dis Model Mech ; 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32238420

RESUMO

Red blood cell distribution width (RDW) is a measurement of the variation in size and volume of red blood cells (RBCs). Increased RDW, indicating a high heterogeneity of RBCs, is prominently associated with a variety of illnesses, especially cardiovascular diseases. However, the significance of this association to the onset and progression of cardiovascular and renal diseases is unknown. We hypothesized that a genetic predisposition for increased RDW is an early risk factor for cardiovascular and renal comorbidities. Since there is no known animal model of increased RDW, we examined a CRISPR/Cas9 gene-edited rat model (RfflTD) which presented with features of hematologic abnormalities as well as severe cardiac and renal comorbidities. A mass-spectrometry based quantitative proteomic analysis indicated anemia of these rats presented with significant downregulation of hemoglobin and haptoglobin. Decreased hemoglobin and increased RDW were further observed in RfflTD through complete blood count. Next, a systematic temporal assessment detected an early increased RDW in RfflTD, which was prior to the development of other comorbidities. The primary mutation of RfflTD is a 50bp deletion in a non-coding region, whereby, our study has serendipitously identified this locus as a novel quantitative trait locus (QTL) for RDW. To our knowledge, our study is the first to experimentally pinpoint a QTL for RDW and provides a novel genetic rat model mimicking the clinical association of increased RDW with poor cardio-renal outcomes.

4.
J Pediatr Surg ; 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-32037220

RESUMO

BACKGROUND: The inguinoscrotal stage of testicular descent is characterized by an increase in cell density and collagen fibers as the gubernaculum undergoes cell division and increases Extracellular Matrix (ECM) activity. Rats that lack the enzyme Adamts16, a known ECM proteinase, develop cryptorchidism postnatally and are infertile. Therefore, this study aims to investigate the link between the Adamts16 enzyme and congenital undescended testes (UDT) in Adamts16 knockout (KO) rats during postnatal development. METHODS: Formalin-fixed specimens of Wild-Type, Adamts16 heterozygous and Adamts16 homozygous KO rats post birth were sectioned and used for standard H&E histology and Masson's trichrome staining. A quantitative analysis on image J was performed to determine the intensity of collagen fibers within the inguinoscrotal fat pad (IFP) (n = 3 age/genotype). RESULTS: The migration of the gubernaculum within the Adamts16 heterozygous and Adamts16 KO rat was considerably disrupted. Furthermore, the Masson's trichrome staining demonstrated a significant increase in collagen fibers around the gubernaculum of rats that lacked Adamts16 enzyme at day 8. CONCLUSION: This study reports a failure of gubernacular migration leading to UDT in Adamts16 KO rats during development, suggesting that the expression of Adamts16 gene is critical for normal gubernacular migration through the breakdown of collagen fibers within the IFP.

5.
J Am Heart Assoc ; 9(2): e014373, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31928175

RESUMO

Background Pediatric hypertension is recognized as an emerging global health concern. Although new guidelines are developed for facilitating clinical management, the reasons for the prevalence of hypertension in children remain unknown. Genetics and environmental factors do not fully account for the growing incidence of pediatric hypertension. Because stable bacterial flora in early life are linked with health outcomes later in life, we hypothesized that reshaping of gut microbiota in early life affects blood pressure (BP) of pediatric subjects. Methods and Results To test this hypothesis, we administered amoxicillin, the most commonly prescribed pediatric antibiotic, to alter gut microbiota of young, genetically hypertensive rats (study 1) and dams during gestation and lactation (study 2) and recorded their BP. Reshaping of microbiota with reductions in Firmicutes/Bacteriodetes ratio were observed. Amoxicillin treated rats had lower BP compared with untreated rats. In young rats treated with amoxicillin, the lowering effect on BP persisted even after antibiotics were discontinued. Similarly, offspring from dams treated with amoxicillin showed lower systolic BP compared with control rats. Remarkably, in all cases, a decrease in BP was associated with lowering of Veillonellaceae, which are succinate-producing bacteria. Elevated plasma succinate is reported in hypertension. Accordingly, serum succinate was measured and found lower in animals treated with amoxicillin. Conclusions Our results demonstrate a direct correlation between succinate-producing gut microbiota and early development of hypertension and indicate that reshaping gut microbiota, especially by depleting succinate-producing microbiota early in life, may have long-term benefits for hypertension-prone individuals.

