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1.
Kidney360 ; 3(9): 1529-1541, 2022 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-36245643

RESUMO

Background: Fibroblast growth factor 23 (FGF23) is a bone-derived phosphatonin that is elevated in chronic kidney disease (CKD) and has been implicated in the development of cardiovascular disease. It is unknown whether elevated FGF23 in CKD is associated with impaired cardiovascular functional capacity, as assessed by maximum exercise oxygen consumption (VO2Max). We sought to determine whether FGF23 is associated with cardiovascular functional capacity in patients with advanced CKD and after improvement of VO2Max by kidney transplantation. Methods: We performed secondary analysis of 235 patients from the Cardiopulmonary Exercise Testing in Renal Failure and After Kidney Transplantation (CAPER) cohort, which recruited patients with stage 5 CKD who underwent kidney transplantation or were waitlisted and hypertensive controls. All patients underwent cardiopulmonary exercise testing (CPET) and echocardiography and were followed longitudinally for 1 year after study enrollment. Results: Patients across FGF23 quartiles differed in BMI (P=0.004) and mean arterial pressure (P<0.001) but did not significantly differ in sex (P=0.5) or age (P=0.08) compared with patients with lower levels of FGF23. Patients with higher FGF23 levels had impaired VO2Max (Q1: 24.2±4.8 ml/min per kilogram; Q4: 18.6±5.2 ml/min per kilogram; P<0.001), greater left ventricular mass index (LVMI; P<0.001), reduced HR at peak exercise (P<0.001), and maximal workload (P<0.001). Kidney transplantation conferred a significant decline in FGF23 at 2 months (P<0.001) before improvement in VO2Max at 1 year (P=0.008). Multivariable regression modeling revealed that changes in FGF23 was significantly associated with VO2Max in advanced CKD (P<0.001) and after improvement after kidney transplantation (P=0.006). FGF23 was associated with LVMI before kidney transplantation (P=0.003), however this association was lost after adjustment for dialysis status (P=0.4). FGF23 was not associated with LVMI after kidney transplantation in all models. Conclusions: FGF23 levels are associated with alterations in cardiovascular functional capacity in advanced CKD and after kidney transplantation. FGF23 is only associated with structural cardiac adaptations in advanced CKD but this was modified by dialysis status, and was not associated after kidney transplantation.


Assuntos
Falência Renal Crônica , Transplante de Rim , Insuficiência Renal Crônica , Humanos , Ecocardiografia , Fatores de Crescimento de Fibroblastos/metabolismo , Falência Renal Crônica/cirurgia , Insuficiência Renal Crônica/complicações
2.
J Am Heart Assoc ; 11(14): e025656, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35861826

RESUMO

Background The transition to dialysis period carries a substantial increased cardiovascular risk in patients with chronic kidney disease. Despite this, alterations in cardiovascular functional capacity during this transition are largely unknown. The present study therefore sought to assess ventilatory exercise response measures in patients within 1 year of initiating dialysis. Methods and Results We conducted a cross-sectional study of 241 patients with chronic kidney disease stage 5 from the CAPER (Cardiopulmonary Exercise Testing in Renal Failure) study and from the intradialytic low-frequency electrical muscle stimulation pilot randomized controlled trial cohorts. Patients underwent cardiopulmonary exercise testing and echocardiography. Of the 241 patients (age, 48.9 [15.0] years; 154 [63.9%] men), 42 were predialytic (mean estimated glomerular filtration rate, 14 mL·min-1·1.73 m-2), 54 had a dialysis vintage ≤12 months, and 145 had a dialysis vintage >12 months. Dialysis vintage ≤12 months exhibited a significantly impaired cardiovascular functional capacity, as assessed by oxygen uptake at peak exercise (18.7 [5.8] mL·min-1·kg-1) compared with predialysis (22.7 [5.2] mL·min-1·kg-1; P<0.001). Dialysis vintage ≤12 months also exhibited reduced peak workload, impaired peak heart rate, reduced circulatory power, and increased left ventricular mass index (P<0.05 for all) compared with predialysis. After excluding those with prior kidney transplant, dialysis vintage >12 months exhibited a lower oxygen uptake at peak exercise (17.0 [4.9] mL·min-1·kg-1) compared with dialysis vintage ≤12 months (18.9 [5.9] mL·min-1·kg-1; P=0.033). Conclusions Initiating dialysis is associated with a significant impairment in oxygen uptake at peak exercise and overall decrements in ventilatory and hemodynamic exercise responses that predispose patients to functional dependence. The magnitude of these changes is comparable to the differences between low-risk New York Heart Association class I and higher-risk New York Heart Association class II to IV heart failure.


