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1.
J Cell Sci ; 133(13)2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32482794

RESUMO

Arterial remodeling in hypertension and intimal hyperplasia involves inflammation and disrupted flow, both of which contribute to smooth muscle cell dedifferentiation and proliferation. In this context, our previous results identified phosphoinositide 3-kinase γ (PI3Kγ) as an essential factor in inflammatory processes of the arterial wall. Here, we identify for the first time a kinase-independent role of nonhematopoietic PI3Kγ in the vascular wall during intimal hyperplasia using PI3Kγ-deleted mice and mice expressing a kinase-dead version of the enzyme. Moreover, we found that the absence of PI3Kγ in vascular smooth muscle cells (VSMCs) leads to modulation of cell proliferation, associated with an increase in intracellular cAMP levels. Real-time analysis of cAMP dynamics revealed that PI3Kγ modulates the degradation of cAMP in primary VSMCs independently of its kinase activity through regulation of the enzyme phosphodiesterase 4. Importantly, the use of an N-terminal competing peptide of PI3Kγ blocked primary VSMC proliferation. These data provide evidence for a kinase-independent role of PI3Kγ in arterial remodeling and reveal novel strategies targeting the docking function of PI3Kγ for the treatment of cardiovascular diseases.


Assuntos
Fosfatidilinositol 3-Quinase , Fosfatidilinositol 3-Quinases , Animais , Artérias , Proliferação de Células , Camundongos , Miócitos de Músculo Liso , Fosfatidilinositol 3-Quinases/genética
2.
Biochim Biophys Acta Mol Cell Res ; 1865(9): 1326-1340, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29940197

RESUMO

Here, we cloned a new family of four adenylyl cyclase (AC) splice variants from interleukin-1ß (IL-1ß)-transdifferentiated vascular smooth muscle cells (VSMCs) encoding short forms of AC8 that we have named "AC8E-H". Using biosensor imaging and biochemical approaches, we showed that AC8E-H isoforms have no cyclase activity and act as dominant-negative regulators by forming heterodimers with other full-length ACs, impeding the traffic of functional units towards the plasma membrane. The existence of these dominant-negative isoforms may account for an unsuspected additional degree of cAMP signaling regulation. It also reconciles the induction of an AC in transdifferentiated VSMCs with the vasoprotective influence of cAMP. The generation of alternative splice variants of ACs may constitute a generalized strategy of adaptation to the cell's environment whose scope had so far been ignored in physiological and/or pathological contexts.


Assuntos
Adenilil Ciclases/genética , Adenilil Ciclases/metabolismo , Processamento Alternativo , AMP Cíclico/metabolismo , Interleucina-1beta/farmacologia , Músculo Liso Vascular/citologia , Adenilil Ciclases/química , Animais , Transdiferenciação Celular , Células Cultivadas , Clonagem Molecular , Retículo Endoplasmático Rugoso/metabolismo , Células HEK293 , Humanos , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Multimerização Proteica , Ratos
3.
FASEB J ; 32(9): 4972-4983, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29620941

RESUMO

Cerebral amyloid angiopathy (CAA) is a major contributor to Alzheimer's disease (AD) pathogenesis. Like AD, CAA is often accompanied by marked inflammation, aggravating associated vasculopathies. No evidence-based prevention or treatment strategies are available. Here, we evaluate the possible beneficial effect of a diet enriched with docosahexaenoic acid (DHA), which is known to attenuate inflammation in CAA. Tg2576 mice, a transgenic model of AD/CAA, were fed a DHA-enriched diet starting at 2 mo of age and ending at 10, 14, or 18 mo of age. ß-Amyloid (Aß)-peptide deposition and bleeding were visualized by immunohistochemistry or histochemistry on coronal sections of the brain. DHA, arachidonic acid, and eicosanoid levels were measured by liquid chromatography/mass spectrometry or GC-MS. DHA-enriched diet throughout aging limits the accumulation of vascular Aß peptide deposits as well as the likelihood of microhemorrhages. There is a strong correlation between systemic 12-hydroxyeicosatetraenoic acid (HETE) levels and the size of the area affected by both vascular amyloid deposits and hemorrhages. The lowest levels of 12-HETE, a lipid-derived proinflammatory product of 12-lipoxygenase (LOX), were found in DHA-fed mice. In vitro experiments performed on amyloid vascular smooth muscle cells showed that a 12-LOX inhibitor almost completely blocked the Aß1-40 peptide-induced apoptosis of these cells. This study yet again highlights the important role of inflammation in CAA pathogenesis and identifies potential new targets for preventive care.-Hur, J., Mateo, V., Amalric, N., Babiak, M., Béréziat, G., Kanony-Truc, C., Clerc, T., Blaise, R., Limon, I. Cerebrovascular ß-amyloid deposition and associated microhemorrhages in a Tg2576 Alzheimer mouse model are reduced with a DHA-enriched diet.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Dieta/efeitos adversos , Ácidos Docosa-Hexaenoicos/farmacologia , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Angiopatia Amiloide Cerebral/tratamento farmacológico , Modelos Animais de Doenças , Camundongos Transgênicos , Miócitos de Músculo Liso/metabolismo
4.
Biochim Biophys Acta ; 1853(12): 3235-47, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26403276

