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1.
Pharmacol Rep ; 72(1): 179-187, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32016843

RESUMO

BACKGROUND: Benign prostatic hyperplasia (BPH) is associated with obesity and prostatic inflammation. The present study investigated the participation of toll-like receptor 9 (TLR9) in obesity-induced BPH, focusing on metabolic impairments, damage-associated molecular patterns (DAMP) levels and prostatic oxidative stress generation. METHODS: C57BL/6 (WT) and TLR9 mutant male mice were fed with regular or high-fat diet for 12 weeks. Metabolic profile, functional protocols, reactive-oxygen species (ROS) generation, prostatic histological analysis and DAMP levels were analyzed. Western blotting for prostatic TLR9 signaling pathway was also performed. RESULTS: BPH in WT obese animals was characterized by increased prostate weight, smooth muscle hypercontractility and prostatic epithelial hyperplasia. Higher epididymal fat weight and prostatic ROS generation along with increased fasting glucose, triglyceride and circulating DAMP levels were also observed in WT obese group. Conversely, TLR9 mutant obese animals exhibited lower epididymal fat weight, fasting glucose and triglyceride levels associated with reduced prostate hypercontractility, prostatic ROS and circulating DAMP levels. However, TLR9 mutant obese mice were not protected from obesity-associated prostatic overgrowth and epithelial hyperplasia. Interestingly, TLR9 mutant lean mice exhibited augmented fasting glucose and prostatic ROS levels compared with WT lean mice. Despite increased prostatic expression of TLR9 in WT obese mice, no differences were seen in MyD88 expression between groups. CONCLUSION: Improved obesity-induced BPH-related prostatic smooth muscle hypercontractility in TLR9 obese mice may be associated with amelioration in the metabolic profile, ROS and DAMP generation. Therefore, TLR9 could be a valuable target to improve obesity-associated metabolic disorders and prostate smooth muscle hypercontractility in BPH.

2.
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.

3.
Vascul Pharmacol ; 125-126: 106633, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31843471

RESUMO

Commensal microbiota within a holobiont contribute to the overall health of the host via mutualistic symbiosis. Disturbances in such symbiosis is prominently correlated with a variety of diseases affecting the modern society of humans including cardiovascular diseases, which are the number one contributors to human mortality. Given that a hallmark of all cardiovascular diseases is changes in vascular function, we hypothesized that depleting microbiota from a holobiont would induce vascular dysfunction. To test this hypothesis, young mice of both sexes raised in germ-free conditions were examined vascular contractility and structure. Here we observed that male and female germ-free mice presented a decrease in contraction of resistance arteries. These changes were more pronounced in germ-free males than in germ-free females mice. Furthermore, there was a distinct change in vascular remodeling between males and females germ-free mice. Resistance arteries from male germ-free mice demonstrated increased vascular stiffness, as shown by the leftward shift in the stress-strain curve and inward hypotrophic remodeling, a characteristic of chronic reduction in blood flow. On the other hand, resistance arteries from germ-free female mice were similar in the stress-strain curves to that of conventionally raised mice, but were distinctly different and showed outward hypertrophic remodeling, a characteristic seen in aging. Interestingly, we observed that reactive oxygen species (ROS) generation from bone marrow derived neutrophils is blunted in female germ-free mice, but it is exacerbated in male germ-free mice. In conclusion, these observations indicate that commensal microbiota of a holobiont are central to maintain proper vascular function and structure homeostasis, especially in males.

