RESUMO
Heart and kidney have a closely interrelated pathophysiology. Acute kidney injury (AKI) is associated with significantly increased rates of cardiovascular events, a relationship defined as cardiorenal syndrome type 3 (CRS3). The underlying mechanisms that trigger heart disease remain, however, unknown, particularly concerning the clinical impact of AKI on cardiac outcomes and overall mortality. Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) are independently involved in the pathogenesis of both heart and kidney failure, and recent studies have proposed TWEAK as a possible therapeutic target; however, its specific role in cardiac damage associated with CRS3 remains to be clarified. Firstly, we demonstrated in a retrospective longitudinal clinical study that soluble TWEAK plasma levels were a predictive biomarker of mortality in patients with AKI. Furthermore, the exogenous application of TWEAK to native ventricular cardiomyocytes induced relevant calcium (Ca2+ ) handling alterations. Next, we investigated the role of the TWEAK-Fn14 axis in cardiomyocyte function following renal ischaemia-reperfusion (I/R) injury in mice. We observed that TWEAK-Fn14 signalling was activated in the hearts of AKI mice. Mice also showed significantly altered intra-cardiomyocyte Ca2+ handling and arrhythmogenic Ca2+ events through an impairment in sarcoplasmic reticulum Ca2+ -adenosine triphosphatase 2a pump (SERCA2a ) and ryanodine receptor (RyR2 ) function. Administration of anti-TWEAK antibody after reperfusion significantly improved alterations in Ca2+ cycling and arrhythmogenic events and prevented SERCA2a and RyR2 modifications. In conclusion, this study establishes the relevance of the TWEAK-Fn14 pathway in cardiac dysfunction linked to CRS3, both as a predictor of mortality in patients with AKI and as a Ca2+ mishandling inducer in cardiomyocytes, and highlights the cardioprotective benefits of TWEAK targeting in CRS3. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
Assuntos
Injúria Renal Aguda , Cálcio , Humanos , Camundongos , Animais , Cálcio/metabolismo , Receptor de TWEAK/metabolismo , Estudos Retrospectivos , Citocina TWEAK/metabolismo , Fatores de Necrose Tumoral/metabolismo , Miócitos Cardíacos/metabolismo , Injúria Renal Aguda/metabolismoRESUMO
Acute kidney injury (AKI) is associated with an elevated risk of cardiovascular major events and mortality. The pathophysiological mechanisms underlying the complex cardiorenal network interaction remain unresolved. It is known that the presence of AKI and its evolution are significantly associated with an alteration in the anti-aging factor klotho expression. However, it is unknown whether a klotho deficiency might aggravate cardiac damage after AKI. We examined intracellular calcium (Ca2+) handling in native ventricular isolated cardiomyocytes from wild-type (+/+) and heterozygous hypomorphic mice for the klotho gene (+/kl) in which an overdose of folic acid was administered to induce AKI. Twenty-four hours after AKI induction, cardiomyocyte contraction was decreased in mice with the partial deletion of klotho expression (heterozygous hypomorphic klotho named +/kl). This was accompanied by alterations in Ca2+ transients during systole and an impairment of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) function in +/kl mice after AKI induction. Moreover, Ca2+ spark frequency and the incidence of Ca2+ pro-arrhythmic events were greater in cardiomyocytes from heterozygous hypomorphic klotho compared to wild-type mice after AKI. A decrease in klotho expression plays a role in cardiorenal damage aggravating cardiac Ca2+ mishandling after an AKI, providing the basis for future targeted approaches directed to control klotho expression as novel therapeutic strategies to reduce the cardiac burden that affects AKI patients.
