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1.
Peptides ; 146: 170670, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34634392

RESUMO

Exercise reduces neuropathic pain in animals and humans. Recent studies indicate that training exercise favors the synthesis and action of angiotensin-(1-7) (Ang-(1-7)), a vasoactive peptide of the renin-angiotensin system (RAS), in various tissues. Interestingly, Ang-(1-7) also relieves neuropathic pain; however, it remains to be elucidated whether exercise mitigates this type of pain through Ang-(1-7). In this study, we investigated the role of Ang-(1-7) in exercise-induced analgesia in a neuropathic pain model. Male Wistar rats were ligated of lumbar spinal nerves (L5 and L6) or sham-operated. Then, they were subjected to acute (2-h) or chronic (4-week) exercise protocols. Tactile allodynia was evaluated before and after each exercise intervention. Microosmotic pumps were implanted subcutaneously for the release of Ang-(1-7) or A779 (selective Mas receptor (MasR; Ang-(1-7) receptor) antagonist). Plasma levels of Ang II and Ang-(1-7) were quantified by HPLC. Spinal nerve ligation (SNL) produced tactile allodynia. Both acute and chronic exercise reversed this neuropathic behavior. A779 treatment prevented the antiallodynic effect induced by each exercise protocol. SNL increased the plasma Ang II/Ang-(1-7) ratio; however, exercise did not modify it. Acute treatment with Ang-(1-7) via MasR mimicked exercise-mediated antinociception. Collectively, these results suggest that activation of the Ang-(1-7)/MasR axis of the RAS represents a potential novel mechanism by which exercise attenuates neuropathic pain in rats.


Assuntos
Analgesia , Angiotensina I/fisiologia , Neuralgia/fisiopatologia , Fragmentos de Peptídeos/fisiologia , Condicionamento Físico Animal , Animais , Hiperalgesia/prevenção & controle , Masculino , Ratos , Ratos Wistar
2.
Ann Biomed Eng ; 49(12): 3550-3562, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34704164

RESUMO

The renin-angiotensin system (RAS) is activated in aortic valve disease, yet little is understood about how it affects the acute functional response of valve interstitial cells (VICs). Herein, we developed a gelatin-based valve thin film (vTF) platform to investigate whether the contractile response of VICs can be regulated via RAS mediators and inhibitors. First, the impact of culture medium (quiescent, activated, and osteogenic medium) on VIC phenotype and function was assessed. Contractility of VICs was measured upon treatment with angiotensin I (Ang I), angiotensin II (Ang II), angiotensin-converting enzyme (ACE) inhibitor, and Angiotensin II type 1 receptor (AT1R) inhibitor. Anisotropic cell alignment on gelatin vTF was achieved independent of culture conditions. Cells cultured in activated and osteogenic conditions were found to be more elongated than in quiescent medium. Increased α-SMA expression was observed in activated medium and no RUNX2 expression were observed in cells. VIC contractile stress increased with increasing concentrations (from 10-10 to 10-6 M) of Ang I and Ang II. Moreover, cell contraction was significantly reduced in all ACE and AT1R inhibitor-treated groups. Together, these findings suggest that local RAS is active in VICs, and our vTF may provide a powerful platform for valve drug screening and development.


Assuntos
Valva Aórtica/citologia , Sistema Renina-Angiotensina/fisiologia , Angiotensina I/farmacologia , Angiotensina I/fisiologia , Angiotensina II/farmacologia , Angiotensina II/fisiologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Valva Aórtica/efeitos dos fármacos , Células Cultivadas , Imunofluorescência , Losartan/farmacologia , Miofibroblastos/fisiologia , Peptidil Dipeptidase A/fisiologia , Receptor Tipo 1 de Angiotensina/fisiologia , Suínos , Tetra-Hidroisoquinolinas/farmacologia
3.
Transl Res ; 235: 62-76, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33915312