4.
Am J Physiol Heart Circ Physiol ; 317(5): H1013-H1027, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31469290

RESUMO

Insufficient autophagy has been proposed as a mechanism of cellular aging, as this leads to the accumulation of dysfunctional macromolecules and organelles. Premature vascular aging occurs in hypertension. In fact, many factors that contribute to the deterioration of vascular function as we age are accelerated in clinical and experimental hypertension. Previously, we have reported decreased autophagy in arteries from spontaneously hypertensive rats (SHRs); however, the effects of restoring autophagic activity on blood pressure and vascular function are currently unknown. We hypothesized that reconstitution of arterial autophagy in SHRs would decrease blood pressure and improve endothelium-dependent relaxation. We treated 14- to 18-wk-old Wistar rats (n = 7 vehicle and n = 8 trehalose) and SHRs (n = 7/group) with autophagy activator trehalose (2% in drinking water) for 28 days. Blood pressure was measured by radiotelemetry, and vascular function and structure were measured in isolated mesenteric resistance arteries (MRAs) using wire and pressure myographs, respectively. Treatment with trehalose had no effect on blood pressure in SHRs; however, isolated MRAs presented enhanced relaxation to acetylcholine, in a cyclooxygenase- and reactive oxygen species-dependent manner. Similarly, trehalose treatment shifted the relaxation to the Rho kinase (ROCK) inhibitor Y-27632 to the right, indicating reduced ROCK activity. Finally, trehalose treatment decreased arterial stiffness as indicated by the slope of the stress-strain curve. Overall these data indicate that reconstitution of arterial autophagy in SHRs improves endothelial and vascular smooth muscle function, which could synergize to prevent stiffening. As a result, restoration of autophagic activity could be a novel therapeutic for premature vascular aging in hypertension.NEW & NOTEWORTHY This work supports the concept that diminished arterial autophagy contributes to premature vascular aging in hypertension and that therapeutic reconstitution of autophagic activity can ameliorate this phenotype. As vascular age is a new clinically used index for cardiovascular risk, understanding this mechanism may assist in the development of new drugs to prevent premature vascular aging in hypertension.

5.
Am J Hypertens ; 32(8): 709-719, 2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-30982879

RESUMO

Hypertension has been described as a condition of premature vascular aging, relative to actual chronological age. In fact, many factors that contribute to the deterioration of vascular function as we age are accelerated in hypertension. Nonetheless, the precise mechanisms that underlie the aged phenotype of arteries from hypertensive patients and animals remain elusive. Cellular senescence is an age-related physiologic process in which cells undergo irreversible growth arrest. Although controlled senescence negatively regulates cell proliferation and promotes tissue regeneration, uncontrolled senescence can contribute to disease pathogenesis by presenting the senescence-associated secretory phenotype, in which molecules such as proinflammatory cytokines, matrix metalloproteases, and reactive oxygen species are released into tissue microenvironments. This review will address and critically evaluate the current literature on the role of cellular senescence in hypertension, with particular emphasis on cells types that mediate and modulate vascular function and structure.

6.
Pharmacol Res ; 141: 276-290, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30639374

RESUMO

Several human diseases, include cancer and stroke are characterized by changes in immune system activation and vascular contractility. However, the mechanistic foundation of a vascular immuno-physiology network is still largely unknown. Formyl peptide receptor-1 (FPR-1), which plays a vital role in the function of the innate immune system, is widely expressed in arteries, but its role in vascular plasticity is unclear. We questioned why a receptor that is crucial for immune defense, and cell motility in leukocytes, would be expressed in vascular smooth muscle cells (VSMCs). We hypothesized that activation of FPR-1 in arteries is important for the temporal reorganization of actin filaments, and consequently, changes in vascular function, similar to what is observed in neutrophils. To address our hypothesis, we used FPR-1 knockout and VSMCs lacking FPR-1. We observed that FPR-1 activation induces actin polymerization in wild type VSMCs. Absence of FPR-1 in the vasculature significantly decreased vascular contraction and induced loss of myogenic tone to elevated intraluminal pressures via disruption of actin polymerization. Actin polymerization activator ameliorated these responses. In conclusion, we have established a novel role for FPR-1 in VSMC contractility and motility, similar to the one observed in sentinel cells of the innate immune system. This discovery is fundamental for vascular immuno-pathophysiology, given that FPR-1 in VSMCs not only functions as an immune system receptor, but it also has an important role for the dynamic plasticity of arteries.