Assuntos
Injúria Renal Aguda , Glucuronidase , Camundongos , Animais , Glucuronidase/genética , Glucuronidase/metabolismo , Cálcio/metabolismo , Injúria Renal Aguda/etiologia , Miócitos Cardíacos/metabolismo , Cálcio da DietaRESUMO
BACKGROUND: Chronic kidney disease (CKD) is associated with increased propensity for arrhythmias. In this context, ventricular repolarization alterations have been shown to predispose to fatal arrhythmias and sudden cardiac death. Between mineral bone disturbances in CKD patients, increased fibroblast growth factor (FGF) 23 and decreased Klotho are emerging as important effectors of cardiovascular disease. However, the relationship between imbalanced FGF23-Klotho axis and the development of cardiac arrhythmias in CKD remains unknown. METHODS: We carried out a translational approach to study the relationship between the FGF23-Klotho signaling axis and acquired long QT syndrome in CKD-associated uremia. FGF23 levels and cardiac repolarization dynamics were analyzed in patients with dialysis-dependent CKD and in uremic mouse models of 5/6 nephrectomy (Nfx) and Klotho deficiency (hypomorphism), which show very high systemic FGF23 levels. RESULTS: Patients in the top quartile of FGF23 levels had a higher occurrence of very long QT intervals (> 490 ms) than peers in the lowest quartile. Experimentally, FGF23 induced QT prolongation in healthy mice. Similarly, alterations in cardiac repolarization and QT prolongation were observed in Nfx mice and in Klotho hypomorphic mice. QT prolongation in Nfx mice was explained by a significant decrease in the fast transient outward potassium (K+) current (Itof), caused by the downregulation of K+ channel 4.2 subunit (Kv4.2) expression. Kv4.2 expression was also significantly reduced in ventricular cardiomyocytes exposed to FGF23. Enhancing Klotho availability prevented both long QT prolongation and reduced Itof current. Likewise, administration of recombinant Klotho blocked the downregulation of Kv4.2 expression in Nfx mice and in FGF23-exposed cardiomyocytes. CONCLUSION: The FGF23-Klotho axis emerges as a new therapeutic target to prevent acquired long QT syndrome in uremia by minimizing the predisposition to potentially fatal ventricular arrhythmias and sudden cardiac death in patients with CKD.
Assuntos
Síndrome do QT Longo , Insuficiência Renal Crônica , Uremia , Envelhecimento , Animais , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/genética , Glucuronidase/genética , Humanos , Proteínas Klotho , Camundongos , Insuficiência Renal Crônica/complicações , Uremia/complicaçõesRESUMO
BACKGROUND: Acute renal failure (ARF) following renal ischemia-reperfusion (I/R) injury is considered a relevant risk factor for cardiac damage, but the underlying mechanisms, particularly those triggered at cardiomyocyte level, are unknown. METHODS: We examined intracellular Ca2+ dynamics in adult ventricular cardiomyocytes isolated from C57BL/6 mice 7 or 15 days following unilateral renal I/R. RESULTS: After 7 days of I/R, the cell contraction was significantly lower in cardiomyocytes compared to sham-treated mice. It was accompanied by a significant decrease in both systolic Ca2+ transients and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) activity measured as Ca2+ transients decay. Moreover, the incidence of pro-arrhythmic events, measured as the number of Ca2+ sparks, waves or automatic Ca2+ transients, was greater in cardiomyocytes from mice 7 days after I/R than from sham-treated mice. Ca2+ mishandling related to systolic Ca2+ transients and contraction were recovered to sham values 15 days after I/R, but Ca2+ sparks frequency and arrhythmic events remained elevated. CONCLUSIONS: Renal I/R injury causes a cardiomyocyte Ca2+ cycle dysfunction at medium (contraction-relaxation dysfunction) and long term (Ca2+ leak), after 7 and 15 days of renal reperfusion, respectively.
Assuntos
Injúria Renal Aguda/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Isquemia/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Animais , Cálcio da Dieta/metabolismo , Retículo Endoplasmático/metabolismo , Ventrículos do Coração/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Contração Miocárdica/fisiologia , Miócitos Cardíacos/metabolismo , Reperfusão/métodos , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo SarcoplasmáticoRESUMO
N-Propargylamines are useful synthetic scaffolds for the synthesis of bioactive molecules, and in addition, they possess important pharmacological activities. We obtained several neuroprotective molecules, chiral 1,2-amino alcohols and 1,2-diamines, able to reduce by almost 70% the rotenone and oligomycin A-induced damage in SH-SY5Y cells. Furthermore, some molecules assessed also counteracted the toxicity evoked by the Ser/Thr phosphatase inhibitor okadaic acid. Before extrapolating these data to preclinical studies, we analyze the molecules through an in silico prediction system to detect carcinogenicity risk or other toxic effects. In light of these promising results, these molecules may be considered as a lead family of neuroprotective and relatively safe compounds.