Assuntos
Insuficiência Cardíaca , Falência Renal Crônica , Insuficiência Renal Crônica , Estudos Transversais , Teste de Esforço , Tolerância ao Exercício , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/terapia , Humanos , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Oxigênio , Consumo de Oxigênio , Diálise Renal/efeitos adversos , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/terapia
3.
J Am Heart Assoc ; 11(5): e022991, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35179046

RESUMO

Background The myocardial cytoskeleton functions as the fundamental framework critical for organelle function, bioenergetics and myocardial remodeling. To date, impairment of the myocardial cytoskeleton occurring in the failing heart in patients with advanced chronic kidney disease has been largely undescribed. Methods and Results We conducted a 3-arm cross-sectional cohort study of explanted human heart tissues from patients who are dependent on hemodialysis (n=19), hypertension (n=10) with preserved renal function, and healthy controls (n=21). Left ventricular tissues were subjected to pathologic examination and next-generation RNA sequencing. Mechanistic and interference RNA studies utilizing in vitro human cardiac fibroblast models were performed. Left ventricular tissues from patients undergoing hemodialysis exhibited increased myocardial wall thickness and significantly greater fibrosis compared with hypertension patients (P<0.05) and control (P<0.01). Transcriptomic analysis revealed that the focal adhesion pathway was significantly enriched in hearts from patients undergoing hemodialysis. Hearts from patients undergoing hemodialysis exhibited dysregulated components of the focal adhesion pathway including reduced ß-actin (P<0.01), ß-tubulin (P<0.01), vimentin (P<0.05), and increased expression of vinculin (P<0.05) compared with controls. Cytoskeletal adaptations in hearts from the hemodialysis group were associated with impaired mitochondrial bioenergetics, including dysregulated mitochondrial dynamics and fusion, and loss of cell survival pathways. Mechanistic studies revealed that cytoskeletal changes can be driven by uremic and metabolic abnormalities of chronic kidney disease, in vitro. Furthermore, focal adhesion kinase silencing via interference RNA suppressed major cytoskeletal proteins synergistically with mineral stressors found in chronic kidney disease in vitro. Conclusions Myocardial failure in advanced chronic kidney disease is characterized by impairment of the cytoskeleton involving disruption of the focal adhesion pathway, mitochondrial failure, and loss of cell survival pathways.


Assuntos
Hipertensão , Insuficiência Renal Crônica , Estudos Transversais , Citoesqueleto , Humanos , Rim/fisiologia , RNA , Insuficiência Renal Crônica/terapia
4.
J Am Soc Nephrol ; 33(3): 565-582, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35091451

RESUMO

BACKGROUND: Endothelial cell injury is a common nidus of renal injury in patients and consistent with the high prevalence of AKI reported during the coronavirus disease 2019 pandemic. This cell type expresses integrin α5 (ITGA5), which is essential to the Tie2 signaling pathway. The microRNA miR-218-5p is upregulated in endothelial progenitor cells (EPCs) after hypoxia, but microRNA regulation of Tie2 in the EPC lineage is unclear. METHODS: We isolated human kidney-derived EPCs (hkEPCs) and surveyed microRNA target transcripts. A preclinical model of ischemic kidney injury was used to evaluate the effect of hkEPCs on capillary repair. We used a genetic knockout model to evaluate the effect of deleting endogenous expression of miR-218 specifically in angioblasts. RESULTS: After ischemic in vitro preconditioning, miR-218-5p was elevated in hkEPCs. We found miR-218-5p bound to ITGA5 mRNA transcript and decreased ITGA5 protein expression. Phosphorylation of 42/44 MAPK decreased by 73.6% in hkEPCs treated with miR-218-5p. Cells supplemented with miR-218-5p downregulated ITGA5 synthesis and decreased 42/44 MAPK phosphorylation. In a CD309-Cre/miR-218-2-LoxP mammalian model (a conditional knockout mouse model designed to delete pre-miR-218-2 exclusively in CD309+ cells), homozygotes at e18.5 contained avascular glomeruli, whereas heterozygote adults showed susceptibility to kidney injury. Isolated EPCs from the mouse kidney contained high amounts of ITGA5 and showed decreased migratory capacity in three-dimensional cell culture. CONCLUSIONS: These results demonstrate the critical regulatory role of miR-218-5p in kidney EPC migration, a finding that may inform efforts to treat microvascular kidney injury via therapeutic cell delivery.


Assuntos
Injúria Renal Aguda/etiologia , Injúria Renal Aguda/metabolismo , Células Progenitoras Endoteliais/metabolismo , Células Progenitoras Endoteliais/patologia , Integrina alfa5/metabolismo , MicroRNAs/fisiologia , Injúria Renal Aguda/patologia , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor TIE-2/fisiologia , Transdução de Sinais/fisiologia
5.
Kidney Int ; 98(5): 1225-1241, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32610050