Assuntos
Actinas/metabolismo , Artérias/fisiologia , Contração Muscular , Músculo Liso Vascular/fisiologia , Receptores de Formil Peptídeo/metabolismo , Animais , Artérias/citologia , Células Cultivadas , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/citologia , Receptores de Formil Peptídeo/genética
7.
Clin Sci (Lond) ; 132(13): 1433-1438, 2018 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-30021912

RESUMO

Sepsis is a profoundly morbid and life-threatening condition, and an increasingly alarming burden on modern healthcare economies. Patients with septic shock exhibit persistent hypotension despite adequate volume resuscitation requiring pharmacological vasoconstrictors, but the molecular mechanisms of this phenomenon remain unclear. The accumulation of misfolded proteins is linked to numerous diseases, and it has been observed that soluble oligomeric protein intermediates are the primary cytotoxic species in these conditions. Oligomeric protein assemblies have been shown to bind and activate a variety of pattern recognition receptors (PRRs) including formyl peptide receptor (FPR). While inhibition of endoplasmic reticulum (ER) stress and stabilization of protein homeostasis have been promising lines of inquiry regarding sepsis therapy, little attention has been given to the potential effects that the accumulation of misfolded proteins may have in driving sepsis pathogenesis. Here we propose that in sepsis, there is an accumulation of toxic misfolded proteins in the form of soluble protein oligomers (SPOs) that contribute to the inflammation and vascular dysfunction observed in sepsis via the activation of one or more PRRs including FPR. Our laboratory has shown increased levels of SPOs in the heart and intrarenal arteries of septic mice. We have also observed that exposure of resistance arteries and vascular smooth muscle cells to SPOs is associated with increased mitogen-activated protein kinase (MAPK) signaling including phosphorylated extracellular signal-regulated kinase (p-ERK) and p-P38 MAPK pathways, and that this response is abolished with the knockout of FPR. This hypothesis has promising clinical implications as it proposes a novel mechanism that can be exploited as a therapeutic target in sepsis.


Assuntos
Imunidade Inata , Inflamação/imunologia , Sepse/imunologia , Doenças Vasculares/imunologia , Humanos , Deficiências na Proteostase/imunologia , Receptores de Reconhecimento de Padrão/imunologia
9.
Am J Hypertens ; 31(10): 1067-1078, 2018 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-29788246

RESUMO

Morphological and physiological changes in the vasculature have been described in the evolution and maintenance of hypertension. Hypertension-induced vascular dysfunction may present itself as a contributing, or consequential factor, to vascular remodeling caused by chronically elevated systemic arterial blood pressure. Changes in all vessel layers, from the endothelium to the perivascular adipose tissue (PVAT), have been described. This mini-review focuses on the current knowledge of the structure and function of the vessel layers, specifically muscular arteries: intima, media, adventitia, PVAT, and the cell types harbored within each vessel layer. The contributions of each cell type to vessel homeostasis and pathophysiological development of hypertension will be highlighted.


Assuntos
Pressão Arterial , Artérias/patologia , Artérias/fisiopatologia , Hipertensão/patologia , Hipertensão/fisiopatologia , Remodelação Vascular , Tecido Adiposo/patologia , Tecido Adiposo/fisiopatologia , Animais , Humanos , Túnica Íntima/patologia , Túnica Íntima/fisiopatologia , Túnica Média/patologia , Túnica Média/fisiopatologia
11.
J Pharmacol Exp Ther ; 365(1): 60-71, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29348267