RESUMO

Atherosclerosis development is associated with morphological changes to intimal cells, leading to a stellate cell phenotype. In this study, we aimed to determine whether and how key pro-atherogenic cytokines present in atherosclerotic plaques (IL-1ß, TNFα and IFNγ) could induce this phenotype, as these molecules are known to trigger the transdifferentiation of vascular smooth muscle cells (VSMCs). We found that, IL-1ß was the only major inflammatory mediator tested capable of inducing a stellate morphology in VSMCs. This finding was confirmed by staining for F-actin and vinculin at focal adhesions, as these two markers were disrupted only by IL-1ß. We then investigated the possible association of this IL-1ß-dependent change in morphology with an increase in intracellular cAMP concentration ([cAMP]), using the FRET-based biosensor for cAMP (T)Epac(VV). Experiments in the presence of IL-1ß or medium conditioned by IL-1ß-treated VSMCs and pharmacological tools demonstrated that the long-term increase in intracellular cAMP concentration was induced by the secretion of an autocrine/paracrine mediator, prostaglandin E2(PGE2), acting through the EP4 receptor. Finally, by knocking down the expression of the regulatory subunit PKAR1α, thereby reproducing the effects of IL-1ß and PGE2 on VSMCs, we demonstrated the contribution of PKA activity to the observed behavior of VSMCs.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Interleucina-1beta/metabolismo , Músculo Liso Vascular/citologia , Animais , Células Cultivadas , AMP Cíclico/metabolismo , Dinoprostona/metabolismo , Ativação Enzimática , Músculo Liso Vascular/enzimologia , Músculo Liso Vascular/metabolismo , Ratos
5.
Diabetologia ; 58(4): 749-57, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25403481

RESUMO

AIMS/HYPOTHESIS: Nutrient homeostasis requires integration of signals generated by glucose metabolism and hormones. Expression of the calcium-stimulated adenylyl cyclase ADCY8 is regulated by glucose and the enzyme is capable of integrating signals from multiple pathways. It may thus have an important role in glucose-induced signalling and glucose homeostasis. METHODS: We used pharmacological and genetic approaches in beta cells to determine secretion and calcium metabolism. Furthermore, Adcy8 knockout mice were characterised. RESULTS: In clonal beta cells, inhibitors of adenylyl cyclases or their downstream targets reduced the glucose-induced increase in cytosolic calcium and insulin secretion. This was reproduced by knock-down of ADCY8, but not of ADCY1. These agents also inhibited glucose-induced increase in cytosolic calcium and electrical activity in primary beta cells and similar effects were observed after ADCY8 knock-down. Moreover, insulin secretion was diminished in islets from Adcy8 knockout mice. These mice were glucose intolerant after oral or intraperitoneal administration of glucose whereas their levels of glucagon-like peptide-1 remained unaltered. Finally, we knocked down ADCY8 in the ventromedial hypothalamus to evaluate the need for ADCY8 in the central regulation of glucose homeostasis. Whereas mice fed a standard diet had normal glucose levels, high-fat diet exacerbated glucose intolerance and knock-down mice were incapable of raising their plasma insulin levels. Finally we confirmed that ADCY8 is expressed in human islets. CONCLUSIONS/INTERPRETATIONS: Collectively, our findings demonstrate that ADCY8 is required for the physiological activation of glucose-induced signalling pathways in beta cells, for glucose tolerance and for hypothalamic adaptation to a high-fat diet via regulation of islet insulin secretion.


Assuntos
Adenilil Ciclases/metabolismo , Glicemia/metabolismo , Células Secretoras de Insulina/enzimologia , Adenilil Ciclases/deficiência , Adenilil Ciclases/genética , Animais , Cálcio/metabolismo , Linhagem Celular , Dieta Hiperlipídica , Modelos Animais de Doenças , Genótipo , Intolerância à Glucose/sangue , Intolerância à Glucose/enzimologia , Homeostase , Insulina/sangue , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Potenciais da Membrana , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Interferência de RNA , Transdução de Sinais , Fatores de Tempo , Transfecção , Núcleo Hipotalâmico Ventromedial/enzimologia
6.
Biochim Biophys Acta ; 1843(11): 2705-18, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25110346