Assuntos
Amino Álcoois/farmacologia , Morfinanos/farmacologia , Fármacos Neuroprotetores/farmacologia , Amino Álcoois/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Estrutura Molecular , Morfinanos/química , Fármacos Neuroprotetores/químicaRESUMO
Risk of cardiovascular disease (CVD) increases considerably as renal function declines in chronic kidney disease (CKD). Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) has emerged as a novel innate immune receptor involved in both CVD and CKD. Following activation, NOD1 undergoes a conformational change that allows the activation of the receptor-interacting serine/threonine protein kinase 2 (RIP2), promoting an inflammatory response. We evaluated whether the genetic deficiency of Nod1 or Rip2 in mice could prevent cardiac Ca2+ mishandling induced by sixth nephrectomy (Nx), a model of CKD. We examined intracellular Ca2+ dynamics in cardiomyocytes from Wild-type (Wt), Nod1-/- and Rip2-/- sham-operated or nephrectomized mice. Compared with Wt cardiomyocytes, Wt-Nx cells showed an impairment in the properties and kinetics of the intracellular Ca2+ transients, a reduction in both cell shortening and sarcoplasmic reticulum Ca2+ load, together with an increase in diastolic Ca2+ leak. Cardiomyocytes from Nod1-/--Nx and Rip2-/--Nx mice showed a significant amelioration in Ca2+ mishandling without modifying the kidney impairment induced by Nx. In conclusion, Nod1 and Rip2 deficiency prevents the intracellular Ca2+ mishandling induced by experimental CKD, unveiling new innate immune targets for the development of innovative therapeutic strategies to reduce cardiac complications in patients with CKD.
Assuntos
Rim/metabolismo , Proteína Adaptadora de Sinalização NOD1/genética , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Insuficiência Renal Crônica/genética , Animais , Cálcio/metabolismo , Sinalização do Cálcio/genética , Modelos Animais de Doenças , Humanos , Rim/patologia , Camundongos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , NF-kappa B/genética , Proteína Adaptadora de Sinalização NOD1/ultraestrutura , Conformação Proteica , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/ultraestrutura , Insuficiência Renal Crônica/patologia , Retículo Sarcoplasmático/genética , Retículo Sarcoplasmático/patologiaRESUMO
An improved understanding of pathogenic pathways in AKI may identify novel therapeutic approaches. Previously, we conducted unbiased liquid chromatography-tandem mass spectrometry-based protein expression profiling of the renal proteome in mice with acute folate nephropathy. Here, analysis of the dataset identified enrichment of pathways involving NFκB in the kidney cortex, and a targeted data mining approach identified components of the noncanonical NFκB pathway, including the upstream kinase mitogen-activated protein kinase kinase kinase 14 (MAP3K14), the NFκB DNA binding heterodimer RelB/NFκB2, and proteins involved in NFκB2 p100 ubiquitination and proteasomal processing to p52, as upregulated. Immunohistochemistry localized MAP3K14 expression to tubular cells in acute folate nephropathy and human AKI. In vivo, kidney expression levels of NFκB2 p100 and p52 increased rapidly after folic acid injection, as did DNA binding of RelB and NFκB2, detected in nuclei isolated from the kidneys. Compared with wild-type mice, MAP3K14 activity-deficient aly/aly (MAP3K14aly/aly) mice had less kidney dysfunction, inflammation, and apoptosis in acute folate nephropathy and less kidney dysfunction and a lower mortality rate in cisplatin-induced AKI. The exchange of bone marrow between wild-type and MAP3K14aly/aly mice did not affect the survival rate of either group after folic acid injection. In cultured tubular cells, MAP3K14 small interfering RNA targeting decreased inflammation and cell death. Additionally, cell culture and in vivo studies identified the chemokines MCP-1, RANTES, and CXCL10 as MAP3K14 targets in tubular cells. In conclusion, MAP3K14 promotes kidney injury through promotion of inflammation and cell death and is a promising novel therapeutic target.
Assuntos
Injúria Renal Aguda/enzimologia , Injúria Renal Aguda/etiologia , Proteína Quinase 14 Ativada por Mitógeno/fisiologia , Animais , Feminino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: Renal ischemia and reperfusion injury (IRI) is the main cause of acute kidney injury (AKI). AKI induces the development of cardiac hypertrophy (CH) during cardiorenal syndrome (CRS), and cardiomyocyte calcium mishandling though systemic inflammation after 8 days of renal IRI. Klotho has recently been described as an anti-inflammatory component. Given this, Klotho treatment could prevent or attenuate the inflammation, thereby also preventing electrical cardiac outcomes incurred by CRS. The aim of this study was to investigate the therapeutic role of Klotho in CRS after unilateral renal IRI through its anti-inflammatory action. METHODS: We examined renal tissue structure and function, intracellular Ca2+ dynamics in adult ventricular cardiomyocytes and serum cytokine levels from C57BL/6 mice that suffered unilateral renal IRI by occluding the left pedicle for 60 min and reperfusion for 8 days. The animals were treated with recombinant Klotho protein starting from the day of the surgery, then daily for 8 days. RESULTS: After Klotho treatment for 8 days, the left renal tissue remained damaged, however the renal function was restored due to the right kidney tissue preservation. In parallel, Klotho also prevented an increase in serum interleukin (IL-) 6, IL-1ß, and tumor necrosis factor alpha (TNF-α) levels. CH and low cell contraction were also prevented, as well as a decrease in systolic Ca2+ transients and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) activity measured as Ca2+ transient decay, an increase in spontaneous Ca2+ release and the incidence of pro-arrhythmic events. CONCLUSIONS: The Klotho treatment showed promise, playing an important role in the pathophysiology of CRS. We were unable to observe a total renoprotective role of the compound in the model; in turn, a cardioprotective role of Klotho was demonstrated through the prevention of hypertrophy and normalization of the Ca2+ cycle dysfunction of cardiomyocytes. We propose that Klotho acts in the cardiorenal syndrome by systematically preventing inflammation and increased FGF23, alleviating cardiac outcomes.