RESUMO

Traditionally, Toll-like receptor 9 (TLR9) signals through an MyD88-dependent cascade that results in proinflammatory gene transcription. Recently, it was reported that TLR9 also participates in a stress tolerance signaling cascade in nonimmune cells. In this noncanonical pathway, TLR9 binds to and inhibits sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 2 (SERCA2), modulating intracellular calcium handling, and subsequently resulting in the activation of 5'-AMP-activated protein kinase α (AMPKα). We have previously reported that TLR9 causes increased contraction in isolated arteries; however, the mechanisms underlying this vascular dysfunction need to be further clarified. Therefore, we hypothesized that noncanonical TLR9 signaling was also present in vascular smooth muscle cells (VSMCs) and that it mediates enhanced contractile responses through SERCA2 inhibition. To test these hypotheses, aortic microsomes, aortic VSMCs, and isolated arteries from male Sprague-Dawley rats were incubated with vehicle or TLR9 agonist (ODN2395). Despite clear AMPKα activation after treatment with ODN2395, SERCA2 activity was unaffected. Alternatively, ODN2395 caused the phosphorylation of AMPKα via transforming growth factor ß-activated kinase 1 (TAK1), a kinase involved in TLR9 inflammatory signaling. Downstream, we hypothesized that that TLR9 activation of AMPKα may be important in mediating actin cytoskeleton reorganization. ODN2395 significantly increased the filamentous-to-globular actin ratio, as well as indices of RhoA/Rho-associated protein kinase (ROCK) activation, with the latter being prevented by AMPKα inhibition. In conclusion, AMPKα phosphorylation after TLR9 activation in VSMCs appears to be an extension of traditional inflammatory signaling via TAK1, as opposed to SERCA2 inhibition and the noncanonical pathway. Nonetheless, TLR9-AMPKα signaling can mediate VSMC function via RhoA/ROCK activation and actin polymerization.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Actinas/química , MAP Quinase Quinase Quinases/metabolismo , Músculo Liso Vascular/citologia , Multimerização Proteica , Receptor Toll-Like 9/metabolismo , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Ativação Enzimática , Regulação Enzimológica da Expressão Gênica , Masculino , Fosforilação , Estrutura Quaternária de Proteína , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
12.
J Trauma Acute Care Surg ; 83(6): 1062-1065, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28806285

RESUMO

BACKGROUND: Mitochondrial damage-associated molecular patterns (mtDAMPs), such as mitochondrial DNA and N-formylated peptides, are endogenous molecules released from tissue after traumatic injury. mtDAMPs are potent activators of the innate immune system. They have similarities with bacteria, which allow mtDAMPs to interact with the same pattern recognition receptors and mediate the development of systemic inflammatory response syndrome (SIRS). Current recommendations for management of an open abdomen include returning to the operating room every 48 hours for peritoneal cavity lavage until definitive procedure. These patients are often critically ill and develop SIRS. We hypothesized that mitochondrial DAMPs are present in the peritoneal cavity fluid in this setting, and that they accumulate in the interval between washouts. METHODS: We conducted a prospective pilot study of critically ill adult patients undergoing open abdomen management in the surgical and trauma intensive care units. Peritoneal fluid was collected daily from 10 open abdomen patients. Specimens were analyzed via quantitative polymerase chain reaction (qPCR) for mitochondrial DNA (mtDNA), via enzyme immunoassay for DNAse activity and via Western blot analysis for the ND6 subunit of the NADH: ubiquinone oxidoreductase, an N-formylated peptide. RESULTS: We observed a reduction in the expression of ND6 the day after lavage of the peritoneal cavity, that was statistically different from the days with no lavage (% change in ND6 expression, postoperative from washout: -50 ± 11 vs. no washout day, 42 ± 9; p < 0.05). Contrary to expectation, the mtDNA levels remained relatively constant from sample to sample. We then hypothesized that DNAse present in the effluent may be degrading mtDNA. CONCLUSION: These results indicate that the peritoneal cavity irrigation reduces the presence of mitochondrial DAMPs in the open abdomen. It is possible that increased frequency of peritoneal cavity lavage may lead to decreased systemic absorption of mtDAMPs, thereby reducing the risk of SIRS. LEVEL OF EVIDENCE: Prospective study, Case Series, Level V.