RESUMO

UNLABELLED: The sarco(endo)plasmic reticulum Ca(2+)ATPases (SERCA) system, a key regulator of calcium cycling and signaling, is composed of several isoforms. We aimed to characterize the expression of SERCA isoforms in mouse cardiovascular tissues and their modulation in cardiovascular pathologies (heart failure and/or atherosclerosis). Five isoforms (SERCA2a, 2b, 3a, 3b and 3c) were detected in the mouse heart and thoracic aorta. Absolute mRNA quantification revealed SERCA2a as the dominant isoform in the heart (~99%). Both SERCA2 isoforms co-localized in cardiomyocytes (CM) longitudinal sarcoplasmic reticulum (SR), SERCA3b was located at the junctional SR. In the aorta, SERCA2a accounted for ~91% of total SERCA and SERCA2b for ~5%. Among SERCA3, SERCA3b was the most expressed (~3.3%), mainly found in vascular smooth muscle cells (VSMC), along with SERCA2a and 2b. In failing CM, SERCA2a was down-regulated by 2-fold and re-localized from longitudinal to junctional SR. A strong down-regulation of SERCA2a was also observed in atherosclerotic vessels containing mainly synthetic VSMCs. The proportion of both SERCA2b and SERCA3b increased to 9.5% and 8.3%, respectively. IN CONCLUSION: 1) SERCA2a is the major isoform in both cardiac and vascular myocytes; 2) the expression of SERCA2a mRNA is ~30 fold higher in the heart compared to vascular tissues; and 3) nearly half the amount of SERCA2a mRNA is measured in both failing cardiomyocytes and synthetic VSMCs compared to healthy tissues, with a relocation of SERCA2a in failing cardiomyocytes. Thus, SERCA2a is the principal regulator of excitation-contraction coupling in both CMs and contractile VSMCs.

7.
Biochim Biophys Acta Mol Cell Res ; 1871(2): 119645, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38016490

RESUMO

Adenylyl Cyclase 8E (AC8E), which lacks part of M1 transmembrane domain, has been previously shown to dimerize with AC3 and down-regulate its activity, but the molecular mechanism of this inhibitory effect has remained elusive. Here, we first show that AC8E also inhibits AC2 and AC6, highlighting the functional importance of this novel regulatory mechanism in the cAMP signaling pathway across AC families. We then completed the partial structure of Bos taurus AC9 using combinations of comparative modeling and fold recognition methods, and used this as a template to build the first full 3D-models of AC8 and AC8E. These models evidenced that the lack of M1 transmembrane domain of AC8E shifts the N-terminal domain, which impacts the orientation of the helical domains, thus affecting the catalytic site. This was confirmed in living cells with cAMP imaging, where we showed that the N-terminal domain is required for reducing cAMP production. Our data also show that AC8E prevents the translocation of other ACs towards the plasma membrane, further reducing the cAMP responsiveness to extracellular signals. This newly discovered dual inhibitory mechanism provides an additional level of regulation of cAMP-dependent signals integration.


Assuntos
Adenilil Ciclases , AMP Cíclico , Humanos , Animais , Bovinos , Adenilil Ciclases/química , AMP Cíclico/metabolismo , Transdução de Sinais , Domínio Catalítico , Membrana Celular/metabolismo
8.
J Biol Chem ; 287(30): 24978-89, 2012 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-22613711

RESUMO

Vascular smooth muscle cell (VSMC) trans-differentiation, or their switch from a contractile/quiescent to a secretory/inflammatory/migratory state, is known to play an important role in pathological vascular remodeling including atherosclerosis and postangioplasty restenosis. Several reports have established the Notch pathway as tightly regulating VSMC response to various stress factors through growth, migration, apoptosis, and de-differentiation. More recently, we showed that alterations of the Notch pathway also govern VSMC acquisition of the inflammatory state, one of the major events accelerating atherosclerosis. We also evidenced that the inflammatory context of atherosclerosis triggers a de novo expression of adenylyl cyclase isoform 8 (AC8), associated with the properties developed by trans-differentiated VSMCs. As an initial approach to understanding the regulation of AC8 expression, we examined the role of the Notch pathway. Here we show that inhibiting the Notch pathway enhances the effect of IL1ß on AC8 expression, amplifies its deleterious effects on the VSMC trans-differentiated phenotype, and decreases Notch target genes Hrt1 and Hrt3. Conversely, Notch activation resulted in blocking AC8 expression and up-regulated Hrt1 and Hrt3 expression. Furthermore, overexpressing Hrt1 and Hrt3 significantly decreased IL1ß-induced AC8 expression. In agreement with these in vitro findings, the in vivo rat carotid balloon-injury model of restenosis evidenced that AC8 de novo expression coincided with down-regulation of the Notch3 pathway. These results, demonstrating that the Notch pathway attenuates IL1ß-mediated AC8 up-regulation in trans-differentiated VSMCs, suggest that AC8 expression, besides being induced by the proinflammatory cytokine IL1ß, is also dependent on down-regulation of the Notch pathway occurring in an inflammatory context.