Assuntos
Injúria Renal Aguda , Síndrome Cardiorrenal , Traumatismo por Reperfusão , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/prevenção & controle , Animais , Síndrome Cardiorrenal/tratamento farmacológico , Síndrome Cardiorrenal/prevenção & controle , Inflamação/metabolismo , Isquemia/metabolismo , Rim , Camundongos , Camundongos Endogâmicos C57BL , Reperfusão , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/prevenção & controleRESUMO
AIMS: The aim of this study was to determine whether arterial stiffness assessed with the biochemical parameter active matrix metalloproteinase (MMP)-9 and the clinical parameters pulse pressure (PP) and pulse wave velocity predicts the response to spironolactone in resistant hypertension (RH). METHODS AND RESULTS: Ambulatory blood pressure (BP) and active MMP-9 (measured by zymography and ELISA) were measured at baseline, and patients were classified as having pseudo-RH or RH. Patients with RH received spironolactone and the response was determined after 8 weeks by ambulatory BP monitoring: those who achieved BP goals were considered controlled (CRH) and those who did not were considered uncontrolled (UCRH). Plasma active MMP-9 was significantly higher in patients with RH than with pseudo-RH, and correlated with 24 h systolic BP and PP. Receiver operating characteristic analysis indicated that active MMP-9 could predict the response to spironolactone, and its combination with 24 h PP and pulse wave velocity significantly improved this prediction. Moreover, plasma of patients with UCRH induced the MMP-9 expression pathway. CONCLUSION: We propose active MMP-9 as a useful biomarker to identify patients with RH who will not respond to spironolactone. Combining MMP-9 activity with classical arterial stiffness parameters improves the prediction of the clinical response to spironolactone and might contribute to guide the most appropriate therapeutic decisions for patients with RH.
Assuntos
Hipertensão , Rigidez Vascular , Monitorização Ambulatorial da Pressão Arterial , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Metaloproteinase 9 da Matriz/uso terapêutico , Análise de Onda de Pulso , Espironolactona/efeitos adversosRESUMO
Biomarkers of mineral bone disorders (MBD) including phosphorus, fibroblast growth factor (FGF)-23 and Klotho are strongly altered in patients with acute kidney injury (AKI) who have high cardiac outcomes and mortality rates. However, the crosslink between MBD and cardiac damage after an AKI episode still remains unclear. We tested MBD and cardiac biomarkers in an experimental AKI model after 24 or 72 hours of folic acid injection and we analyzed structural cardiac remodeling, intracellular calcium (Ca2+) dynamics in cardiomyocytes and cardiac rhythm. AKI mice presented high levels of FGF-23, phosphorus and cardiac troponin T and exhibited a cardiac hypertrophy phenotype accompanied by an increase in systolic Ca2+ release 24 hours after AKI. Ca2+ transients and contractile dysfunction were reduced 72 hours after AKI while diastolic sarcoplasmic reticulum Ca2+ leak, pro-arrhythmogenic Ca2+ events and ventricular arrhythmias were increased. These cardiac events were linked to the activation of the calcium/calmodulin-dependent kinase II pathway through the increased phosphorylation of ryanodine receptors and phospholamban specific sites after AKI. Cardiac hypertrophy and the altered intracellular Ca2+ dynamics were prevented in transgenic mice overexpressing Klotho after AKI induction. In a translational retrospective longitudinal clinical study, we determined that combining FGF-23 and phosphorus with cardiac troponin T levels achieved a better prediction of mortality in AKI patients at hospital admission. Thus, monitoring MBD and cardiac damage biomarkers could be crucial to prevent mortality in AKI patients. In this setting, Klotho might be considered as a new cardioprotective therapeutic tool to prevent deleterious cardiac events in AKI conditions.