Assuntos
Traumatismos Abdominais/genética , DNA Mitocondrial/genética , Mitocôndrias/metabolismo , Lavagem Peritoneal/métodos , Traumatismos Abdominais/metabolismo , Traumatismos Abdominais/terapia , Adulto , DNA Mitocondrial/metabolismo , Feminino , Humanos , Masculino , Projetos Piloto , Estudos Prospectivos
13.
Am J Hypertens ; 30(2): 173-181, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27623761

RESUMO

BACKGROUND: Innate immune system responses to damage-associated molecular patterns (DAMPs) are involved in hypertension. However, the mechanisms of this contribution are not well understood. Circulating mitochondrial DNA is a DAMP that activates Toll-like receptor (TLR) 9 and is elevated in spontaneously hypertensive rats (SHR). Therefore, we hypothesized that lysosomotropic agent chloroquine (CQ) would impair TLR9 signaling, as well as prevent the development of hypertension and immune cell recruitment to the vasculature, in SHR. METHODS: Initially, adult SHR and Wistar-Kyoto (WKY) rats (12 weeks old), as well as a group of young SHR (5 weeks old), were treated with CQ (40mg/kg/day) or vehicle (saline) via intraperitoneal injections for 21 days and then TLR9-myeloid differentiation primary response protein (MyD88) signaling proteins were assessed in mesenteric resistance arteries (MRA) via western blot. Subsequently, young SHR and WKY were treated from 5-8 weeks of age and then were allowed to mature without further treatment. Blood pressure was measured pretreatment, posttreatment, and after maturation, and immune cell recruitment to the vasculature was measured via flow cytometry after maturation. RESULTS: In MRA from adult SHR, CQ increased the expression of MyD88-dependent proteins, whereas young SHR MRA exhibited a decrease. This inhibition was subsequently associated with suppression of blood pressure, as well as decreased counts of circulating T cells and vascular infiltrating leukocytes in SHR, when CQ was administered during the prehypertensive phase. CONCLUSIONS: These data bring into question the participation of TLRs during the maintenance phase of hypertension and promote the exploration of innate immune system therapy during the critical developmental phase.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Cloroquina/administração & dosagem , Hipertensão/tratamento farmacológico , Animais , Western Blotting , Modelos Animais de Doenças , Progressão da Doença , Relação Dose-Resposta a Droga , Citometria de Fluxo , Hipertensão/imunologia , Hipertensão/fisiopatologia , Imunidade Inata , Masculino , Artérias Mesentéricas/metabolismo , Artérias Mesentéricas/patologia , Artérias Mesentéricas/fisiopatologia , Fator 88 de Diferenciação Mieloide/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Receptor Toll-Like 9/metabolismo , Resistência Vascular/efeitos dos fármacos
14.
Diabetes ; 65(12): 3754-3764, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27650857

RESUMO

Diabetic bladder dysfunction (DBD) is a common urological complication of diabetes. Innate immune system activation via Toll-like receptor 4 (TLR4) leads to inflammation and oxidative stress and was implicated in diabetes pathophysiology. We hypothesized that bladder hypertrophy and hypercontractility in DBD is mediated by TLR4 activation. Wild-type (WT) and TLR4 knockout (TLR4KO) mice were made diabetic by streptozotocin (STZ) treatment, and bladder contractile function and TLR4 pathway expression were evaluated. Immunohistochemistry confirmed the expression of TLR4 in human and mouse bladder. Recombinant high-mobility group box protein 1 (HMGB1) increased bladder TLR4 and MyD88 expression and enhanced contractile response to electrical field stimulation. Bladder expression of TLR4 and MyD88 and serum expression of HMGB1 were increased in STZ compared with control mice. Carbachol (CCh)-mediated contraction was increased in bladders from STZ mice, and TLR4 inhibitor CLI-095 attenuated this increase. Induction of diabetes by STZ in WT mice increased bladder weight and contractile responses to CCh and to electrical field stimulation. TLR4KO mice were not protected from STZ-induced diabetes; however, despite levels of hyperglycemia similar to those of WT STZ mice, TLR4KO STZ mice were protected from diabetes-induced bladder hypertrophy and hypercontractility. These data suggest that TLR4 activation during diabetes mediates DBD-associated bladder hypertrophy and hypercontractility.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/metabolismo , Receptor 4 Toll-Like/metabolismo , Bexiga Urinária/metabolismo , Animais , Carbacol/farmacologia , Diabetes Mellitus Tipo 1/metabolismo , Modelos Animais de Doenças , Proteína HMGB1/metabolismo , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Receptor 4 Toll-Like/genética , Bexiga Urinária/efeitos dos fármacos
15.
Pharmacol Res ; 113(Pt A): 384-394, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27639600