RESUMO

G protein-coupled estrogen receptor (GPER) activation by G1 attenuates diastolic dysfunction from estrogen loss, which may be partly due to suppression of angiotensin II pathological actions. We aimed to determine the independent effects of 8 weeks of G1 (100 µg/kg/d, subcutaneous pellet), ACE-inhibition (ACEi; lisinopril 10 mg/kg, drinking water), or combination therapy versus vehicle in the ovariectomized (OVX) spontaneously hypertensive rat (SHR) on cardiac function and morphometrics (echocardiography), serum equilibrium of angiotensins (mass spectroscopy) and cardiac components of the RAS (Western blotting). G1 alone and when combined with ACEi enhanced myocardial relaxation (é: 30 and 17%) and diastolic wall strain (DWS: 76 and 68%) while reducing relative wall thickness (RWT: 20 and 33%) and filling pressures (E/é: 30 and 37%). Cardiac expression levels of Mas receptor (Mas-R) and ACE2 also increased in the presence of G1. Strong antihypertensive effects of lisinopril monotherapy were associated with reductions in RWT, collagen deposition and E/é without overtly altering é or DWS. Chronic ACEi also increased cardiac levels of Mas-R and AT1-R and tilted the circulating RAS toward the formation of Ang-(1-7), which was amplified in the presence of G1. In vitro studies further revealed that an inhibitor to prolyl endopeptidase (PEP), but not to neprilysin, significantly reduced serum Ang-(1-7) levels in G1-treated rats, suggesting that G1 might be increasing Ang-(1-7) formation via PEP. We conclude that activating GPER with G1 augments components of the cardiac RAS and improves diastolic function without lowering blood pressure, and that lisinopril-induced blood pressure control and cardiac alterations in OVX SHR are permissive in facilitating G1 to augment Ang-(1-7) in serum, thereby strengthening its cardioprotective benefits.


Assuntos
Angiotensina I/fisiologia , Ciclopentanos/farmacologia , Diástole/efeitos dos fármacos , Lisinopril/farmacologia , Fragmentos de Peptídeos/fisiologia , Quinolinas/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Angiotensina I/sangue , Animais , Feminino , Ovariectomia , Fragmentos de Peptídeos/sangue , Ratos , Ratos Endogâmicos SHR , Receptores Acoplados a Proteínas G/fisiologia , Sistema Renina-Angiotensina/efeitos dos fármacos , Sistema Renina-Angiotensina/fisiologia
5.
J Renin Angiotensin Aldosterone Syst ; 21(4): 1470320320972018, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33169644

RESUMO

In the wake of the COVID-19 pandemic it has become clear that there is a need for therapies that are capable of reducing damage caused to patients from infections. Infections that induce Acute Respiratory Distress Syndrome (ARDS) are especially devastating because lung damage is so critical and difficult to manage. Angiotensin (1-7) [A(1-7)] has already been shown to protect pulmonary health and architecture in various models of disease. There is also evidence that A(1-7) can modulate immune function and protect various organs (lung, kidney, and heart) from oxidative damage and inflammation. Here we focus on making a case for the development of novel therapies that target the protective arm of the Renin Angiotensin System (RAS).


Assuntos
Angiotensina I/uso terapêutico , Betacoronavirus/fisiologia , Infecções por Coronavirus/complicações , Fragmentos de Peptídeos/uso terapêutico , Pneumonia Viral/complicações , Síndrome do Desconforto Respiratório/tratamento farmacológico , Síndrome do Desconforto Respiratório/virologia , Angiotensina I/fisiologia , Enzima de Conversão de Angiotensina 2 , Animais , COVID-19 , Infecções por Coronavirus/mortalidade , Humanos , Pandemias , Fragmentos de Peptídeos/fisiologia , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/mortalidade , Sistema Renina-Angiotensina/efeitos dos fármacos , Sistema Renina-Angiotensina/fisiologia , SARS-CoV-2
7.
Circ Heart Fail ; 13(7): e006939, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32580658