6.
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.

7.
PLoS One ; 14(8): e0221658, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31442284

RESUMO

Fine-mapping of regions linked to the inheritance of hypertension is accomplished by genetic dissection of blood pressure quantitative trait loci (BP QTLs) in rats. The goal of the current study was to further fine-map two genomic regions on rat chromosome 1 with opposing blood pressure effects (BP QTL1b1 and BP QTL1b1a), the homologous region of which on human chromosome 15 harbors BP QTLs. Two new substrains were constructed and studied from the previously reported BP QTL1b1, one having significantly lower systolic BP by 17 mmHg than that of the salt-sensitive (S) rat (P = 0.007). The new limits of BP QTL1b1 were between 134.09 Mb and 135.40 Mb with a 43% improvement from the previous 2.31 Mb to the current 1.31 Mb interval containing 4 protein-coding genes (Rgma, Chd2, Fam174b, and St8sia2), 2 predicted miRNAs, and 4 lncRNAs. One new substrain was constructed and studied from the previously reported BPQTL1b1a having a significantly higher systolic BP by 22 mmHg (P = 0.006) than that of the S rat. The new limits of BPQTL1b1a were between 133.53 Mb and 134.52 Mb with a 32% improvement from the previous1.45 Mb to the current 990.21 Kb interval containing 1 protein-coding gene, Mctp2, and a lncRNA. The congenic segments of these two BP QTLs overlapped between 134.09 Mb and 134.52 Mb. No exonic variants were detected in any of the genes. These findings reiterate complexity of genetic regulation of BP within QTL regions, where elements beyond protein-coding sequences could be factors in controlling BP.

8.
Cell Rep ; 25(3): 677-689.e4, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30332647

RESUMO

Dietary salt reduction and exercise are lifestyle modifications for salt-sensitive hypertensives. While exercise has prominent metabolic effects, salt has an adverse effect on metabolic syndrome, of which hypertension is a hallmark. We hypothesized that dietary salt impacts metabolism in a salt-sensitive model of hypertension. An untargeted metabolomic approach demonstrates lower circulating levels of the ketone body, beta-hydroxybutyrate (ßOHB), in high salt-fed hypertensive rats. Despite the high salt intake, specific rescue of ßOHB levels by nutritional supplementation of its precursor, 1,3-butanediol, attenuates hypertension and protects kidney function. This beneficial effect of ßOHB was likely independent of gut-microbiotal and Th17-mediated effects of salt and instead facilitated by ßOHB inhibiting the renal Nlrp3 inflammasome. The juxtaposed effects of dietary salt and exercise on salt-sensitive hypertension, which decrease and increase ßOHB respectively, indicate that nutritional supplementation of a precursor of ßOHB provides a similar benefit to salt-sensitive hypertension as exercise.


Assuntos
Ácido 3-Hidroxibutírico/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Hipertensão/prevenção & controle , Inflamassomos/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Cloreto de Sódio na Dieta/toxicidade , Ácido 3-Hidroxibutírico/administração & dosagem , Animais , Pressão Sanguínea , Aromatizantes/toxicidade , Hipertensão/induzido quimicamente , Hipertensão/metabolismo , Inflamassomos/imunologia , Inflamassomos/metabolismo , Masculino , Ratos , Ratos Endogâmicos Dahl
9.
Hypertension ; 72(5): 1125-1132, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30354811

RESUMO

G-protein-coupled estrogen receptor, Gper1, has been implicated in cardiovascular disease, but its mechanistic role in blood pressure control is poorly understood. Here, we demonstrate that genetically salt-sensitive hypertensive rats with complete genomic excision of Gper1 by a multiplexed guide RNA CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9 (CRISPR associated proteins) approach present with lower blood pressure, which was accompanied by altered microbiota, different levels of circulating short chain fatty acids, and improved vascular relaxation. Microbiotal transplantation from hypertensive Gper1+/+ rats reversed the cardiovascular protective effect exerted by the genomic deletion of Gper1. Thus, this study reveals a role for Gper1 in promoting microbiotal alterations that contribute to cardiovascular pathology. However, the exact mechanism by which Gper1 regulates blood pressure is still unknown. Our results indicate that the function of Gper1 is contextually dependent on the microbiome, whereby, contemplation of using Gper1 as a target for therapy of cardiovascular disease requires caution.