RESUMO

It has been suggested that hypertension results from a loss of immunological tolerance and the resulting autoimmunity may be an important underlying factor of its pathogenesis. This stems from the observations that many of the features involved in autoimmunity are also implicated in hypertension. Furthermore, the underlying presence of hypertension and cardiovascular disease are frequently observed in patients with autoimmune diseases. Antimalarial agents such as chloroquine are generally among the first line treatment options for patients with autoimmune diseases; however, whether they can improve a hypertensive phenotype in a genetic model of essential hypertension remains to be clarified. Therefore, we hypothesized that chloroquine treatment would improve endothelial function and lower blood pressure in spontaneously hypertensive rats (SHR). We treated adult SHR and Wistar-Kyoto rats (12 weeks old), as well as a group of young SHR (5 weeks old), with chloroquine (40mg/kg/day via intraperitoneal injection) for 21 days. Chloroquine lowered blood pressure in adult SHR, but did not impede the development of high blood pressure in young SHR. In isolated mesenteric resistance arteries from SHR of both ages, chloroquine treatment inhibited cyclooxygenase-dependent contraction to acetylcholine, lowered vascular and systemic generation of reactive oxygen species, and improved nitric oxide bioavailability. Overall, these data reveal the anti-hypertensive mechanisms of chloroquine in the vasculature, which may be important for lowering risk of cardiovascular disease in patients with autoimmune diseases. Furthermore, it adds to the growing body of evidence suggesting that autoimmunity underlies hypertension.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Cloroquina/farmacologia , Endotélio Vascular/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Acetilcolina/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Doenças Autoimunes/tratamento farmacológico , Endotélio Vascular/metabolismo , Hipertensão/metabolismo , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/metabolismo , Óxido Nítrico/metabolismo , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Espécies Reativas de Oxigênio/metabolismo
16.
Front Immunol ; 7: 297, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27532003

RESUMO

The major pathophysiological characteristic of systemic inflammatory response syndrome (SIRS) and sepsis is the loss of control of vascular tone and endothelial barrier dysfunction. These changes are attributed to pro-inflammatory mediators. It has been proposed that in patients and rats without infection, cell components from damaged tissue are the primary instigators of vascular damage. Mitochondria share several characteristics with bacteria, and when fragments of mitochondria are released into the circulation after injury, they are recognized by the innate immune system. N-Formyl peptides are common molecular signatures of bacteria and mitochondria and are known to play a role in the initiation of inflammation by activating the formyl peptide receptor (FPR). We have demonstrated that infusion of mitochondrial N-formyl peptides (F-MIT) leads to sepsis-like symptoms, including vascular leakage. We have also observed that F-MIT, via FPR activation, elicits changes in cytoskeleton-regulating proteins in endothelial cells. Therefore, we hypothesize that these FPR-mediated changes in cytoskeleton can cause endothelial cell contraction and, consequently vascular leakage. Here, we propose that endothelial FPR is a key contributor to impaired barrier function in SIRS and sepsis patients following trauma.