Assuntos
Injúria Renal Aguda , Cálcio , Injúria Renal Aguda/etiologia , Animais , Arritmias Cardíacas , Biomarcadores/metabolismo , Cálcio/metabolismo , Cardiomegalia/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Minerais/metabolismo , Miócitos Cardíacos/fisiologia , Fósforo/metabolismo , Estudos Retrospectivos , Troponina T/metabolismoRESUMO
The synthesis, structure, theoretical and experimental in vitro antioxidant properties using the DPPH, ORAC, and benzoic acid, as well as preliminary in vitro pharmacological activities of (Z)-α-aryl and heteroaryl N-alkyl-nitrones 6-15, 18, 19, 21, and 23, is reported. In the in vitro antioxidant activity, for the DPPH radical test, only nitrones bearing free phenol groups gave the best RSA (%) values, nitrones 13 and 14 showing the highest values in this assay. In the ORAC analysis, the most potent radical scavenger was nitrone indole 21, followed by the N-benzyl benzene-type nitrones 10 and 15. Interestingly enough, the archetypal nitrone 7 (PBN) gave a low RSA value (1.4%) in the DPPH test, or was inactive in the ORAC assay. Concerning the ability to scavenge the hydroxyl radical, all the nitrones studied proved active in this experiment, showing high values in the 94-97% range, the most potent being nitrone 14. The theoretical calculations for the prediction of the antioxidant power, and the potential of ionization confirm that nitrones 9 and 10 are among the best compounds in electron transfer processes, a result that is also in good agreement with the experimental values in the DPPH assay. The calculated energy values for the reaction of ROS (hydroxyl, peroxyl) with the nitrones predict that the most favourable adduct-spin will take place between nitrones 9, 10, and 21, a fact that would be in agreement with their experimentally observed scavenger ability. The in vitro pharmacological analysis showed that the neuroprotective profile of the target molecules was in general low, with values ranging from 0% to 18.7%, in human neuroblastoma cells stressed with a mixture of rotenone/oligomycin-A, being nitrones 18, and 6-8 the most potent, as they show values in the range 24-18.4%.
Assuntos
Antioxidantes/síntese química , Isquemia Encefálica/tratamento farmacológico , Óxidos de Nitrogênio/química , Antioxidantes/química , Antioxidantes/uso terapêutico , Linhagem Celular Tumoral , Humanos , Ligação de Hidrogênio , Radical Hidroxila/metabolismo , Modelos Teóricos , Óxidos de Nitrogênio/síntese química , Óxidos de Nitrogênio/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , TermodinâmicaRESUMO
The synthesis, biological assessment, and molecular modelling of new tacrine analogues 11-22 is described. Compounds 11-22 have been obtained by Friedländer-type reaction of 2-aminopyridine-3-carbonitriles 1-10 with cyclohexanone or 1-benzyl-4-piperidone. The biological evaluation showed that some of these molecules were good AChE inhibitors, in the nanomolar range, and quite selective regarding the inhibition of BuChE, the most potent being 5-amino-2-(dimethylamino)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (11) [IC(50) (EeAChE: 14nM); IC(50) (eqBuChE: 5.2µM]. Kinetic studies on the easily available and potent anticholinesterasic compound 5-amino-2-(methoxy)-6,7,8,9-tetrahydrobenzo[1,8-b]-naphthyridine-3-carbonitrile (16) [IC(50) (EeAChE: 64nM); IC(50) (eqBuChE: 9.6µM] showed that this compound is a mixed-type inhibitor (K(i)=69.2nM) of EeAChE. Molecular modelling on inhibitor 16 confirms that this compound, as expected and similarly to tacrine, binds at the catalytic active site of EeAChE. The neuroprotective profile of molecules 11-22 has been investigated in SH-SY5Y neuroblastoma cells stressed with a mixture of oligomycin-A/rotenone. Compound 16 was also able to rescue by 50% cell death induced by okadaic acid in SH-SY5Y cells. From these results we conclude that the neuroprotective profile of these molecules is moderate, the most potent being compounds 12 and 17 which reduced cell death by 29%. Compound 16 does not affect ACh- nor K(+)-induced calcium signals in bovine chromaffin cells. Consequently, tacrine analogues 11-22 can be considered attractive therapeutic molecules on two key pharmacological targets playing key roles in the progression of Alzheimer, that is, cholinergic dysfunction and oxidative stress, as well as in neuronal cerebrovascular diseases.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Nitrilas/química , Tacrina/análogos & derivados , Doenças Vasculares/tratamento farmacológico , Acetilcolinesterase/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/uso terapêutico , Humanos , Cinética , Modelos Moleculares , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/químicaRESUMO
Cardiorenal syndrome (CRS) is a complex disorder that refers to the category of acute or chronic kidney diseases that induce cardiovascular disease, and inversely, acute or chronic heart diseases that provoke kidney dysfunction. There is a close relationship between renal and cardiovascular disease, possibly due to the presence of common risk factors for both diseases. Thus, it is well known that renal diseases are associated with increased risk of developing cardiovascular disease, suffering cardiac events and even mortality, which is aggravated in those patients with end-stage renal disease or who are undergoing dialysis. Recent works have proposed mineral bone disorders (MBD) as the possible link between kidney dysfunction and the development of cardiovascular outcomes. Traditionally, increased serum phosphate levels have been proposed as one of the main factors responsible for cardiovascular damage in kidney patients. However, recent studies have focused on other MBD components such as the elevation of fibroblast growth factor (FGF)-23, a phosphaturic bone-derived hormone, and the decreased expression of the anti-aging factor Klotho in renal patients. It has been shown that increased FGF-23 levels induce cardiac hypertrophy and dysfunction and are associated with increased cardiovascular mortality in renal patients. Decreased Klotho expression occurs as renal function declines. Despite its expression being absent in myocardial tissue, several studies have demonstrated that this antiaging factor plays a cardioprotective role, especially under elevated FGF-23 levels. The present review aims to collect the recent knowledge about the FGF-23-Klotho axis in the connection between kidney and heart, focusing on their specific role as new therapeutic targets in CRS.