RESUMO

BACKGROUND: ACE2 (angiotensin-converting enzyme 2) and Ang 1-7 (angiotensin 1-7) are endogenous negative regulators of the renin-angiotensin system exerting cardioprotective effects in models of heart failure. Recombinant human ACE2 markedly increased plasma Ang 1-7 and lowered Ang II levels in phase II clinical trials. We hypothesize that the dynamic state of this renin-angiotensin system protective arm could influence long-term outcomes in patients with heart failure. METHODS: One hundred ten patients with heart failure were prospectively enrolled from our outpatient clinic and the emergency department. Comprehensive circulating and equilibrium levels of plasma angiotensin peptide profiles were assessed using novel liquid chromatography-mass spectrometry/mass spectroscopy techniques. Plasma aldosterone, B-type natriuretic peptide, active renin concentration, and clinical profiles were captured at baseline. During a median follow-up of 5.1 years (interquartile range, 4.7-5.7 years), composite clinical outcomes were assessed using all-cause in-patient hospitalizations and mortality. RESULTS: Circulating and equilibrium angiotensin peptide levels strongly correlated in our patient cohort. Adjusting for covariates, elevated equilibrium (hazard ratio, 0.38 [95% CI, 0.18-0.81] P=0.012), and circulating (hazard ratio, 0.38 [95% CI, 0.18-0.80] P=0.011) Ang 1-7/Ang II ratios were associated with improved survival. Lower hospitalization duration was also associated with elevated equilibrium (P<0.001) and circulating (P=0.023) Ang 1-7/Ang II ratios. Importantly, individual Ang 1-7 and Ang II peptide levels failed to predict all-cause mortality or hospitalization duration in our patient cohort. CONCLUSIONS: We extensively profiled plasma angiotensin peptides in patients with heart failure and identified elevated Ang 1-7/Ang II ratio, as an independent and incremental predictor of beneficial outcomes, higher survival rate, and decreased hospitalization duration. These findings provide important clinical evidence supporting strategies aiming to promote the beneficial Ang 1-7/Mas axis concurrent with renin-angiotensin system blockade therapies inhibiting the detrimental Ang II/AT1 receptor axis.


Assuntos
Angiotensina II/sangue , Angiotensina I/sangue , Insuficiência Cardíaca/sangue , Fragmentos de Peptídeos/sangue , Idoso , Idoso de 80 Anos ou mais , Angiotensina I/fisiologia , Angiotensina II/fisiologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Biomarcadores/sangue , Feminino , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Fragmentos de Peptídeos/fisiologia , Estudos Prospectivos , Sistema Renina-Angiotensina/efeitos dos fármacos , Sistema Renina-Angiotensina/fisiologia
10.
J Eur Acad Dermatol Venereol ; 34(3): 558-564, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31746507

RESUMO

BACKGROUND: Systemic sclerosis (SSc) is a multisystemic disease with an extensive microvasculopathy. Previously, disturbances in plasma levels of angiotensin II (Ang II) and its antagonistic angiotensin-(1-7) (Ang-(1-7)) were found in patients with SSc. Their significance in a pathogenesis of SSc stays unclear due to discrepancies of earlier studies. OBJECTIVES: To evaluate a significance of disturbances in production pathway of angiotensins in a development of SSc. METHODS: There were enrolled 27 patients with established SSc, 23 subjects with very early SSc and 23 healthy controls. The diagnosis of SSc was established in patients who met EULAR/ACR 2013 classification criteria. Very early SSc described patients with Raynaud's phenomenon having SSc-specific antinuclear antibodies and SSc-like abnormalities in nailfold videocapillaroscopy. Patients were submitted to evaluation of internal organ involvement and blood sampling to assay plasma levels of angiotensin I, angiotensin II and angiotensin-(1-7) with ELISA technique. RESULTS: Plasma level of angiotensin-(1-7) was significantly reduced in both SSc group (median = 47.2 pg/mL; P < 0.001) and ones with very early SSc (median = 102.7 pg/mL; P = 0.002) when compared to healthy controls (median = 176.1 pg/mL). A tendency to higher than in control group (median = 214 pg/mL) plasma level of angiotensin I was seen in SSc group (median = 392 pg/mL; P = 0.059). Differences in plasma level of angiotensin II were insignificant between all study groups. Those disturbances produced unfavourable angiotensin-(1-7)/angiotensin II (%) ratio in both groups of patients, which achieved statistical significance in subjects with established SSc (P < 0.001). Production pathway of angiotensins showed a dependence on a subtype of SSc, immune profile and a presence of interstitial lung disease. CONCLUSIONS: Production of angiotensin-(1-7) was significantly reduced in both SSc patients and those ones with very early SSc, although a significant imbalance between angiotensin II and angiotensin-(1-7) occurred only in subjects with established disease.