17.
Am J Physiol Heart Circ Physiol ; 310(8): H1015-25, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26873968

RESUMO

Bacterial infections increase risk for pregnancy complications, such as preeclampsia and preterm birth. Unmethylated CpG DNA sequences are present in bacterial DNA and have immunostimulatory effects. Maternal exposure to CpG DNA induces fetal demise and craniofacial malformations; however, the effects of CpG DNA on maternal cardiovascular health have not been examined. We tested the hypothesis that exposure to synthetic CpG oligonucleotides (ODNs) during gestation would increase blood pressure and cause vascular dysfunction in pregnant rats. Pregnant and nonpregnant female rats were treated with CpG ODN (ODN 2395) or saline (Veh) starting on gestational day 14or corresponding day for the nonpregnant groups. Exposure to CpG ODN increased systolic blood pressure in pregnant (Veh: 121 ± 2 mmHg vs. ODN 2395: 134 ± 2 mmHg,P< 0.05) but not in nonpregnant rats (Veh: 111 ± 2 mmHg vs. ODN 2395: 108 ± 5 mmHg,P> 0.05). Mesenteric resistance arteries from pregnant CpG ODN-treated rats had increased contractile responses to U46619 [thromboxane A2(TxA2) mimetic] compared with arteries from vehicle-treated rats [Emax(%KCl), Veh: 87 ± 4 vs. ODN 2395: 104 ± 4,P< 0.05]. Nitric oxide synthase (NOS) inhibition increased contractile responses to U46619, and CpG ODN treatment abolished this effect in arteries from pregnant ODN 2395-treated rats. CpG ODN potentiated the involvement of cyclooxygenase (COX) to U46619-induced contractions. In conclusion, exposure to CpG ODN during gestation induces maternal hypertension, augments resistance artery contraction, increases the involvement of COX-dependent mechanisms and reduces the contribution of NOS-dependent mechanisms to TxA2-induced contractions in mesenteric resistance arteries.


Assuntos
Pressão Arterial/efeitos dos fármacos , Hipertensão Induzida pela Gravidez/induzido quimicamente , Artérias Mesentéricas/efeitos dos fármacos , Oligodesoxirribonucleotídeos/toxicidade , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/toxicidade , Animais , Inibidores de Ciclo-Oxigenase/farmacologia , Relação Dose-Resposta a Droga , Feminino , Idade Gestacional , Hipertensão Induzida pela Gravidez/fisiopatologia , Artérias Mesentéricas/fisiopatologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Gravidez , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Resistência Vascular/efeitos dos fármacos
18.
Cardiovasc Res ; 107(1): 119-30, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25910936

RESUMO

AIMS: Immune system activation is a common feature of hypertension pathogenesis. However, the mechanisms that initiate this activation are not well understood. Innate immune system recognition and response to danger are becoming apparent in many cardiovascular diseases. Danger signals can arise from not only pathogens, but also damage-associated molecular patterns (DAMPs). Our first hypothesis was that the DAMP, mitochondrial DNA (mtDNA), which is recognized by Toll-like receptor 9 (TLR9), is elevated in the circulation of spontaneously hypertensive rats (SHR), and that the deoxyribonuclease enzymes responsible for its degradation have decreased activity in SHR. Based on these novel SHR phenotypes, we further hypothesized that (i) treatment of SHR with an inhibitory oligodinucleotide for TLR9 (ODN2088) would lower blood pressure and that (ii) treatment of normotensive rats with a TLR9-specific CpG oligonucleotide (ODN2395) would cause endothelial dysfunction and increase blood pressure. METHODS AND RESULTS: We observed that SHR have elevated circulating mtDNA and diminished deoxyribonuclease I and II activity. Additionally, treatment of SHR with ODN2088 lowered systolic blood pressure. On the other hand, treatment of normotensive rats with ODN2395 increased systolic blood pressure and rendered their arteries less sensitive to acetylcholine-induced relaxation and more sensitive to norepinephrine-induced contraction. This dysfunctional vasoreactivity was due to increased cyclooxygenase and p38 mitogen-activated protein kinase activation, increased reactive oxygen species generation, and reduced nitric oxide bioavailability. CONCLUSION: Circulating mtDNA and impaired deoxyribonuclease activity may lead to the activation of the innate immune system, via TLR9, and contribute to elevated arterial pressure and vascular dysfunction in SHR.