Assuntos
Disbiose/fisiopatologia , Microbioma Gastrointestinal/fisiologia , Hipertensão/fisiopatologia , Receptores Acoplados a Proteínas-G/genética , Animais , Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , RNA Guia , Ratos , Ratos Endogâmicos Dahl
10.
J Hypertens ; 36(7): 1486-1491, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29634662

RESUMO

BACKGROUND: Previously, using linkage analysis and substitution mapping, two closely-linked interactive blood pressure quantitative trait loci (QTLs), BP QTL1 and BP QTL2, were located within a 13.96 Mb region from 117894038 to 131853815 bp (RGSC 3.4 version) on rat chromosome 5 (RNO5). This was done by using a series of congenic strains consisting of genomic segments of the Dahl salt-sensitive (S) rat substituted with that of the normotensive Lewis (LEW) rat. The interactive nature of the two loci was further confirmed by the construction and characterization of a panel of S.LEW bicongenic strains and corresponding S.LEW monocongenic strains, which provided definitive evidence of epistasis (genetic interaction) between BP QTL1 (7.77 Mb) and BP QTL2 (4.18 Mb). The purpose of this work was to further map these interacting QTLs. METHOD: A new panel of seven new S.LEW bicongenic strains was constructed and characterized for BP. RESULTS: The data obtained from these new strains further resolved BP QTL1 from 7.77 to 2.93 Mb. Further, BP QTL2 was traceable as not being a single QTL, but a composite of at least three QTLs, LEW alleles at two of which located within 2.26 Mb and 175 kb lowered BP but the third one located within 1.31 Mb increased BP. CONCLUSION: Lack of coding variation within any of the regions further mapped within the previous QTL2 suggests noncoding variation as likely responsible for the observed epistasis.


Assuntos
Pressão Sanguínea/genética , Epistasia Genética , Hipertensão/genética , Locos de Características Quantitativas , Alelos , Animais , Animais Congênicos , Mapeamento Cromossômico , Ratos , Ratos Endogâmicos Dahl , Ratos Endogâmicos Lew
11.
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
12.
Gut Microbes ; 9(5): 400-421, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29469650

RESUMO

BACKGROUND: Conditions of excess androgen in women, such as polycystic ovary syndrome (PCOS), often exhibit intergenerational transmission. One way in which the risk for PCOS may be increased in daughters of affected women is through exposure to elevated androgens in utero. Hyperandrogenemic conditions have serious health consequences, including increased risk for hypertension and cardiovascular disease. Recently, gut dysbiosis has been found to induce hypertension in rats, such that blood pressure can be normalized through fecal microbial transplant. Therefore, we hypothesized that the hypertension seen in PCOS has early origins in gut dysbiosis caused by in utero exposure to excess androgen. We investigated this hypothesis with a model of prenatal androgen (PNA) exposure and maternal hyperandrogenemia by single-injection of testosterone cypionate or sesame oil vehicle (VEH) to pregnant dams in late gestation. We then completed a gut microbiota and cardiometabolic profile of the adult female offspring. RESULTS: The metabolic assessment revealed that adult PNA rats had increased body weight and increased mRNA expression of adipokines: adipocyte binding protein 2, adiponectin, and leptin in inguinal white adipose tissue. Radiotelemetry analysis revealed hypertension with decreased heart rate in PNA animals. The fecal microbiota profile of PNA animals contained higher relative abundance of bacteria associated with steroid hormone synthesis, Nocardiaceae and Clostridiaceae, and lower abundance of Akkermansia, Bacteroides, Lactobacillus, Clostridium. The PNA animals also had an increased relative abundance of bacteria associated with biosynthesis and elongation of unsaturated short chain fatty acids (SCFAs). CONCLUSIONS: We found that prenatal exposure to excess androgen negatively impacted cardiovascular function by increasing systolic and diastolic blood pressure and decreasing heart rate. Prenatal androgen was also associated with gut microbial dysbiosis and altered abundance of bacteria involved in metabolite production of short chain fatty acids. These results suggest that early-life exposure to hyperandrogenemia in daughters of women with PCOS may lead to long-term alterations in gut microbiota and cardiometabolic function.