RESUMO

Polycystin-1 (PC1) and -2 (PC2), products of the PKD1 and PKD2 genes, are mutated in autosomal dominant polycystic kidney disease (ADPKD). They localize to the primary cilia; however, their ciliary function is in dispute. Loss of either the primary cilia or PC1 or PC2 causes cyst formation. However, loss of both cilia and PC1 or PC2 inhibits cyst growth via an unknown pathway. To help define a pathway, we studied cilium length in human and mouse kidneys. We found cilia are elongated in kidneys from patients with ADPKD and from both Pkd1 and Pkd2 knockout mice. Cilia elongate following polycystin inactivation. The role of intraflagellar transport proteins in Pkd1-deficient mice is also unknown. We found that inactivation of Ift88 (a gene expressing a core component of intraflagellar transport) in Pkd1 knockout mice, as well as in a new Pkd2 knockout mouse, shortened the elongated cilia, impeded kidney and liver cystogenesis, and reduced cell proliferation. Multi-stage in vivo analysis of signaling pathways revealed ß-catenin activation as a prominent, early, and sustained event in disease onset and progression in Pkd2 single knockout but not in Pkd2.Ift88 double knockout mouse kidneys. Additionally, AMPK, mTOR and ERK pathways were altered in Pkd2 single knockout mice but only AMPK and mTOR pathway alteration were rescued in Pkd2.Ift88 double knockout mice. Thus, our findings advocate an essential role of polycystins in the structure and function of the primary cilia and implicate ß-catenin as a key inducer of cystogenesis downstream of the primary cilia. Our data suggest that modulating cilium length and/or its associated signaling events may offer novel therapeutic approaches for ADPKD.


Assuntos
Cistos , Doenças Renais Policísticas , Rim Policístico Autossômico Dominante , Animais , Cílios , Cistos/genética , Humanos , Rim , Fígado , Camundongos , Camundongos Knockout , Rim Policístico Autossômico Dominante/genética , Canais de Cátion TRPP/genética
6.
Kaohsiung J Med Sci ; 36(6): 389-392, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32492292

RESUMO

The spike glycoprotein on the virion surface docking onto the angiotensin-converting enzyme (ACE) 2 dimer is an essential step in the process of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in human cells-involves downregulation of ACE2 expression with systemic renin-angiotensin system (RAS) imbalance and promotion of multi-organ damage. In general, the RAS induces vasoconstriction, hypertension, inflammation, fibrosis, and proliferation via the ACE/Ang II/Ang II type 1 receptor (AT1R) axis and induces the opposite effects via the ACE2/Ang (1-7)/Mas axis. The RAS may be activated by chronic inflammation in hypertension, diabetes, obesity, and cancer. SARS-CoV-2 induces the ACE2 internalization and shedding, leading to the inactivation of the ACE2/Ang (1-7)/Mas axis. Therefore, we hypothesize that two hits to the RAS drives COVID-19 progression. In brief, the first hit originates from chronic inflammation activating the ACE/Ang II/AT1R axis, and the second originates from the COVID-19 infection inactivating the ACE2/Ang (1-7)/Mas axis. Moreover, the two hits to the RAS may be the primary reason for increased mortality in patients with COVID-19 who have comorbidities and may serve as a therapeutic target for COVID-19 treatment.


Assuntos
Betacoronavirus , Infecções por Coronavirus/fisiopatologia , Pneumonia Viral/fisiopatologia , Sistema Renina-Angiotensina/fisiologia , Angiotensina II/fisiologia , Antagonistas de Receptores de Angiotensina/uso terapêutico , Enzima de Conversão de Angiotensina 2 , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Betacoronavirus/patogenicidade , Betacoronavirus/fisiologia , COVID-19 , Comorbidade , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Humanos , Modelos Biológicos , Pandemias , Peptidil Dipeptidase A/fisiologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/epidemiologia , Receptor Tipo 1 de Angiotensina/fisiologia , Sistema Renina-Angiotensina/efeitos dos fármacos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/fisiologia
7.
Am J Pathol ; 190(3): 642-659, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31972158

RESUMO

Ischemia due to hypoperfusion is one of the most common forms of acute kidney injury. We hypothesized that kidney hypoxia initiates the up-regulation of miR-218 expression in endothelial progenitor cells (EPCs) to guide endocapillary repair. Murine renal artery-derived EPCs (CD34+/CD105-) showed down-regulation of mmu-Mir218-5p/U6 RNA ratio after ischemic injury, while in human renal arteries, MIR218-5p expression was up-regulated after ischemic injury. MIR218 expression was clarified in cell culture experiments in which increases in both SLIT3 and MIR218-2-5p expressions were observed after 5 minutes of hypoxia. ROBO1 transcript, a downstream target of MIR218-2-5p, showed inverse expression to MIR218-2-5p. EPCs transfected with a MIR218-5p inhibitor in three-dimensional normoxic culture showed premature capillary formation. Organized progenitor cell movement was reconstituted when cells were co-transfected with Dicer siRNA and low-dose Mir218-5p mimic. A Mir218-2 knockout was generated to assess the significance of miR-218-2 in a mammalian model. Mir218-2-5p expression was decreased in Mir218-2-/- embryos at E16.5. Mir218-2-/- decreased CD34+ angioblasts in the ureteric bud at E16.5 and were nonviable. Mir218-2+/- decreased peritubular capillary density at postnatal day 14 and increased serum creatinine after ischemia in adult mice. Systemic injection of miR-218-5p decreased serum creatinine after injury. These experiments demonstrate that miR-218 expression can be triggered by hypoxia and modulates EPC migration in the kidney.