RESUMO
Fibroblast growth factor-23 (FGF)-23 is a phosphaturic hormone involved in mineral bone metabolism that helps control phosphate homeostasis and reduces 1,25-dihydroxyvitamin D synthesis. Recent data have highlighted the relevant direct FGF-23 effects on the myocardium, and high plasma levels of FGF-23 have been associated with adverse cardiovascular outcomes in humans, such as heart failure and arrhythmias. Therefore, FGF-23 has emerged as a novel biomarker of cardiovascular risk in the last decade. Indeed, experimental data suggest FGF-23 as a direct mediator of cardiac hypertrophy development, cardiac fibrosis and cardiac dysfunction via specific myocardial FGF receptor (FGFR) activation. Therefore, the FGF-23/FGFR pathway might be a suitable therapeutic target for reducing the deleterious effects of FGF-23 on the cardiovascular system. More research is needed to fully understand the intracellular FGF-23-dependent mechanisms, clarify the downstream pathways and identify which could be the most appropriate targets for better therapeutic intervention. This review updates the current knowledge on both clinical and experimental studies and highlights the evidence linking FGF-23 to cardiovascular events. The aim of this review is to establish the specific role of FGF-23 in the heart, its detrimental effects on cardiac tissue and the possible new therapeutic opportunities to block these effects.
RESUMO
Aging and chronic kidney disease (CKD) are important interrelated cardiovascular risk (CVR) factors linked to oxidative stress, but this relationship has not been well studied in older adults. We assessed the global oxidative status in an older population with normal to severely impaired renal function. We determined the oxidative status of 93 older adults (mean age 85 years) using multimarker scores. OxyScore was computed as index of systemic oxidative damage by analyzing carbonyl groups, oxidized low-density lipoprotein, 8-hydroxy-2'-deoxyguanosine, and xanthine oxidase activity. AntioxyScore was computed as index of antioxidant defense by analyzing catalase and superoxide dismutase (SOD) activity and total antioxidant capacity. OxyScore and AntioxyScore were higher in subjects with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 than in peers with eGFR >60 mL/min/1.73 m2, with protein carbonyls, catalase, and SOD activity as major drivers. Older adults with a recent cardiovascular event had similar OxyScore and AntioxyScore as peers with eGFR >60 mL/min/1.73 m2. Multivariate linear regression analysis revealed that both indices were associated with decreased eGFR independently of traditional CVR factors. Interestingly, AntioxyScore was also associated with diuretic treatment, and a more pronounced increase was seen in subjects receiving combination therapy. The associations of AntioxyScore with diuretic treatment and eGFR were mutually independent. In conclusion, eGFR is the major contributor to the imbalance in oxidative stress in this older population. Given the association between oxidative stress, CKD, and CVR, the inclusion of renal function parameters in CVR estimators for older populations, such as the SCORE-OP, might improve their modest performance.