Assuntos
Androgênios/efeitos adversos , Disbiose/microbiologia , Hipertensão/etiologia , Exposição Materna/efeitos adversos , Síndrome do Ovário Policístico/complicações , Efeitos Tardios da Exposição Pré-Natal/microbiologia , Testosterona/análogos & derivados , Adipocinas/metabolismo , Tecido Adiposo Branco/metabolismo , Adulto , Androgênios/administração & dosagem , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Pressão Sanguínea , Disbiose/etiologia , Disbiose/metabolismo , Disbiose/fisiopatologia , Ácidos Graxos Voláteis/metabolismo , Feminino , Microbioma Gastrointestinal , Frequência Cardíaca , Humanos , Hipertensão/metabolismo , Hipertensão/microbiologia , Hipertensão/fisiopatologia , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Ratos , Ratos Wistar , Testosterona/administração & dosagem , Testosterona/efeitos adversos
13.
PLoS Genet ; 13(8): e1006961, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28827789

RESUMO

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.


Assuntos
Pressão Sanguínea/genética , Hipertensão/genética , Proteínas do Tecido Nervoso/genética , RNA Longo não Codificante/genética , Alelos , Animais , Sistemas CRISPR-Cas/genética , Clonagem Molecular , Eletrocardiografia , Técnicas de Introdução de Genes , Coração/fisiopatologia , Humanos , Hipertensão/fisiopatologia , Mutação INDEL/genética , Nucleotídeos/genética , Locos de Características Quantitativas/genética , RNA Longo não Codificante/isolamento & purificação , Ratos
14.
Physiology (Bethesda) ; 32(3): 224-233, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28404738

RESUMO

Hypertension, or elevated blood pressure (BP), has been extensively researched over decades and clearly demonstrated to be caused due to a combination of host genetic and environmental factors. Although much research remains to be conducted to pin-point the precise genetic elements on the host genome that control BP, new lines of evidence are emerging to indicate that, besides the host genome, the genomes of all indigenous commensal micro-organisms, collectively referred to as the microbial metagenome or microbiome, are important, but largely understudied, determinants of BP. Unlike the rigid host genome, the microbiome or the "second genome" can be altered by diet or microbiotal transplantation in the host. This possibility is attractive from the perspective of exploiting the microbiotal composition for clinical management of inherited hypertension. Thus, focusing on the limited current literature supporting a role for the microbiome in BP regulation, this review highlights the need to further explore the role of the co-existence of host and the microbiota as an organized biological unit called the "holobiont" in the context of BP regulation.


Assuntos
Hipertensão/genética , Hipertensão/microbiologia , Metagenoma , Microbiota , Animais , Humanos , Camundongos
15.
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
16.
Bone ; 92: 85-93, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27554428

RESUMO

Rankl, the major pro-osteoclastogenic cytokine, is synthesized as a transmembrane protein that can be cleaved by specific endopeptidases to release a soluble form (sRankl). We have previously reported that interleukin-33 (IL-33) induces expression of Tnfsf11, the Rankl-encoding gene, in primary osteoblasts, but we failed to detect sRankl in the medium. Since we also found that PTH treatment caused sRankl release in a similar experimental setting, we directly compared the influence of the two molecules. Here we show that treatment of primary murine osteoblasts with PTH causes sRankl release into the medium, whereas IL-33 only induces Tnfsf11 expression. This difference was not explainable by alternative splicing or by PTH-specific induction of endopeptidases previously shown to facilitate Rankl processing. Since sRankl release after PTH administration was blocked in the presence a broad-spectrum matrix metalloprotease inhibitor, we applied genome-wide expression analyses to identify transcriptional targets of PTH in osteoblasts. We thereby confirmed some of the effects of PTH established in other systems, but additionally identified few PTH-induced genes encoding metalloproteases. By comparing expression of these genes following administration of IL-33, PTH and various other Tnfsf11-inducing molecules, we observed that PTH was the only molecule simultaneously inducing sRankl release and Adamts1 expression. The functional relevance of the putative influence of PTH on Rankl processing was further confirmed in vivo, as we found that daily injection of PTH into wildtype mice did not only increase bone formation, but also osteoclastogenesis and sRankl concentrations in the serum. Taken together, our findings demonstrate that transcriptional effects on Tnfsf11 expression do not generally trigger sRankl release and that PTH has a unique activity to promote the proteolytic processing of Rankl.