Assuntos
Injúria Renal Aguda/patologia , Isquemia/patologia , MicroRNAs/genética , Proteínas do Tecido Nervoso/metabolismo , Receptores Imunológicos/metabolismo , Adulto , Idoso , Animais , RNA Helicases DEAD-box , Modelos Animais de Doenças , Células Progenitoras Endoteliais/patologia , Feminino , Humanos , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microvasos/patologia , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/genética , Receptores Imunológicos/genética , Ribonuclease III
8.
Int J Mol Sci ; 20(18)2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31546756

RESUMO

Accelerated vascular aging is a condition that occurs as a complication of several highly prevalent inflammatory conditions such as chronic kidney disease, cancer, HIV infection and diabetes. Age-associated vascular alterations underlie a continuum of expression toward clinically overt cardiovascular disease. This has contributed to the striking epidemiologic transition whereby such noncommunicable diseases have taken center stage as modern-day global epidemics and public health problems. The identification of α-Klotho, a remarkable protein that confers powerful anti-aging properties has stimulated significant interest. In fact, emerging data have provided fundamental rationale for Klotho-based therapeutic intervention for vascular diseases and multiple other potential indications. However, the application of such discoveries in Klotho research remains fragmented due to significant gaps in our molecular understanding of Klotho biology, as well as hurdles in clinical research and experimental barriers that must first be overcome. These advances will be critical to establish the scientific platform from which future Klotho-based interventional trials and therapeutic enterprises can be successfully launched.


Assuntos
Envelhecimento/metabolismo , Glucuronidase/metabolismo , Doenças Vasculares/metabolismo , Envelhecimento/patologia , Animais , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Diabetes Mellitus/terapia , Humanos , Proteínas Klotho , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/terapia , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/terapia , Doenças Vasculares/patologia , Doenças Vasculares/terapia
9.
Int J Biol Sci ; 15(7): 1533-1545, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31337982

RESUMO

Aims: Berberine (BBR) improves beta-cell function in Type 2 diabetes (T2D) because of its anti-apoptotic activity, and our laboratory developed a new preparation named Huang-Gui Solid Dispersion (HGSD) to improve the oral bioavailability of BBR. However, the mechanism by which BBR inhibits beta-cell apoptosis is unclear. We hypothesized that the Group VIA Ca2+-Independent Phospholipase A2 (iPLA2ß)/Cardiolipin(CL)/Opa1 signaling pathway could exert a protective role in T2D by regulating beta-cell apoptosis and that HGSD could inhibit ß-cell apoptosis through iPLA2ß/CL/Opa1 upregulation. Methods: We examined how iPLA2ß and BBR regulated apoptosis and insulin secretion through CL/Opa1 in vivo and in vitro. In in vitro studies, we developed Palmitate(PA)-induced apoptotic cell death model in mouse insulinoma cells (MIN6). iPLA2ß overexpression and silencing technology were used to examine how the iPLA2ß/CL/Opa1 interaction may play an important role in BBR treatment. In in vivo studies, db/db mice were used as a diabetic animal model. The pancreatic islet function and morphology, beta-cell apoptosis and mitochondrial injury were examined to explore the effects of HGSD. The expression of iPLA2ß/CL/Opa1 was measured to explore whether the signaling pathway was damaged in T2D and was involved in HGSD treatment. Results: The overexpression of iPLA2ß and BBR treatment significantly attenuated Palmitate- induced mitochondrial injury and apoptotic death compared with Palmitate-treated MIN6 cell. In addition, iPLA2ß silencing could simultaneously partly abolish the anti-apoptotic effect of BBR and decrease CL/Opa1 signaling in MIN6 cells. Moreover, HGSD treatment significantly decreased beta-cell apoptosis and resulted in the upregulation of iPLA2ß/CL/Opa1 compared to those of the db/db mice. Conclusion: The results indicated that the regulation of iPLA2ß/CL/Opa1 by HGSD may prevent beta-cell apoptosis and may improve islet beta-cell function in Type 2 diabetic mice and in palmitate-treated MIN6 cells.


Assuntos
Apoptose , Berberina/farmacologia , Cardiolipinas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Fosfolipases A2 do Grupo VI/metabolismo , Animais , Linhagem Celular , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Inativação Gênica , Teste de Tolerância a Glucose , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Masculino , Medicina Tradicional Chinesa , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Palmitatos , Transdução de Sinais
10.
Nephrol Dial Transplant ; 33(6): 923-934, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29244159

RESUMO

Background: Chronic kidney disease (CKD) patients have deficient levels of glutathione peroxidase-3 (GPx3). We hypothesized that GPx3 deficiency may lead to cardiovascular disease in the presence of chronic kidney disease due to an accumulation of reactive oxygen species and decreased microvascular perfusion of the myocardium. Methods. To isolate the exclusive effect of GPx3 deficiency in kidney disease-induced cardiac disease, we studied the GPx3 knockout mouse strain (GPx3-/-) in the setting of surgery-induced CKD. Results. Ribonucleic acid (RNA) microarray screening of non-stimulated GPx3-/- heart tissue show increased expression of genes associated with cardiomyopathy including myh7, plac9, serpine1 and cd74 compared with wild-type (WT) controls. GPx3-/- mice underwent surgically induced renal mass reduction to generate a model of CKD. GPx3-/- + CKD mice underwent echocardiography 4 weeks after injury. Fractional shortening (FS) was decreased to 32.9 ± 5.8% in GPx3-/- + CKD compared to 62.0% ± 10.3 in WT + CKD (P < 0.001). Platelet aggregates were increased in the myocardium of GPx3-/- + CKD. Asymmetric dimethylarginine (ADMA) levels were increased in both GPx3-/- + CKD and WT+ CKD. ADMA stimulated spontaneous platelet aggregation more quickly in washed platelets from GPx3-/-. In vitro platelet aggregation was enhanced in samples from GPx3-/- + CKD. Platelet aggregation in GPx3-/- + CKD samples was mitigated after in vivo administration of ebselen, a glutathione peroxidase mimetic. FS improved in GPx3-/- + CKD mice after ebselen treatment. Conclusion: These results suggest GPx3 deficiency is a substantive contributing factor to the development of kidney disease-induced cardiac disease.