Assuntos
Angiotensina II/fisiologia , Angiotensina I/fisiologia , Fragmentos de Peptídeos/fisiologia , Escleroderma Sistêmico/etiologia , Adulto , Idoso , Angiotensina I/sangue , Angiotensina II/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/sangue , Escleroderma Sistêmico/sangue , Adulto Jovem
12.
Peptides ; 108: 25-33, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30179652

RESUMO

Evidence suggests that the renin angiotensin system (RAS) may play a role in the pathological splanchnic vasodilatation that leads to a hyperdynamic circulation in cirrhosis. An impaired contractile response to the angiotensin II peptide of the classical RAS system has been described in animal models of cirrhosis and in vivo in cirrhotic subjects. Furthermore, in experimental cirrhosis, the so-called alternate arm of the RAS was found to be upregulated and its effector peptide, angiotensin-(1-7) was shown to attenuate splanchnic vascular tone. The aim of this study was to explore the relevance of these findings to human disease. Omental arteries from cirrhotic and controls subjects were studied in isolation using a wire myograph. Varied protocols to evaluate the vasoactivity of RAS mediators were enacted. The contractile response to angiotensin II was comparable in cirrhotic vs control splanchnic arteries (61 ± 9 vs 68 ± 11% KPSS, respectively). Despite this, however, arterial contractility of the cirrhotic vessels correlated negatively with Child Pugh score (p = 0.0003, r=-0.83) and there was evidence that angiotensin II-induced contractility was increased in early cirrhosis. Angiotensin II-induced contractility was attenuated by angiotensin-(1-7) in cirrhotic and control arteries, however, adrenergic responses were not affected by angiotensin-(1-7). Contractile responses to angiotensin II are preserved in narrow lumen human cirrhotic splanchnic arteries and are comparatively augmented in early disease. Angiotensin-(1-7) had no vasodilatory effect on adrenergic tone, however, attenuated angiotensin II-induced contractility, possibly through an Ang-(1-7)-AT1R interaction, and thus may contribute to pathological vasodilatation in human cirrhosis.


Assuntos
Angiotensina II/fisiologia , Angiotensina I/fisiologia , Cirrose Hepática/metabolismo , Omento/irrigação sanguínea , Fragmentos de Peptídeos/fisiologia , Vasodilatação , Feminino , Humanos , Hipertensão Portal , Cirrose Hepática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Sistema Renina-Angiotensina
13.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 43(7): 738-746, 2018 Jul 28.
Artigo em Chinês | MEDLINE | ID: mdl-30124209

RESUMO

OBJECTIVE: To investigate changes in the angiotensin converting enzyme 2 (ACE2) and angiotensin (1-7) [Ang (1-7)] and to explore the role of ACE2-Ang (1-7)-Mas receptor axis in hypertension with heart failure with preserved ejection fraction (HFPEF).
 Methods: A total of 70 patients with primary hypertension and preserved left ventricular ejection fraction (LVEF>50%) were recruited and patients were divided into a hypertension group (HBP) and a heart failure with preserved ejection fraction group (HFpEF) according to the diagnostic criteria of HFpEF. Thirty-five healthy participants were selected randomly as a control group. Enzyme linked immunosorbent assays (ELISA) method was used to detect concentration of Ang (1-7), ACE2, angiotensin II (Ang II), brain natriuretic peptide (BNP) in plasma. Male Sprague- Dawley (SD) rats was randomly divided into 2 groups: An HFpEF group (n=16) and a sham group (n=8). Rats (n=8) in the AAC group were given Ang (1-7) [0.5 mg/(kg.d), intraperitoneally] for 6 weeks, and the rest were given equal dose normal saline. Then all the rats were killed, and the hearts were taken out for hematoxylineosin (HE) staining. The protein expressions of angiotensin converting enzyme (ACE), ACE2, and Mas receptor were detected by Western blot.
 Results: The BNP and Ang II were significantly increased in the HBP group and the HFpEF group compared with the control group (P<0.01). There were not significantly different in levels of ACE2 and Ang (1-7) between the HBP group and control group (P>0.05), whereas those levels were significantly increased in the HFpEF group compared with the HBP group and control group (P<0.01). HE staining showed obvious hypertrophy of myocardial cell in the AAC group compared with the sham group. Hypertrophy of myocardial cell in the AAC+Ang (1-7) group was significantly higher than that in the AAC group. Expressions of ACE, ACE2, and Mas receptor proteins were significantly higher in the AAC group than those in the sham group (P<0.05), while the expressions of ACE2 and Mas receptor proteins in the AAC+Ang (1-7) group were significantly higher than those in the AAC group (P<0.05). There was no significant difference in the ACE protein expression between groups (P>0.05).
 Conclusion: ACE2 and Ang (1-7) are important predictive factors for the severity of heart failure and myocardial remodeling of HFpEF with hypertension; ACE2-Ang (1-7)-Mas receptor axis may play a protective role in preventing myocardial remodeling in HFpEF with hypertension.