Assuntos
Antioxidantes/metabolismo , Biomarcadores/metabolismo , Diuréticos/efeitos adversos , Estresse Oxidativo , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , EspanhaRESUMO
The synthesis, molecular modeling, and pharmacological analysis of new multipotent simple, and readily available 2-aminopyridine-3,5-dicarbonitriles (3-20), and 2-chloropyridine-3,5-dicarbonitriles (21-28), prepared from 2-amino-6-chloropyridine-3,5-dicarbonitrile (1) and 2-amino-6-chloro-4-phenylpyridine-3,5-dicarbonitrile (2) is described. The biological evaluation showed that some of these molecules were modest inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), in the micromolar range. The 2-amino (3, 4), and 2-chloro derivatives 21-23, 25, 26 were AChE selective inhibitors, whereas 2-amino derivatives 5, 14 proved to be selective for BuChE. Only inhibitor 24 was equipotent for both cholinesterases. Kinetic studies on compound 23 showed that this compound is a mixed-type inhibitor of AChE showing a K(i) of 6.33 microM. No clear SAR can be obtained form these data, but apparently, compounds bearing small groups such as the N,N'-dimethylamino or the pyrrolidino, regardless of the presence of a 2-amino, or 6-chloro substituent in the pyridine ring, preferentially inhibit AChE. Molecular modeling on inhibitors 4, 5, 22, and 23 has been carried out to give a better insight into the binding mode on the catalytic active site (CAS), and peripheral anionic site (PAS) of AChE. The most important differences in the observed binding relay on the modifications of the group at C2, as the amino group forms two hydrogen bonds that direct the binding mode, while in the case of compounds with a chlorine atom, this is not possible. The neuroprotective profile of these molecules has been investigated. In the LDH test, only compounds 26, 3, 22, and 24 showed neuroprotection with values in the range 37.8-31.6% in SH-SY5Y neuroblastoma cells stressed with a mixture of oligomycin-A/rotenone, but in the MTT test only compound 17 (32.9%) showed a similar profile. Consequently, these compounds can be considered as attractive multipotent therapeutic molecules on two key pharmacological receptors playing key roles in the progress of Alzheimer, that is, cholinergic dysfunction and oxidative stress, and neuronal vascular diseases.
Assuntos
Aminopiridinas/química , Aminopiridinas/farmacologia , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Nitrilas/química , Nitrilas/farmacologia , Piridinas/química , Piridinas/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Aminopiridinas/síntese química , Animais , Butirilcolinesterase/metabolismo , Linhagem Celular Tumoral , Colinérgicos/síntese química , Colinérgicos/química , Colinérgicos/farmacologia , Inibidores da Colinesterase/síntese química , Electrophorus , Cavalos , Humanos , Modelos Moleculares , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/síntese química , Nitrilas/síntese química , Piridinas/síntese química , Doenças Vasculares/tratamento farmacológicoRESUMO
BACKGROUND AND PURPOSE: Klotho is a membrane-bound or soluble protein, originally identified as an age-suppressing factor and regulator of mineral metabolism. Klotho deficiency is associated with the development of renal disease, but its role in cardiac function in the context of uraemic cardiomyopathy is unknown. EXPERIMENTAL APPROACH: We explored the effects of Klotho on cardiac Ca2+ cycling. We analysed Ca2+ handling in adult cardiomyocytes from Klotho-deficient (kl/kl) mice and from a murine model of 5/6 nephrectomy (Nfx). We also studied the effect of exogenous Klotho supplementation, by chronic recombinant Klotho treatment, or endogenous Klotho overexpression, using transgenic mice overexpressing Klotho (Tg-Kl), on uraemic cardiomyopathy. Hearts from Nfx mice were used to study Ca2+ sensitivity of ryanodine receptors and their phosphorylation state. KEY RESULTS: Cardiomyocytes from kl/kl mice showed decreased amplitude of intracellular Ca2+ transients and cellular shortening together with an increase in pro-arrhythmic Ca2+ events compared with cells from wild-type mice. Cardiomyocytes from Nfx mice exhibited the same impairment in Ca2+ cycling as kl/kl mice. Changes in Nfx cardiomyocytes were explained by higher sensitivity of ryanodine receptors to Ca2+ and their increased phosphorylation at the calmodulin kinase type II and protein kinase A sites. Ca2+ mishandling in Nfx-treated mice was fully prevented by chronic recombinant Klotho administration or transgenic Klotho overexpression. CONCLUSIONS AND IMPLICATIONS: Klotho emerges as an attractive therapeutic tool to improve cardiac Ca2+ mishandling observed in uraemic cardiomyopathy. Strategies that improve Klotho availability are good candidates to protect the heart from functional cardiac alterations in renal disease.