Assuntos
DNA Mitocondrial/sangue , Hipertensão/fisiopatologia , Receptor Toll-Like 9/fisiologia , Animais , Pressão Sanguínea , Endotélio Vascular/fisiopatologia , Feminino , Hipertensão/etiologia , Imunidade Inata , Masculino , Óxido Nítrico/fisiologia , Oligodesoxirribonucleotídeos/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
19.
Am J Physiol Heart Circ Physiol ; 306(2): H184-96, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24163075

RESUMO

Low-grade systemic inflammation is a common manifestation of hypertension; however, the exact mechanisms that initiate this pathophysiological response, thereby contributing to further increases in blood pressure, are not well understood. Aberrant vascular inflammation and reactivity via activation of the innate immune system may be the first step in the pathogenesis of hypertension. One of the functions of the innate immune system is to recognize and respond to danger. Danger signals can arise from not only pathogenic stimuli but also endogenous molecules released following cell injury and/or death [damage-associated molecular patterns (DAMPs)]. In the short-term, activation of the innate immune system is beneficial in the vasculature by providing cytoprotective mechanisms and facilitating tissue repair following injury or infection. However, sustained or excessive immune system activation, such as in autoimmune diseases, may be deleterious and can lead to maladaptive, irreversible changes to vascular structure and function. An initial source of DAMPs that enter the circulation to activate the innate immune system could arise from modest elevations in peripheral vascular resistance. These stimuli could subsequently lead to ischemic- or pressure-induced events aggravating further cell injury and/or death, providing more DAMPs for innate immune system activation. This review will address and critically evaluate the current literature on the role of the innate immune system in hypertension pathogenesis. The role of Toll-like receptor activation on somatic cells of the vasculature in response to the release of DAMPs and the consequences of this activation on inflammation, vasoreactivity, and vascular remodeling will be specifically discussed.


Assuntos
Hipertensão/metabolismo , Receptores Toll-Like/metabolismo , Animais , Endotélio Vascular/imunologia , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Humanos , Hipertensão/etiologia , Hipertensão/imunologia , Imunidade Inata , Inflamação/imunologia , Inflamação/metabolismo , Músculo Liso Vascular/imunologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Receptores Toll-Like/imunologia
20.
J Hypertens ; 32(3): 542-54, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24309491

RESUMO

AIMS: Endogenous ouabain is elevated in patients and experimental models of hypertension and is associated with elevated mortality. In this context, it is reasonable to assume that a new antihypertensive drug that inhibits the deleterious effects of endogenous ouabain may be a specific pharmacological tool for hypertension treatment. Here, we investigated the effects of rostafuroxin (ROSTA), an ouabain inhibitor, on SBP, endothelial dysfunction and oxidative stress in deoxycorticosterone acetate (DOCA)-salt rats. METHODS AND RESULTS: A hypertensive model was established in uninephrectomized Wistar rats using DOCA-salt. After SBP stabilization, DOCA-salt rats were divided into two groups: DOCA-salt (control) and DOCA-salt treatment with ROSTA (1 mg/kg per day gavage, 3 weeks). The SBP was measured using the tail-cuff method, and vascular function was assessed in mesenteric-resistance arteries (MRAs) using a wire myograph. Nitric oxide and reactive oxygen species production were investigated. Western blot was performed to quantify protein expression. Our results indicated that ROSTA treatment decreased SBP, improved acetylcholine-induced relaxation via enhanced nitric oxide synthesis and bioavailability, decreased superoxide anion generation from NAD(P)H oxidase and cyclooxygenase-2 and reduced cytoplasmic tyrosine kinase Src phosphorylation without changes in NaKATPase activity in MRA from DOCA-salt rats. CONCLUSION: This study reports the critical role of endogenous ouabain in volume-dependent hypertension. In MRA from DOCA-salt rats, the binding of endogenous ouabain to NaK-ATPase results in downstream c-SRC activation, oxidative stress and endothelial dysfunction. Endogenous ouabain is a putative target for the treatment of hypertension, and ROSTA may represent a novel therapeutic approach.


Assuntos
Androstanóis/farmacologia , Anti-Hipertensivos/farmacologia , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Ouabaína/antagonistas & inibidores , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Ciclo-Oxigenase 2/metabolismo , Acetato de Desoxicorticosterona/toxicidade , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Humanos , Hipertensão/etiologia , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiopatologia , NADPH Oxidases/metabolismo , Ouabaína/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Cloreto de Sódio na Dieta/toxicidade , ATPase Trocadora de Sódio-Potássio/metabolismo , Resistência Vascular/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Quinases da Família src/metabolismo
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