Assuntos
Adenilil Ciclases/biossíntese , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Interleucina-1beta/farmacologia , Músculo Liso Vascular/enzimologia , Miócitos de Músculo Liso/enzimologia , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Adenilil Ciclases/genética , Animais , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/metabolismo , Lesões das Artérias Carótidas/patologia , Transdiferenciação Celular , Modelos Animais de Doenças , Regulação Enzimológica da Expressão Gênica/genética , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1beta/metabolismo , Masculino , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Ratos , Ratos Wistar , Receptores Notch/genética , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , Transdução de Sinais/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
9.
J Mol Cell Cardiol ; 50(4): 621-33, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21195084

RESUMO

In blood vessels, tone is maintained by agonist-induced cytosolic Ca(2+) oscillations of quiescent/contractile vascular smooth muscle cells (VSMCs). However, in synthetic/proliferative VSMCs, Gq/phosphoinositide receptor-coupled agonists trigger a steady-state increase in cytosolic Ca(2+) followed by a Store Operated Calcium Entry (SOCE) which translates into activation of the proliferation-associated transcription factor NFAT. Here, we report that in human coronary artery smooth muscle cells (hCASMCs), the sarco/endoplasmic reticulum calcium ATPase type 2a (SERCA2a) expressed in the contractile form of the hCASMCs, controls the nature of the agonist-induced Ca(2+) transient and the resulting down-stream signaling pathway. Indeed, restoring SERCA2a expression by gene transfer in synthetic hCASMCs 1) increased Ca(2+) storage capacity; 2) modified agonist-induced IP(3)R Ca(2+) release from steady-state to oscillatory mode (the frequency of agonist-induced IP(3)R Ca(2+) signal was 11.66 ± 1.40/100 s in SERCA2a-expressing cells (n=39) vs 1.37 ± 0.20/100 s in control cells (n=45), p<0.01); 3) suppressed SOCE by preventing interactions between SR calcium sensor STIM1 and pore forming unit ORAI1; 4) inhibited calcium regulated transcription factor NFAT and its down-stream physiological function such as proliferation and migration. This study provides evidence for the first time that oscillatory and steady-state patterns of Ca(2+) transients have different effects on calcium-dependent physiological functions in smooth muscle cells.


Assuntos
Sinalização do Cálcio/fisiologia , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Fatores de Transcrição NFATC/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Western Blotting , Cálcio/metabolismo , Sinalização do Cálcio/genética , Movimento Celular/genética , Movimento Celular/fisiologia , Proliferação de Células , Células Cultivadas , Vasos Coronários/citologia , Ciclina D1/genética , Ciclina D1/metabolismo , Humanos , Imunoprecipitação , Microscopia Confocal , Modelos Biológicos , Fatores de Transcrição NFATC/genética , Reação em Cadeia da Polimerase , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
10.
J Pathol ; 221(3): 331-42, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20527026

RESUMO

Recently, we discovered on primary cell cultures that adenylyl cyclase type 8 (AC8) was involved in the transition of rat vascular smooth muscle cells (VSMCs) to an inflammatory phenotype. Here we demonstrate, in human vessels displaying early or advanced atherosclerotic lesions, that: (a) only intimal VSMCs strongly express AC8; and (b) very few AC8-positive VSMCs were detected in the medial layer, either in atherosclerotic or healthy arteries. Furthermore, over-expressing AC8 in primary rat VSMC cultures triggered the recolonization of a wounded zone and similar results were obtained in the presence of mitomycin, a potent inhibitor of proliferation. This phenomenon was prevented by silencing AC8. Indeed, in IL-1 beta-treated cells, AC8 silencing halted migration and decreased the matrix-metalloproteinases 2/9 secretion, known to be involved in VSMC migration. In vivo, we showed: (a) a pronounced up-regulation of AC8 expression in highly migrating VSMCs of the injured rat carotid artery; (b) an undetectable AC8 labelling in re-endothelized vessels where neo-intimal thickening had stopped. From our data, we conclude that AC8 expression appears closely linked to the properties developed by VSMCs in atherosclerosis and post-angioplasty neo-intima formation leading to restenosis. In addition, it reinforces the idea that VSMC responses to their cell environment greatly depend on the AC isoforms expressed and attributes a new role for AC8 in these pathological vascular processes.