Assuntos
Modelos Animais de Doenças , Glutationa Peroxidase/fisiologia , Cardiopatias/etiologia , Agregação Plaquetária , Insuficiência Renal Crônica/complicações , Trombose/etiologia , Disfunção Ventricular Esquerda/etiologia , Animais , Arginina/análogos & derivados , Arginina/metabolismo , Cardiopatias/metabolismo , Cardiopatias/patologia , Camundongos , Camundongos Knockout , Espécies Reativas de Oxigênio/metabolismo , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Trombose/metabolismo , Trombose/patologia , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/patologia
11.
PLoS One ; 12(5): e0176817, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28463984

RESUMO

Endothelial cells (ECs) express fibroblast growth factor (FGF) receptors and are metabolically active after treatment with FGF-23. It is not known if this effect is α-Klotho independent or mediated by humoral or endogenous endothelial α-Klotho. In the present study, we aimed to characterize EC α-Klotho expression within the human vascular tree and to investigate the potential role of α-Klotho in determining FGF-23 mediated EC regulation. Human tissue and ECs from various organs were used for immunohistochemistry and Western blot. Primary cultures of human aortic endothelial cells (HAECs) and human brain microvascular endothelial cells (HBMECs) were used to generate in vitro cell models. We found endogenous α-Klotho expression in ECs from various organs except in microvascular ECs from human brain. Furthermore, FGF-23 stimulated endothelial nitric oxide synthase (eNOS) expression, nitric oxide (NO) production, and cell proliferation in HAECs. Interestingly, these effects were not observed in our HBMEC model in vitro. High phosphate treatment and endothelial α-Klotho knockdown mitigated FGF-23 mediated eNOS induction, NO production, and cell proliferation in HAECs. Rescue treatment with soluble α-Klotho did not reverse endothelial FGF-23 resistance caused by reduced or absent α-Klotho expression in HAECs. These novel observations provide evidence for differential α-Klotho functional expression in the human endothelium and its presence may play a role in determining the response to FGF-23 in the vascular tree. α-Klotho was not detected in cerebral microvascular ECs and its absence may render these cells nonresponsive to FGF-23.


Assuntos
Aorta/metabolismo , Células Endoteliais/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Glucuronidase/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Aorta/citologia , Encéfalo/irrigação sanguínea , Encéfalo/citologia , Encéfalo/metabolismo , Fármacos Cardiovasculares/administração & dosagem , Proliferação de Células/fisiologia , Células Cultivadas , Células Endoteliais/citologia , Fator de Crescimento de Fibroblastos 23 , Técnicas de Silenciamento de Genes , Glucuronidase/administração & dosagem , Glucuronidase/deficiência , Glucuronidase/genética , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imuno-Histoquímica , Proteínas Klotho , Microvasos/citologia , Microvasos/metabolismo , Óxido Nítrico/metabolismo , Fosfatos , RNA Interferente Pequeno , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Kidney Int ; 91(1): 129-143, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27692806

RESUMO

Vascular progenitor cells show promise for the treatment of microvasculature endothelial injury. We investigated the function of renal artery progenitor cells derived from radical nephrectomy patients, in animal models of acute ischemic and hyperperfusion injuries. Present in human adventitia, CD34positive/CD105negative cells were clonal and expressed transcription factors Sox2/Oct4 as well as surface markers CXCR4 (CD184)/KDR(CD309) consistent with endothelial progenitor cells. Termed renal artery-derived vascular progenitor cells (RAPC), injected cells were associated with decreased serum creatinine after ischemia/reperfusion, reduced albuminuria after hyperperfusion, and improved blood flow in both models. A small population of RAPC integrated with the renal microvasculature following either experimental injury. At a cellular level, RAPC promoted local endothelial migration in co-culture. Profiling of RAPC microRNA identified high levels of miRNA 218; also found at high levels in exosomes isolated from RAPC conditioned media after cell contact for 24 hours. After hydrogen peroxide-induced endothelial injury, RAPC exosomes harbored Robo-1 transcript; a gene known to be regulated by mir218. Such exosomes enhanced endothelial cell migration in culture in the absence of RAPC. Thus, our work shows the feasibility of pre-emptive pro-angiogenic progenitor cell procurement from a targeted patient population and potential therapeutic use in the form of autologous cell transplantation.