Assuntos
Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Hormônio Paratireóideo/farmacologia , Proteólise/efeitos dos fármacos , Ligante RANK/biossíntese , Ligante RANK/genética , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
17.
PLoS One ; 11(4): e0153519, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27073989

RESUMO

This study is focused on a translationally significant, genome-wide-association-study (GWAS) locus for cardiovascular disease (QT-interval) on human chromosome 17. We have previously validated and high resolution mapped the homologous genomic segment of this human locus to <42.5 kb on rat chromosome 10. This <42.5 kb segment in rats regulates both QT-interval and blood pressure and contains a single protein-coding gene, rififylin (Rffl). The expression of Rffl in the hearts and kidneys is differential between Dahl S and S.LEW congenic rats, which are the strains used for mapping this locus. Our previous study points to altered rate of endocytic recycling as the underlying mechanism, through which Rffl operates to control both QT-interval and blood pressure. Interestingly, Rffl also contributes to tumorigenesis by repressing caspases and tumor suppressor genes. Moreover, the expression of Methyl-CpG Binding Domain Protein 2 (Mbd2) in the hearts and kidneys is also higher in the S.LEW congenic strain than the background (control) Dahl S strain. Mbd2 can repress methylated tumor suppressor genes. These data suggest that the S.LEW congenic strain could be more susceptible to tumorigenesis. To test this hypothesis, the S and S.LEW strains were compared for susceptibility to azoxymethane-induced colon tumors. The number of colon tumors was significantly higher in the S.LEW congenic strain compared with the S rat. Transcriptomic analysis confirmed that the chemical carcinogenesis pathway was significantly up-regulated in the congenic strain. These studies provide evidence for a GWAS-validated genomic segment on rat chromosome 10 as being important for the regulation of cardiovascular function and tumorigenesis.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Pressão Sanguínea/genética , Carcinogênese/genética , Hipertensão/genética , Locos de Características Quantitativas , Ubiquitina-Proteína Ligases/genética , Animais , Animais Congênicos , Apoptose/genética , Determinação da Pressão Arterial , Humanos , Característica Quantitativa Herdável , Ratos , Ratos Endogâmicos Dahl , Ratos Endogâmicos Lew , Especificidade da Espécie
18.
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
19.
Physiol Genomics ; 47(6): 187-97, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25829393

RESUMO

The gut microbiota plays a critical role in maintaining physiological homeostasis. This study was designed to evaluate whether gut microbial composition affects hypertension. 16S rRNA genes obtained from cecal samples of Dahl salt-sensitive (S) and Dahl salt-resistant (R) rats were sequenced. Bacteria of the phylum Bacteroidetes were higher in the S rats compared with the R rats. Furthermore, the family S24-7 of the phylum Bacteroidetes and the family Veillonellaceae of the phylum Firmicutes were higher in the S rats compared with the R rats. Analyses of the various phylogenetic groups of cecal microbiota revealed significant differences between S and R rats. Both strains were maintained on a high-salt diet, administered antibiotics for ablation of microbiota, transplanted with S or R rat cecal contents, and monitored for blood pressure (BP). Systolic BP of the R rats remained unaltered irrespective of S or R rat cecal transplantation. Surprisingly, compared with the S rats given S rat cecal content, systolic BP of the S rats given a single bolus of cecal content from R rats was consistently and significantly elevated during the rest of their life, and they had a shorter lifespan. A lower level of fecal bacteria of the family Veillonellaceae and increased plasma acetate and heptanoate were features associated with the increased BP observed in the S rats given R rat microbiota compared with the S rats given S rat microbiota. These data demonstrate a link between microbial content and BP regulation and, because the S and R rats differ in their genomic composition, provide the necessary basis to further examine the relationship between the host genome and microbiome in the context of BP regulation in the Dahl rats.


Assuntos
Microbioma Gastrointestinal , Hipertensão/microbiologia , Animais , Antibacterianos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Ceco/efeitos dos fármacos , Ceco/microbiologia , Ceco/transplante , Ácidos Graxos/sangue , Microbioma Gastrointestinal/efeitos dos fármacos , Variação Genética , Genoma , Hipertensão/sangue , Hipertensão/fisiopatologia , Estimativa de Kaplan-Meier , Longevidade , Metabolômica , Ratos Endogâmicos Dahl , Sódio/sangue , Sódio/urina , Sístole/efeitos dos fármacos
20.
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
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