Assuntos
Adenilil Ciclases/fisiologia , Aterosclerose/enzimologia , Músculo Liso Vascular/enzimologia , Miócitos de Músculo Liso/enzimologia , Adenilil Ciclases/genética , Adenilil Ciclases/metabolismo , Animais , Aterosclerose/patologia , Lesões das Artérias Carótidas/enzimologia , Movimento Celular/fisiologia , Proliferação de Células , Células Cultivadas , Humanos , Interleucina-1beta/farmacologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Pessoa de Meia-Idade , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , RNA Interferente Pequeno/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
11.
J Am Heart Assoc ; 9(2): e014276, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31959031

RESUMO

Background Heart attacks and stroke often result from occlusive thrombi following the rupture of vulnerable atherosclerotic plaques. Vascular smooth muscle cells (VSMCs) play a pivotal role in plaque vulnerability because of their switch towards a proinflammatory/macrophage-like phenotype when in the context of atherosclerosis. The prometastatic transcription factor Slug/Snail2 is a critical regulator of cell phenotypic transition. Here, we aimed to investigate the role of Slug in the transdifferentiation process of VSMCs occurring during atherogenesis. Methods and Results In rat and human primary aortic smooth muscle cells, Slug protein expression is strongly and rapidly increased by platelet-derived growth factor-BB (PDGF-BB). PDGF-BB increases Slug protein without affecting mRNA levels indicating that this growth factor stabilizes Slug protein. Immunocytochemistry and subcellular fractionation experiments reveal that PDGF-BB triggers a rapid accumulation of Slug in VSMC nuclei. Using pharmacological tools, we show that the PDGF-BB-dependent mechanism of Slug stabilization in VSMCs involves the extracellular signal-regulated kinase 1/2 pathway. Immunohistochemistry experiments on type V and type VI atherosclerotic lesions of human carotids show smooth muscle-specific myosin heavy chain-/Slug-positive cells surrounding the prothrombotic lipid core. In VSMCs, Slug siRNAs inhibit prostaglandin E2 secretion and prevent the inhibition of cholesterol efflux gene expression mediated by PDGF-BB, known to be involved in plaque vulnerability and/or thrombogenicity. Conclusions Our results highlight, for the first time, a role of Slug in aortic smooth muscle cell transdifferentiation and enable us to consider Slug as an actor playing a role in the atherosclerotic plaque progression towards a life-threatening phenotype. This also argues for common features between acute cardiovascular events and cancer.


Assuntos
Aterosclerose/metabolismo , Becaplermina/farmacologia , Transdiferenciação Celular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Fatores de Transcrição da Família Snail/metabolismo , Animais , Aterosclerose/genética , Aterosclerose/patologia , Células Cultivadas , Dinoprostona/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Cadeias Pesadas de Miosina/metabolismo , Ratos , Transdução de Sinais , Fatores de Transcrição da Família Snail/genética
12.
Am J Pathol ; 172(5): 1430-40, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18403593

RESUMO

The Notch pathway is involved in the regulation of the migratory/proliferative phenotype acquired by vascular smooth muscle cells (VSMCs) in the pro-inflammatory context of vascular diseases. Here, we investigated whether docosahexaenoic acid (DHA), a polyunsaturated, omega-3 fatty acid, could reduce fibrinolytic/matrix-metalloproteinase (MMP) activity and whether this reduction occurs through the modulation of Notch signaling. Rat VSMCs were transdifferentiated with interleukin-1beta and then treated with DHA. Migration/proliferation was determined by performing a wound healing assay and measuring MMP-2/-9 activity, type 1 plasminogen activator inhibitor levels, and the expression of these proteins. The involvement of Notch in regulating the fibrinolytic/MMP system was evidenced using Notch pathway inhibitors and the forced expression of Notch1 and Notch3 intracellular domains. DHA significantly decreased VSMC migration/proliferation induced by interleukin-1beta as well as fibrinolytic/MMP activity. Prevention of Notch1 target gene transcription enhanced the interleukin-1beta effects on MMPs and on migration, whereas Notch3 intracellular domain overexpression reduced these effects. Finally, DHA increased Notch3 expression, Hes-1 transcription (a Notch target gene), and enhanced gamma-secretase complex activity. These results suggest that inhibition of the Notch pathway participates in the transition of VSMCs toward a migratory phenotype. These results also suggest that the beneficial inhibitory effects of DHA on fibrinolytic/MMP activity are related in part to the effects of DHA on the expression of Notch pathway components, providing new insight into the mechanisms by which omega-3 fatty acids prevent cardiovascular diseases.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/fisiologia , Receptores Notch/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Movimento Celular , Células Cultivadas , Ativação Enzimática , Proteínas de Homeodomínio/metabolismo , Masculino , Miócitos de Músculo Liso/efeitos dos fármacos , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , Fatores de Transcrição HES-1
13.
Cardiovasc Res ; 115(12): 1778-1790, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30605506