Assuntos
Injúria Renal Aguda/terapia , Capilares/fisiologia , Rim/patologia , Transplante de Células-Tronco/métodos , Células-Tronco/metabolismo , Cicatrização , Injúria Renal Aguda/induzido quimicamente , Animais , Antígenos CD34/metabolismo , Capilares/patologia , Movimento Celular , Técnicas de Cocultura , Creatinina/sangue , Modelos Animais de Doenças , Endoglina/metabolismo , Endotélio/citologia , Exossomos/metabolismo , Estudos de Viabilidade , Humanos , Peróxido de Hidrogênio/toxicidade , Rim/irrigação sanguínea , Camundongos , MicroRNAs/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores CXCR4/metabolismo , Receptores Imunológicos/metabolismo , Artéria Renal/citologia , Transplante Autólogo/métodos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
13.
J Cell Sci ; 129(19): 3675-3684, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27505895

RESUMO

Mutation of PKD1, encoding the protein polycystin-1 (PC1), is the main cause of autosomal dominant polycystic kidney disease (ADPKD). The signaling pathways downstream of PC1 in ADPKD are still not fully understood. Here, we provide genetic evidence for the necessity of Gα12 (encoded by Gna12, hereafter Gα12) for renal cystogenesis induced by Pkd1 knockout. There was no phenotype in mice with deletion of Gα12 (Gα12-/-). Polyinosine-polycytosine (pI:pC)-induced deletion of Pkd1 (Mx1Cre+Pkd1f/fGα12+/+) in 1-week-old mice resulted in multiple kidney cysts by 9 weeks, but the mice with double knockout of Pkd1 and Gα12 (Mx1Cre+Pkd1f/fGα12-/-) had no structural and functional abnormalities in the kidneys. These mice could survive more than one year without kidney abnormalities except multiple hepatic cysts in some mice, which indicates that the effect of Gα12 on cystogenesis is kidney specific. Furthermore, Pkd1 knockout promoted Gα12 activation, which subsequently decreased cell-matrix and cell-cell adhesion by affecting the function of focal adhesion and E-cadherin, respectively. Our results demonstrate that Gα12 is required for the development of kidney cysts induced by Pkd1 mutation in mouse ADPKD.


Assuntos
Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP/metabolismo , Rim/metabolismo , Rim/patologia , Rim Policístico Autossômico Dominante/metabolismo , Rim Policístico Autossômico Dominante/patologia , Canais de Cátion TRPP/metabolismo , Animais , Caderinas/metabolismo , Junções Célula-Matriz , Células Epiteliais/metabolismo , Deleção de Genes , Técnicas de Inativação de Genes , Fígado/metabolismo , Fígado/patologia , Camundongos , Modelos Biológicos , Fibras de Estresse/metabolismo
14.
Medicine (Baltimore) ; 95(11): e3067, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26986132

RESUMO

Nonapnea sleep disorders (NASDs) and associated problems, which are highly prevalent in patients with kidney diseases, are associated with unfavorable medical sequelae. Nonetheless, whether NASDs are associated with acute kidney injury (AKI) development has not been thoroughly analyzed. We examined the association between NASD and AKI. We conducted a population-based study by using 1,000,000 representative data from the Taiwan National Health Insurance Research Database for the period from January 1, 2000, to December 31, 2010. We studied the incidence and risk of AKI in 9178 newly diagnosed NASD patients compared with 27,534 people without NASD matched according to age, sex, index year, urbanization level, region of residence, and monthly income at a 1:3 ratio. The NASD cohort had an adjusted hazard ratio (hazard ratio [HR]; 95% confidence interval [CI] = 1.15-2.63) of subsequent AKI 1.74-fold higher than that of the control cohort. Older age and type 2 diabetes mellitus were significantly associated with an increased risk of AKI (P < 0.05). Among different types of NASDs, patients with insomnia had a 120% increased risk of developing AKI (95% CI = 1.38-3.51; P = 0.001), whereas patients with other sleep disorders had a 127% increased risk of subsequent AKI (95% CI = 1.07-4.80; P = 0.033). Men with NASDs were at a high risk of AKI (P < 0.05). This nationwide population-based cohort study provides evidence that patients with NASDs are at higher risk of developing AKI than people without NASDs.


Assuntos
Injúria Renal Aguda/epidemiologia , Transtornos do Sono-Vigília/complicações , Adulto , Fatores Etários , Idoso , Estudos de Coortes , Comorbidade , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Transtornos do Sono-Vigília/epidemiologia , Taiwan/epidemiologia
15.
J Vis Exp ; (109)2016 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-27022768