Assuntos
Angiotensina I/fisiologia , Insuficiência Cardíaca/metabolismo , Hipertensão/metabolismo , Fragmentos de Peptídeos/fisiologia , Peptidil Dipeptidase A/fisiologia , Angiotensina II , Enzima de Conversão de Angiotensina 2 , Animais , Remodelamento Atrial/fisiologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Insuficiência Cardíaca/fisiopatologia , Humanos , Hipertensão/fisiopatologia , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/fisiologia , Volume Sistólico , Função Ventricular Esquerda/fisiologia , Remodelação Ventricular/fisiologia
14.
Clin Sci (Lond) ; 132(10): 1021-1038, 2018 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-29802208

RESUMO

All the components of the classic renin-angiotensin system (RAS) have been identified in the brain. Today, the RAS is considered to be composed mainly of two axes: the pressor axis, represented by angiotensin (Ang) II/angiotensin-converting enzyme/AT1 receptors, and the depressor and protective one, represented by Ang-(1-7)/ angiotensin-converting enzyme 2/Mas receptors. Although the RAS exerts a pivotal role on electrolyte homeostasis and blood pressure regulation, their components are also implicated in higher brain functions, including cognition, memory, anxiety and depression, and several neurological disorders. Overactivity of the pressor axis of the RAS has been implicated in stroke and several brain disorders, such as cognitive impairment, dementia, and Alzheimer or Parkinson's disease. The present review is focused on the role of the protective axis of the RAS in brain disorders beyond its effects on blood pressure regulation. Furthermore, the use of drugs targeting centrally RAS and its beneficial effects on brain disorders are also discussed.


Assuntos
Encefalopatias/fisiopatologia , Sistema Renina-Angiotensina/fisiologia , Doença de Alzheimer/fisiopatologia , Angiotensina I/fisiologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Ansiedade/fisiopatologia , Encefalopatias/prevenção & controle , Cognição/fisiologia , Humanos , Fragmentos de Peptídeos/fisiologia , Sistema Renina-Angiotensina/efeitos dos fármacos , Acidente Vascular Cerebral/fisiopatologia , Pesquisa Translacional Biomédica/métodos
15.
Clin Sci (Lond) ; 132(11): 1117-1133, 2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29685981

RESUMO

Patients with hyperthyroidism exhibit increased risk of development and progression of cardiac diseases. The activation of the renin-angiotensin system (RAS) has been indirectly implicated in these cardiac effects observed in hyperthyroidism. Angiotensin-(1-7) (Ang-(1-7)) has previously been shown to counterbalance pathological effects of angiotensin II (Ang II). The aim of the present study was to investigate the effects of elevated circulating Ang-(1-7) levels on cardiac effects promoted by hyperthyroidism in a transgenic rat (TG) model that constitutively overexpresses an Ang-(1-7)-producing fusion protein [TGR(A1-7)3292]. TG and wild-type (WT) rats received daily injections (i.p.) of triiodothyronine (T3; 7 µg/100 g of body weight (BW)) or vehicle for 14 days. In contrast with WT rats, the TG rats did not develop cardiac hypertrophy after T3 treatment. Indeed, TG rats displayed reduced systolic blood pressure (SBP) and cardiac hyperdynamic condition induced by hyperthyroidism. Moreover, increased plasma levels of Ang II observed in hyperthyroid WT rats were prevented in TG rats. TG rats were protected from glycogen synthase kinase 3ß (GSK3ß) inactivation and nuclear factor of activated T cells (NFAT) nuclear accumulation induced by T3. In vitro studies evidenced that Ang-(1-7) prevented cardiomyocyte hypertrophy and GSK3ß inactivation induced by T3. Taken together, these data reveal an important cardioprotective action of Ang-(1-7) in experimental model of hyperthyroidism.