Assuntos
Cálcio , Cardiomiopatias , Animais , Cálcio/metabolismo , Cardiomiopatias/prevenção & controle , Glucuronidase , Proteínas Klotho , Camundongos , Camundongos Transgênicos , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de RianodinaRESUMO
Oxidized low-density lipoprotein (oxLDL) is associated with cardiac damage and causes injury to multiple cell types. We aimed to investigate the role of oxLDL in ventricular stress. We first examined the association between circulating oxLDL and N-terminal pro-brain natriuretic peptide (NT-proBNP), a marker of myocardial stress, in young subjects (30-50 years) with or without stable coronary artery disease (SCAD). oxLDL and NT-proBNP were significantly higher in subjects at high cardiovascular risk (CVR) than in subjects at low CVR and were associated independently of traditional CVR factors and C-reactive protein. Furthermore, the levels of oxLDL and NT-proBNP were significantly lower in subjects with SCAD than in peers at high CVR. To determine the intracellular mechanisms involved in the cardiac effects of oxLDL, we analyzed the in vitro effect of oxLDL on intracellular Ca2+ handling in adult rat ventricular cardiomyocytes using confocal microscopy. Acute challenge of adult ventricular cardiomyocytes to oxLDL reduced systolic Ca2+ transients and sarcoplasmic reticulum Ca2+ load. Moreover, diastolic spontaneous Ca2+ leak increased significantly after acute exposure to oxLDL. Thus, we demonstrate that oxLDL associates with NT-proBNP in young subjects, and can directly induce Ca2+ mishandling in adult ventricular cardiomyoyctes, predisposing cardiomyocytes to cardiac dysfunction and arrhythmogenicity.
RESUMO
Cardiovascular risk (CVR) tends to be estimated in the short-term, which underestimates lifetime (LT)-CVR of young subjects. We determined whether LT-CVR is associated with a multimarker score of oxidative status in young adults and whether this association is independent of traditional CVR factors. Seventy-two young adults were stratified into: (1) low or (2) high LT-CVR, and (3) stable coronary artery disease (SCAD). CVR was estimated with QRisk and atherosclerotic CV disease (ASCVD) risk estimators, or second manifestations of arterial disease (SMART). Risk score. oxidative damage was determined by measuring carbonyls, oxidized LDL (oxLDL), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and xanthine oxidase activity. Antioxidant defence was determined by total antioxidant capacity (TAC), catalase (CAT) activity and superoxide dismutase (SOD) activity. Multimarker scores of systemic oxidative damage (OxyScore) and antioxidant defence (AntioxyScore) were computed as standardized variables. Subjects with high LT-CVR had significantly higher levels of oxLDL, 8-OHdG, TAC, and CAT activity than subjects with low LT-CVR or with SCAD. QRisk and ASCVD estimators correlated positively with oxLDL, TAC, and CAT activity, while SMART Risk Score correlated with carbonyls and SOD activity. OxyScore and AntioxyScore were significantly higher in subjects with high LT-CVR than with low LT-CVR or with SCAD. OxyScore, but not AntioxyScore, was associated with LT-CVR independently of each traditional CVR factor. This study for the first time demonstrates a positive association between oxidative stress and the risk of first and recurrent CV events in young adults.
Assuntos
Doenças Cardiovasculares/etiologia , Estresse Oxidativo , Adulto , Biomarcadores/sangue , Biomarcadores/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Hemodialysis patients experience high oxidative stress because of systemic inflammation and depletion of antioxidants. Little is known about the global oxidative status during dialysis or whether it is linked to the type of dialysis. We investigated the oxidative status before (pre-) and after (post-) one dialysis session in patients subjected to high-flux dialysis (HFD) or on-line hemodiafiltration (OL-HDF). We analyzed carbonyls, oxidized LDL (oxLDL), 8-hydroxy-2'-deoxyguanosine, and xanthine oxidase (XOD) activity as oxidative markers, and total antioxidant capacity (TAC), catalase, and superoxide dismutase activities as measures of antioxidant defense. Indices of oxidative damage (OxyScore) and antioxidant defense (AntioxyScore) were computed and combined into a global DialysisOxyScore. Both dialysis modalities cleared all markers (p < 0.01) except carbonyls, which were unchanged, and oxLDL, which increased post-dialysis (p < 0.01). OxyScore increased post-dialysis (p < 0.001), whereas AntioxyScore decreased (p < 0.001). XOD and catalase activities decreased post-dialysis after OL-HDF (p < 0.01), and catalase activity was higher after OL-HDF than after HFD (p < 0.05). TAC decreased in both dialysis modalities (p < 0.01), but remained higher in OL-HDF than in HFD post-dialysis (p < 0.05), resulting in a lower overall DialysisOxyScore (p < 0.05). Thus, patients on OL-HDF maintain higher levels of antioxidant defense, which might balance the elevated oxidative stress during dialysis, although further longitudinal studies are needed.