RESUMO

AIMS: Increase of cardiac cAMP bioavailability and PKA activity through adenylyl-cyclase 8 (AC8) overexpression enhances contractile function in young transgenic mice (AC8TG). Ageing is associated with decline of cardiac contraction partly by the desensitization of ß-adrenergic/cAMP signalling. Our objective was to evaluate cardiac cAMP signalling as age increases between 2 months and 12 months and to explore whether increasing the bioavailability of cAMP by overexpression of AC8 could prevent cardiac dysfunction related to age. METHODS AND RESULTS: Cardiac cAMP pathway and contractile function were evaluated in AC8TG and their non-transgenic littermates (NTG) at 2- and 12 months old. AC8TG demonstrated increased AC8, PDE1, 3B and 4D expression at both ages, resulting in increased phosphodiesterase and PKA activity, and increased phosphorylation of several PKA targets including sarco(endo)plasmic-reticulum-calcium-ATPase (SERCA2a) cofactor phospholamban (PLN) and GSK3α/ß a main regulator of hypertrophic growth and ageing. Confocal immunofluorescence revealed that the major phospho-PKA substrates were co-localized with Z-line in 2-month-old NTG but with Z-line interspace in AC8TG, confirming the increase of PKA activity in the compartment of PLN/SERCA2a. In both 12-month-old NTG and AC8TG, PLN and GSK3α/ß phosphorylation was increased together with main localization of phospho-PKA substrates in Z-line interspaces. Haemodynamics demonstrated an increased contractile function in 2- and 12-month-old AC8TG, but not in NTG. In contrast, echocardiography and tissue Doppler imaging (TDI) performed in conscious mice unmasked myocardial dysfunction with a decrease of systolic strain rate in both old AC8TG and NTG. In AC8TG TDI showed a reduced strain rate even in 2-month-old animals. Development of age-related cardiac dysfunction was accelerated in AC8TG, leading to heart failure (HF) and premature death. Histological analysis confirmed early cardiomyocyte hypertrophy and interstitial fibrosis in AC8TG when compared with NTG. CONCLUSION: Our data demonstrated an early and accelerated cardiac remodelling in AC8TG mice, leading to the development of HF and reduced lifespan. Age-related reorganization of cAMP/PKA signalling can accelerate cardiac ageing, partly through GSK3α/ß phosphorylation.


Assuntos
Adenilil Ciclases/metabolismo , AMP Cíclico/metabolismo , Insuficiência Cardíaca/enzimologia , Hemodinâmica , Contração Miocárdica , Miocárdio/enzimologia , Disfunção Ventricular Esquerda/enzimologia , Função Ventricular Esquerda , Adenilil Ciclases/genética , Fatores Etários , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Progressão da Doença , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Sistemas do Segundo Mensageiro , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/genética , Disfunção Ventricular Esquerda/fisiopatologia
15.
Geroscience ; 39(5-6): 499-550, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29270905

RESUMO

A paradox is a seemingly absurd or impossible concept, proposition, or theory that is often difficult to understand or explain, sometimes apparently self-contradictory, and yet ultimately correct or true. How is it possible, for example, that oxygen "a toxic environmental poison" could be also indispensable for life (Beckman and Ames Physiol Rev 78(2):547-81, 1998; Stadtman and Berlett Chem Res Toxicol 10(5):485-94, 1997)?: the so-called Oxygen Paradox (Davies and Ursini 1995; Davies Biochem Soc Symp 61:1-31, 1995). How can French people apparently disregard the rule that high dietary intakes of cholesterol and saturated fats (e.g., cheese and paté) will result in an early death from cardiovascular diseases (Renaud and de Lorgeril Lancet 339(8808):1523-6, 1992; Catalgol et al. Front Pharmacol 3:141, 2012; Eisenberg et al. Nat Med 22(12):1428-1438, 2016)?: the so-called, French Paradox. Doubtless, the truth is not a duality and epistemological bias probably generates apparently self-contradictory conclusions. Perhaps nowhere in biology are there so many apparently contradictory views, and even experimental results, affecting human physiology and pathology as in the fields of free radicals and oxidative stress, antioxidants, foods and drinks, and dietary recommendations; this is particularly true when issues such as disease-susceptibility or avoidance, "healthspan," "lifespan," and ageing are involved. Consider, for example, the apparently paradoxical observation that treatment with low doses of a substance that is toxic at high concentrations may actually induce transient adaptations that protect against a subsequent exposure to the same (or similar) toxin. This particular paradox is now mechanistically explained as "Adaptive Homeostasis" (Davies Mol Asp Med 49:1-7, 2016; Pomatto et al. 2017a; Lomeli et al. Clin Sci (Lond) 131(21):2573-2599, 2017; Pomatto and Davies 2017); the non-damaging process by which an apparent toxicant can activate biological signal transduction pathways to increase expression of protective genes, by mechanisms that are completely different from those by which the same agent induces toxicity at high concentrations. In this review, we explore the influences and effects of paradoxes such as the Oxygen Paradox and the French Paradox on the etiology, progression, and outcomes of many of the major human age-related diseases, as well as the basic biological phenomenon of ageing itself.