RESUMO

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is estimated to contribute to 19- 25% of all clinical cases of acute kidney injury (AKI) in critically ill patients. AKI detection has historically relied on metrics such as serum creatinine (sCr) or blood urea nitrogen (BUN) which are demonstrably inadequate in full assessment of nephrotoxicity in the early phase of renal dysfunction. Currently, there is no robust diagnostic method to accurately detect hemodynamic alteration in the early phase of AKI while such alterations might actually precede the rise in serum biomarker levels. Such early detection can help clinicians make an accurate diagnosis and help in in decision making for therapeutic strategy. Rats were treated with Cisplatin to induce AKI. Nephrotoxicity was assessed for six days using high-frequency sonography, sCr measurement and upon histopathology of kidney. Hemodynamic evaluation using 2D and Color-Doppler images were used to serially study nephrotoxicity in rats, using the sonography. Our data showed successful drug-induced kidney injury in adult rats by histological examination. Color-Doppler based sonographic assessment of AKI indicated that resistive-index (RI) and pulsatile-index (PI) were increased in the treatment group; and peak-systolic velocity (mm/s), end-diastolic velocity (mm/s) and velocity-time integral (VTI, mm) were decreased in renal arteries in the same group. Importantly, these hemodynamic changes evaluated by sonography preceded the rise of sCr levels. Sonography-based indices such as RI or PI can thus be useful predictive markers of declining renal function in rodents. From our sonography-based observations in the kidneys of rats that underwent AKI, we showed that these noninvasive hemodynamic measurements may consider as an accurate, sensitive and robust method in detecting early stage kidney dysfunction. This study also underscores the importance of ethical issues associated with animal use in research.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/diagnóstico por imagem , Antineoplásicos/toxicidade , Cisplatino/toxicidade , Rim/patologia , Ultrassonografia Doppler em Cores , Animais , Biomarcadores/sangue , Creatinina/sangue , Modelos Animais de Doenças , Hemodinâmica , Humanos , Rim/efeitos dos fármacos , Masculino , Ratos Sprague-Dawley
16.
J Clin Endocrinol Metab ; 100(10): E1308-18, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26280509

RESUMO

CONTEXT: α-Klotho has emerged as a powerful regulator of the aging process. To date, the expression profile of α-Klotho in human tissues is unknown, and its existence in some human tissue types is subject to much controversy. OBJECTIVE: This is the first study to characterize systemwide tissue expression of transmembrane α-Klotho in humans. We have employed next-generation targeted proteomic analysis using parallel reaction monitoring in parallel with conventional antibody-based methods to determine the expression and spatial distribution of human α-Klotho expression in health. RESULTS: The distribution of α-Klotho in human tissues from various organ systems, including arterial, epithelial, endocrine, reproductive, and neuronal tissues, was first identified by immunohistochemistry. Kidney tissues showed strong α-Klotho expression, whereas liver did not reveal a detectable signal. These results were next confirmed by Western blotting of both whole tissues and primary cells. To validate our antibody-based results, α-Klotho-expressing tissues were subjected to parallel reaction monitoring mass spectrometry (data deposited at ProteomeXchange, PXD002775) identifying peptides specific for the full-length, transmembrane α-Klotho isoform. CONCLUSIONS: The data presented confirm α-Klotho expression in the kidney tubule and in the artery and provide evidence of α-Klotho expression across organ systems and cell types that has not previously been described in humans.


Assuntos
Aorta/metabolismo , Córtex Cerebral/metabolismo , Glucuronidase/metabolismo , Rim/metabolismo , Células Epiteliais/metabolismo , Humanos , Proteínas Klotho , Neurônios/metabolismo , Proteômica
17.
Physiol Genomics ; 47(2): 24-32, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25492927

RESUMO

Interaction of polycystin-1 (PC1) and Gα12 is important for development of kidney cysts in autosomal dominant polycystic kidney disease (ADPKD). The integrity of cell polarity and cell-cell adhesions (mainly E-cadherin-mediated adherens junction) is altered in the renal epithelial cells of ADPKD. However, the key signaling pathway for this alteration is not fully understood. Madin-Darby canine kidney (MDCK) cells maintain the normal integrity of epithelial cell polarity and adherens junctions. Here, we found that deletion of Pkd1 increased activation of Gα12, which then promoted the cystogenesis of MDCK cells. The morphology of these cells was altered after the activation of Gα12. By using liquid chromatography-mass spectrometry, we found several proteins that could be related this change in the extracellular milieu. E-cadherin was one of the most abundant peptides after active Gα12 was induced. Gα12 activation or Pkd1 deletion increased the shedding of E-cadherin, which was mediated via increased ADAM10 activity. The increased shedding of E-cadherin was blocked by knockdown of ADAM10 or specific ADAM10 inhibitor GI254023X. Pkd1 deletion or Gα12 activation also changed the distribution of E-cadherin in kidney epithelial cells and caused ß-catenin to shift from cell membrane to nucleus. Finally, ADAM10 inhibitor, GI254023X, blocked the cystogenesis induced by PC1 knockdown or Gα12 activation in renal epithelial cells. Our results demonstrate that the E-cadherin/ß-catenin signaling pathway is regulated by PC1 and Gα12 via ADAM10. Specific inhibition of this pathway, especially ADAM10 activity, could be a novel therapeutic regimen for ADPKD.