Assuntos
Angiotensina I/fisiologia , Cardiomegalia/etiologia , Glicogênio Sintase Quinase 3 beta/fisiologia , Hipertireoidismo/complicações , Fatores de Transcrição NFATC/fisiologia , Fragmentos de Peptídeos/fisiologia , Angiotensina I/sangue , Angiotensina I/farmacologia , Animais , Cardiomegalia/sangue , Cardiomegalia/diagnóstico por imagem , Células Cultivadas , Ecocardiografia , Hipertireoidismo/sangue , Hipertireoidismo/induzido quimicamente , Masculino , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/farmacologia , Ratos Sprague-Dawley , Ratos Transgênicos , Ratos Wistar , Sistema Renina-Angiotensina/fisiologia , Transdução de Sinais/fisiologia , Tri-Iodotironina/farmacologia
16.
Chin J Integr Med ; 24(11): 853-859, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29335866

RESUMO

OBJECTIVE: To explore the effect of Biejiajian Oral Liquid (, BOL) on CCl4-induced hepatic fibrosis in rats by detecting the changes in the levels of angiotensin II (Ang II), angiotensin-(1-7) [Ang-(1-7)], angiotensin-converting enzyme (ACE), ACE2, angiotensin II type 1 receptor (AT1R), Mas, etc. METHODS: A total of 180 Wistar rats were randomly divided into two groups by random digital table method: prevention experiment and treatment experiment. Each group was further subdivided into the following 6 subgroups: normal control group, model group, vitamin E [100 mg/(kg·d), VE] group, enalapril [10 mg/(kg·g), Ena] group, high-dosage [20 g/(kg·d)] BOL group, and low-dosage [10 g/(kg·d)] BOL group. The hepatic fibrosis rat model was established by subcutaneous injection of CCl4 for 6 weeks. Prevention experiment and treatment experiment were administered with specific drugs at different times. At the end of treatment experiment, the pathological changes of liver were observed after hematoxylin-eosin staining. The expressions of ingredients in renin-angiotensin-aldosterone system (RAAS) such as AngII, Ang-(1-7), ACE, ACE2, AT1R, Mas, renin, CYP11B2 and angen in liver were detected by enzyme linked immunosorbent assay, immunohistochemistry method or reverse transcription-polymerase chain reaction, respectively. RESULTS: The levels of AngII and Ang-(1-7) at the 6th week increased by 496.10% and 73.64%, respectively, compared with those at the 2nd week in the model group (P<0.01). With prevention or treatment with high-dosage BOL, there was an evident reduction of AngII level but an improvement of Ang-(1-7) level. Specifically, AngII level of high-dosage group decreased by 77.50% in prevention experiment (P=0.000) and by 76.93% in treatment experiment (P=0.002) compared with that in the model group. Ang-(1-7) level increased by 91.69% in prevention experiment (P=0.006) and by 70.77% in the treatment experiment (P=0.010) compared with that in the model group. The expression levels of mRNA of renin, ACE, CYP11B2, angen and AT1R decreased by 58.15%, 99.90%, 99.84%, 99.99% and 99.99% (all P<0.01), respectively. CONCLUSIONS: BOL could help resist liver fibrosis in rats by enhancing the level of each ingredient in ACE2-Ang-(1-7)-Mas axis, while decreasing the level of each ingredient in ACE-AngII-AT1R axis. To some extent, BOL could enhance the regulation of RAAS in rats with CCl4-induced hepatic fibrosis.


Assuntos
Angiotensina II/fisiologia , Angiotensina I/fisiologia , Medicamentos de Ervas Chinesas/uso terapêutico , Cirrose Hepática Experimental/tratamento farmacológico , Fragmentos de Peptídeos/fisiologia , Peptidil Dipeptidase A/fisiologia , Receptor Tipo 1 de Angiotensina/fisiologia , Administração Oral , Enzima de Conversão de Angiotensina 2 , Animais , Tetracloreto de Carbono , Cirrose Hepática Experimental/fisiopatologia , Masculino , Ratos , Ratos Wistar
17.
Metabolism ; 81: 83-96, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29225087