Assuntos
Adaptação Fisiológica , Envelhecimento/genética , Dieta Rica em Proteínas/estatística & dados numéricos , Hipercolesterolemia/epidemiologia , Estresse Oxidativo/fisiologia , Oxigênio/metabolismo , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Feminino , França , Radicais Livres/metabolismo , Avaliação Geriátrica , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco
16.
J Vis Exp ; (116)2016 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-27805576

RESUMO

The cerebral arterial circle (circulus arteriosus cerebri) or circle of Willis (CoW) is a circulatory anastomosis surrounding the optic chiasma and hypothalamus that supplies blood to the brain and surrounding structures. It has been implicated in several cerebrovascular disorders, including cerebral amyloid angiopathy (CAA)-associated vasculopathies, intracranial atherosclerosis and intracranial aneurysms. Studies of the molecular mechanisms underlying these diseases for the identification of novel drug targets for their prevention require animal models. Some of these models may be transgenic, whereas others will involve isolation of the cerebro-vasculature, including the CoW.The method described here is suitable for CoW isolation in any mouse lineage and has considerable potential for screening (expression of genes, protein production, posttranslational protein modifications, secretome analysis, etc.) studies on the large vessels of the mouse cerebro-vasculature. It can also be used for ex vivo studies, by adapting the organ bath system developed for isolated mouse olfactory arteries.


Assuntos
Círculo Arterial do Cérebro , Aneurisma Intracraniano , Animais , Animais Geneticamente Modificados , Encéfalo , Circulação Cerebrovascular , Camundongos , Técnicas de Cultura de Tecidos
17.
Biol Aujourdhui ; 210(3): 153-166, 2016.
Artigo em Francês | MEDLINE | ID: mdl-27813476

RESUMO

In response to various types of vascular stress, the smooth muscle cells of the vessel wall (VSMCs) change phenotype and acquire the capacity to react to abnormal signals. This phenomenon favors the involvement of these cells in the development of major vascular diseases, such as atherosclerosis, and some complications of angioplasty, such as restenosis. The cyclic adenosine monophosphate (cAMP) pathway plays a key role in the integration of stimuli from the immediate environment and in the development of cellular responses. The temporal and spatial subcellular compartmentalization of cAMP ensures that the signals transmitted are specific. This compartmentalization is dependent on the diversity of (1) proteins directly or indirectly regulating the synthesis, degradation or release of cAMP; (2) intracellular effectors of cAMP; (3) isoforms of all these proteins with unique biochemical properties and unique patterns of regulation and (4) the scaffolding proteins on which the macromolecular complexes are built. This review illustrates the ways in which changes in the profile of adenylyl cyclases (ACs) may play critical roles in signal integration, the response of muscle cells and pathological vascular remodeling. It also illustrates the relevance of the renewed consideration of ACs as potentially interesting treatment targets.


Assuntos
Adenilil Ciclases/fisiologia , Transdiferenciação Celular , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/fisiologia , Remodelação Vascular/fisiologia , Animais , AMP Cíclico/metabolismo , AMP Cíclico/fisiologia , Humanos , Terapia de Alvo Molecular/tendências , Transdução de Sinais
18.
Oncotarget ; 6(41): 43216-29, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26646450

RESUMO

The Notch1 and Notch4 signaling pathways regulate endothelial cell homeostasis. Inflammatory cytokines induce the expression of endothelial adhesion molecules, including VCAM1, partly by downregulating Notch4 signaling. We investigated the role of endothelial Notch1 in this IL-1ß-mediated process. Brief treatment with IL-1ß upregulated endothelial VCAM1 and Notch ligand Jagged1. IL-1ß decreased Notch1 mRNA levels, but levels of the active Notch1ICD protein remained constant. IL-1ß-mediated VCAM1 induction was downregulated in endothelial cells subjected to pretreatment with a pharmacological inhibitor of the γ-secretase, which activates Notch receptors, producing NotchICD. It was also downregulated in cells in which Notch1 and/or Jagged1 were silenced.Conversely, the forced expression of Notch1ICD in naïve endothelial cells upregulated VCAM1 per se and amplified IL-1ß-mediated VCAM1 induction. Jagged1 levels increased and Notch4 signaling was downregulated in parallel. Finally, Notch1ICD and Jagged1 expression was upregulated in the endothelium of the liver in a model of chronic liver inflammation.In conclusion, we describe here a cell-autonomous, pro-inflammatory endothelial Notch1-Jagged1 circuit (i) triggering the expression of VCAM1 even in the absence of inflammatory cytokines and (ii) enhancing the effects of IL-1ß. Thus, IL-1ß regulates Notch1 and Notch4 activity in opposite directions, consistent with a selective targeting of Notch1 in inflamed endothelium.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Células Endoteliais/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Interleucina-1beta/metabolismo , Proteínas de Membrana/metabolismo , Receptor Notch1/metabolismo , Transdução de Sinais/fisiologia , Molécula 1 de Adesão de Célula Vascular/biossíntese , Animais , Western Blotting , Linhagem Celular , Separação Celular , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imunofluorescência , Regulação da Expressão Gênica/fisiologia , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Inflamação/metabolismo , Proteína Jagged-1 , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , RNA Interferente Pequeno , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Serrate-Jagged , Transfecção
19.
Aging Cell ; 12(3): 358-69, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23425004