Assuntos
Caderinas/metabolismo , Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP/metabolismo , Canais de Cátion TRPP/metabolismo , Proteínas ADAM/antagonistas & inibidores , Animais , Dipeptídeos/farmacologia , Cães , Células Epiteliais/metabolismo , Subunidades alfa G12-G13 de Proteínas de Ligação ao GTP/genética , Deleção de Genes , Humanos , Ácidos Hidroxâmicos/farmacologia , Rim/citologia , Rim/metabolismo , Células Madin Darby de Rim Canino/efeitos dos fármacos , Células Madin Darby de Rim Canino/metabolismo , Células Madin Darby de Rim Canino/patologia , Camundongos Knockout , Camundongos Transgênicos , Rim Policístico Autossômico Dominante/metabolismo , Rim Policístico Autossômico Dominante/patologia , Canais de Cátion TRPP/genética , beta Catenina/metabolismo
18.
Food Chem ; 167: 438-46, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25149009

RESUMO

With the prevalence of inflammatory bowel disease (IBD) and its associated risk for development of colorectal cancer, it is of great importance to prevent and treat IBD. However, due to the complexity of etiology and potentially serious adverse effects, treatment options for IBD are relatively limited. Thus, the purpose of this study was to identify a safe food-based approach for the prevention and treatment of IBD. In this study, we tested the effects of cranberry products on preventing dextran sulphate sodium-induced murine colitis. Our results suggest that both cranberry extract and dried cranberries-fed groups had a significantly reduced disease activity index, where dried cranberries were more effective in preventing colitis than cranberry extract. Shortening of colon length, colonic myeloperoxidase activity and production of pro-inflammatory cytokines were attenuated in animals fed dried cranberries compared to the controls. The current report suggests that cranberries can be applied to prevent and reduce the symptoms of IBD.


Assuntos
Colite/induzido quimicamente , Sulfato de Dextrana/química , Doenças Inflamatórias Intestinais/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Vaccinium macrocarpon/química , Animais , Masculino , Camundongos
19.
J Am Soc Nephrol ; 25(9): 1909-15, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24876120

RESUMO

Despite the increasing prevalence of CKD in the United States, there is a declining interest among United States medical graduates in nephrology as a career choice. Effective programs are needed to generate interest at early educational stages when career choices can be influenced. The Kidney Disease Screening and Awareness Program (KDSAP) is a novel program initiated at Harvard College that increases student knowledge of and interest in kidney health and disease, interest in nephrology career paths, and participation in kidney disease research. This model, built on physician mentoring, kidney screening of underserved populations, direct interactions with kidney patients, and opportunities to participate in kidney research, can be reproduced and translated to other workforce-challenged subspecialties.


Assuntos
Nefropatias/epidemiologia , Modelos Educacionais , Nefrologia/educação , Escolha da Profissão , Relações Comunidade-Instituição , Educação de Pós-Graduação em Medicina , Humanos , Programas de Rastreamento/métodos , Mentores , Apoio ao Desenvolvimento de Recursos Humanos , Estados Unidos/epidemiologia
20.
Cardiovasc Res ; 96(3): 524-32, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22933322

RESUMO

AIMS: Vascular calcification (VC) is a significant contributor to cardiovascular mortality in patients with chronic kidney disease (CKD) and coronary artery disease (CAD). Osteo/chondrocytic transformation and simultaneous dedifferentiation of smooth muscle cells (SMCs) are important in the pathogenesis of VC. Heat-shock protein 72 (HSP72) is a cardioprotective inducible heat-shock protein that functions as a molecular chaperone. However, its role in the development of accelerated vascular dysfunction and calcification is largely unexplored. METHODS AND RESULTS: We describe for the first time marked reduction in HSP72 expression in arteries from patients with CKD and CAD, compared with healthy controls, in vivo. Induction of HSP72 by heat-shock treatment (HST) significantly prevented the development of calcification of human aortic smooth muscle cells (HA-SMCs), in vitro. These anti-calcific effects were abolished following treatment with both quercetin, an HST inhibitor, and HSP72 siRNA knockdown. Induction of HSP72 suppressed Cbfa-1-dependent osteo/chondrocytic transformation and stabilized SMC contractile phenotype through the myocardin-serum response factor (SRF) pathway. Co-immunoprecipitation studies demonstrated physical association between SRF and HSP72. Furthermore, organ culture of arteries from CKD and CAD patients showed that these arteries retained their ability to induce HSP72 following HST, despite initially reduced expression. CONCLUSION: Our study shows for the first time that intracellular HSP72 may function as a central regulator of molecular pathways involved in the development of VC. We suggest treatment strategies that up-regulate HSP72 as a new approach to inhibit VC.


Assuntos
Doença da Artéria Coronariana/metabolismo , Proteínas de Choque Térmico HSP72/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Insuficiência Renal Crônica/metabolismo , Calcificação Vascular/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Células Cultivadas , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Doença da Artéria Coronariana/patologia , Feminino , Proteínas de Choque Térmico HSP72/antagonistas & inibidores , Proteínas de Choque Térmico HSP72/genética , Resposta ao Choque Térmico , Humanos , Masculino , 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 , Proteínas Nucleares/metabolismo , Técnicas de Cultura de Órgãos , Fenótipo , Quercetina/farmacologia , Interferência de RNA , RNA Mensageiro/metabolismo , Insuficiência Renal Crônica/patologia , Fator de Resposta Sérica/metabolismo , Transdução de Sinais , Transativadores/metabolismo , Transfecção , Regulação para Cima , Calcificação Vascular/genética , Calcificação Vascular/metabolismo , Calcificação Vascular/patologia , Adulto Jovem
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