RESUMO

OBJECTIVE: Angiotensin-converting enzyme 2 (ACE2) has been identified in pancreatic islets and can preserve ß cells. In this study, we aimed to examine the possible role of ACE2 and its end product, angiotensin 1-7 (A1-7), in reducing ß cell dedifferentiation during metabolic stress. METHODS: First, a lineage-tracing experiment was performed to track ß cells in mice fed a high-fat diet (HFD). Second, the ACE2/A1-7 axis was evaluated in the HFD mouse model. Intraperitoneal glucose tolerance tests (IPGTTs) and intraperitoneal insulin tolerance tests (IPITTs) were conducted. Phenotypic changes in ß cells were detected by immunohistochemistry and quantitative real-time PCR. Pancreatic sections were immunostained for vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS). Finally, the effects of the ACE2/A1-7 axis were explored in isolated mouse islets exposed to different concentrations of glucose. Glucose-stimulated insulin release and levels of insulin mRNA and OCT4 mRNA were measured. RESULTS: Pancreatic ß cell dedifferentiation occurred both in vitro and in vivo in response to metabolic stress and was accompanied by ACE2 reduction. HFD-induced insulin resistance and glucose intolerance were exacerbated in ACE2-knockout (ACE2KO) mice but were alleviated by exogenous A1-7 in C57BL/6J mice. Approximately 20% of ß cells were dedifferentiated in ACE2KO mice fed a standard rodent chow diet (SD). A higher percentage of dedifferentiated ß cells was detected in ACE2KO mice than in wild-type (WT) mice under HFD conditions. In contrast, the administration of A1-7 alleviated HFD-induced ß cell dedifferentiation in C57BL/6J mice. Moreover, the exogenous injection of A1-7 improved microcirculation in islets and decreased the production of iNOS in islets of C57BL/6J mice fed an HFD. Additionally, ACE2 was found to be mainly expressed in α cells of mice, while Mas, the receptor of A1-7, was distributed in ß cells. CONCLUSIONS: Overall, this study is the first to demonstrate that the ACE2/A1-7/Mas axis may be one of the intra-islet paracrine mechanisms of communication between α and ß cells. Enhancing the ACE2/A1-7 axis exerts a protective effect by ameliorating ß cell dedifferentiation, and this effect might be partially mediated through improvements in islet microcirculation and suppression of islet iNOS.


Assuntos
Angiotensina I/fisiologia , Desdiferenciação Celular , Células Secretoras de Insulina/citologia , Fragmentos de Peptídeos/fisiologia , Peptidil Dipeptidase A/fisiologia , Enzima de Conversão de Angiotensina 2 , Animais , Linhagem da Célula , Dieta Hiperlipídica , Intolerância à Glucose/etiologia , Insulina/genética , Insulina/metabolismo , Resistência à Insulina , Secreção de Insulina , Células Secretoras de Insulina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Aumento de Peso
18.
Protein Pept Lett ; 24(9): 809-816, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-28758593

RESUMO

BACKGROUND: Many physiological responses of the Renin Angiotensin System (RAS) are associated with two opposite pathways: (1) a classical one formed by angiotensin-converting enzyme (ACE), Angiotensin II (Ang II) and Angiotensin type 1 (AT1) receptor, which is associated to vasoconstriction, cell proliferation, organ hypertrophy, sodium retention and aldosterone release and (2) a counter-regulatory or vasodilator pathway comprising angiotensin-converting enzyme 2 (ACE2), Angiotensin-(1-7) [Ang-(1-7)] and Mas receptor, which is involved in vasodilation, antiproliferation, anti-hypertrophy, cardioprotective and renoprotective actions. OBJECTIVE: This review aimed to bring up-to-date on the interactions between physical exercise and the vasodilator axis of the RAS (ACE2-Ang-(1-7)-Mas receptor axis). We also investigated the relation of acute and chronic exercise with blood pressure regulation and components of the vasodilator axis of the RAS. METHODS: We searched studies with animal models and humans in PUBMED, LILACS and IBECS. RESULTS: Experimental studies showed that physical training can stimulate ACE2-Ang-(1-7)-Mas receptor axis in parallel with the inhibition of ACE-Ang II-AT1 receptor pathway. However, up to now, the interaction between the counter-regulatory RAS axis and physical training is not investigated in humans. CONCLUSION: The activation of ACE2-Ang-(1-7)-Mas receptor axis may have a role in the beneficial effects of physical training in experimental models. Further studies with humans are necessary.