RESUMO

Several studies have shown that the accumulation of ß-amyloid peptides in the brain parenchyma or vessel wall generates an inflammatory environment. Some even suggest that there is a cause-and-effect relationship between inflammation and the development of Alzheimer's disease and/or cerebral amyloid angiopathy (CAA). Here, we studied the ability of wild-type Aß1-40 -peptide (the main amyloid peptide that accumulates in the vessel wall in sporadic forms of CAA) to modulate the phenotypic transition of vascular smooth muscle cells (VSMCs) toward an inflammatory/de-differentiated state. We found that Aß1-40 -peptide alone neither induces an inflammatory response, nor decreases the expression of contractile markers; however, the inflammatory response of VSMCs exposed to Aß1-40 -peptide prior to the addition of the pro-inflammatory cytokine IL-1ß is greatly intensified compared with IL-1ß-treated VSMCs previously un-exposed to Aß1-40 -peptide. Similar conclusions could be drawn when tracking the decline of contractile markers. Furthermore, we found that the mechanism of this potentiation highly depends on an Aß1-40 preactivation of the PI3 Kinase and possibly NFκB pathway; indeed, blocking the activation of these pathways during Aß1-40 -peptide treatment completely suppressed the observed potentiation. Finally, strengthening the possible in vivo relevance of our findings, we evidenced that endothelial cells exposed to Aß1-40 -peptide generate an inflammatory context and have similar effects than the ones described with IL-1ß. These results reinforce the idea that intraparietal amyloid deposits triggering adhesion molecules in endothelial cells, contribute to the transition of VSMCs to an inflammatory/de-differentiated phenotype. Therefore, we suggest that acute inflammatory episodes may increase vascular alterations and contribute to the ontogenesis of CAA.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Encéfalo/irrigação sanguínea , Desdiferenciação Celular , Inflamação/imunologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/imunologia , Fragmentos de Peptídeos/metabolismo , Doença de Alzheimer , Animais , Células Cultivadas , Angiopatia Amiloide Cerebral/imunologia , Meios de Cultivo Condicionados , Ativação Enzimática , Interleucina-1beta/farmacologia , Camundongos , Músculo Liso Vascular/metabolismo , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo
20.
Aging Cell ; 11(3): 384-93, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22260497

RESUMO

Cerebral amyloid angiopathy (CAA) is an important cause of intracerebral hemorrhages in the elderly, characterized by amyloid-ß (Aß) peptide accumulating in central nervous system blood vessels. Within the vessel walls, Aß-peptide deposits [composed mainly of wild-type (WT) Aß(1-40) peptide in sporadic forms] induce impaired adhesion of vascular smooth muscle cells (VSMCs) to the extracellular matrix (ECM) associated with their degeneration. This process often results in a loss of blood vessel wall integrity and ultimately translates into cerebral ischemia and microhemorrhages, both clinical features of CAA. In this study, we decipher the molecular mechanism of matrix metalloprotease (MMP)-2 activation in WT-Aß(1-40) -treated VSMC and provide evidence that MMP activity, although playing a critical role in cell detachment disrupting ECM components, is not involved in the WT-Aß(1-40) -induced degeneration of VSMCs. Indeed, whereas this peptide clearly induced VSMC apoptosis, neither preventing MMP-2 activity nor hampering the expression of membrane type1-MMP, or preventing tissue inhibitors of MMPs-2 (TIMP-2) recruitment (two proteins evidenced here as involved in MMP-2 activation), reduced the number of dead cells. Even the use of broad-range MMP inhibitors (GM6001 and Batimastat) did not affect WT-Aß(1-40) -induced cell apoptosis. Our results, in contrast to those obtained using the Aß(1-40) Dutch variant suggesting a link between MMP-2 activity, VSMC mortality and degradation of specific matrix components, indicate that the ontogenesis of the Dutch familial and sporadic forms of CAAs is different. ECM degradation and VSMC degeneration would be tightly connected in the Dutch familial form while being two independent processes in sporadic forms of CAA.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Angiopatia Amiloide Cerebral/metabolismo , Metaloproteinases da Matriz/metabolismo , Músculo Liso Vascular/citologia , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Animais , Apoptose/fisiologia , Morte Celular/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Angiopatia Amiloide Cerebral/enzimologia , Angiopatia Amiloide Cerebral/patologia , Humanos , Masculino , Dados de Sequência Molecular , Músculo Liso Vascular/enzimologia , Músculo Liso Vascular/metabolismo , Ratos , Ratos Wistar , Transfecção
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