Assuntos
Angiotensina I/fisiologia , Exercício Físico/fisiologia , Fragmentos de Peptídeos/fisiologia , Peptidil Dipeptidase A/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Sistema Renina-Angiotensina/fisiologia , Angiotensina II/fisiologia , Enzima de Conversão de Angiotensina 2 , Animais , Humanos , Peptidil Dipeptidase A/metabolismo , Condicionamento Físico Animal/fisiologia , Proto-Oncogene Mas , Transdução de Sinais , Vasoconstrição/fisiologia
19.
Diabetes ; 66(8): 2201-2212, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28559246

RESUMO

Recent work has renewed interest in therapies targeting the renin-angiotensin system (RAS) to improve ß-cell function in type 2 diabetes. Studies show that generation of angiotensin-(1-7) by ACE2 and its binding to the Mas receptor (MasR) improves glucose homeostasis, partly by enhancing glucose-stimulated insulin secretion (GSIS). Thus, islet ACE2 upregulation is viewed as a desirable therapeutic goal. Here, we show that, although endogenous islet ACE2 expression is sparse, its inhibition abrogates angiotensin-(1-7)-mediated GSIS. However, a more widely expressed islet peptidase, neprilysin, degrades angiotensin-(1-7) into several peptides. In neprilysin-deficient mouse islets, angiotensin-(1-7) and neprilysin-derived degradation products angiotensin-(1-4), angiotensin-(5-7), and angiotensin-(3-4) failed to enhance GSIS. Conversely, angiotensin-(1-2) enhanced GSIS in both neprilysin-deficient and wild-type islets. Rather than mediating this effect via activation of the G-protein-coupled receptor (GPCR) MasR, angiotensin-(1-2) was found to signal via another GPCR, namely GPCR family C group 6 member A (GPRC6A). In conclusion, in islets, intact angiotensin-(1-7) is not the primary mediator of beneficial effects ascribed to the ACE2/angiotensin-(1-7)/MasR axis. Our findings warrant caution for the concurrent use of angiotensin-(1-7) compounds and neprilysin inhibitors as therapies for diabetes.


Assuntos
Angiotensina I/fisiologia , Angiotensinas/metabolismo , Insulina/metabolismo , Neprilisina/deficiência , Fragmentos de Peptídeos/fisiologia , Sistema Renina-Angiotensina/fisiologia , Enzima de Conversão de Angiotensina 2 , Animais , Glucose/fisiologia , Secreção de Insulina , Células Secretoras de Insulina/enzimologia , Células Secretoras de Insulina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neprilisina/fisiologia , Peptidil Dipeptidase A/metabolismo , Proteólise , Receptores Acoplados a Proteínas G/fisiologia , Transdução de Sinais
20.
Peptides ; 92: 16-22, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28438644

RESUMO

The angiotensin (Ang) converting enzyme 2/Ang-(1-7)/Mas axis has been described to have a beneficial role on metabolic disorders. In the present study, the use of a transgenic rat model that chronically overexpresses Ang-(1-7) enabled us to investigate the chronic effects of this peptide on lipid accumulation in the liver and adipose tissue. The transgenic group showed a marked tendency toward increased expression of peroxisome proliferator-activated receptor-γ (PPARγ) and decreased lipoprotein lipase (LPL) expression and activity in epididymal adipose tissue. We also showed that Mas receptor-knockout mice had decreased PPARγ expression in adipose tissue, accompanied by an increase in LPL activity. These results confirm the regulation of adipose tissue LPL activity by Ang-(1-7) and suggest that this occurs independent of PPARγ expression. The reduced adiposity index of transgenic rats, due to the effect of Ang-(1-7), was accompanied by a decrease in lipogenesis. These findings suggest a direct effect of Ang-(1-7) on lipogenesis, independent of the stimulatory effect of insulin. Furthermore, the decreased concentration of triacylglycerol in the liver of transgenic rats may result from increased activity of cytosolic lipases and decreased fatty acid uptake from the adipose tissue, determined from fatty acid-binding protein expression, and hepatic de novo fatty acid synthesis, evaluated by fatty acid synthase expression. The data clearly show that Ang-(1-7) regulates lipid metabolism in the adipose tissue and liver.


Assuntos
Tecido Adiposo/metabolismo , Angiotensina I/fisiologia , Metabolismo dos Lipídeos , Fígado/metabolismo , Fragmentos de Peptídeos/fisiologia , Adiposidade , Angiotensina I/genética , Animais , Ácidos Graxos/metabolismo , Hipertensão/metabolismo , Insulina/metabolismo , Lipase Lipoproteica/genética , Lipase Lipoproteica/metabolismo , Masculino , Camundongos , Obesidade/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Fragmentos de Peptídeos/genética , RNA Mensageiro/genética , Ratos , Ratos Transgênicos , Fatores de Tempo , Triglicerídeos/metabolismo
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