RESUMO
ERK, an extracellular signal-regulated protein kinase, is involved in various biological responses, such as cell proliferation and differentiation, cell morphology maintenance, cytoskeletal construction, apoptosis, and canceration of cells. In this study, we focused on ERK pathway on cellular injury and autophagy-associated adaptive response in urinary protein-irritated renal tubular epithelial cells and explored the potential mechanisms underlying it. By using antioxidants N-acetylcysteine and catalase, we found that ERK pathway was activated by a reactive oxygen species- (ROS-) dependent mechanism after exposure to urinary proteins. What is more, ERK inhibitor U0126 could decrease the release of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and the number of apoptotic cells induced by urinary proteins, indicating the damaging effects of ERK pathway in mediating cellular injury and apoptosis in HK-2 cells. Interestingly, we also found that the increased expression of microtubule-associated protein 1 light chain 3 (LC3)-II (a key marker of autophagy) and the decreased expression of p62 (autophagic substrate) induced by urinary proteins were reversed by U0126, suggesting autophagy was activated by ERK pathway. Furthermore, rapamycin reduced urinary protein-induced NGAL and KIM-1 secretion and cell growth inhibition, while chloroquine played the opposite effect, indicating that autophagy activation by ERK pathway was an adaptive response in the exposure to urinary proteins. Taken together, our results indicate that activated ROS-ERK pathway can induce cellular injury and in the meantime provide an autophagy-associated adaptive response in urinary protein-irritated renal tubular epithelial cells.
Assuntos
Autofagia , Células Epiteliais/enzimologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Túbulos Renais Proximais/enzimologia , Nefrose Lipoide/enzimologia , Estresse Oxidativo , Proteinúria/enzimologia , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/farmacologia , Apoptose , Autofagia/efeitos dos fármacos , Proteínas Relacionadas à Autofagia/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Humanos , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/patologia , Nefrose Lipoide/patologia , Nefrose Lipoide/urina , Estresse Oxidativo/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteinúria/patologia , Proteinúria/urina , Transdução de SinaisRESUMO
This study investigated the molecular mechanisms underlying the antiproteinuric effect of DPP4 inhibition in 5/6 renal ablation rats and tested the hypothesis that the urinary activity of DPP4 correlates with chronic kidney disease (CKD) progression. Experiments were conducted in male Wistar rats who underwent 5/6 nephrectomy (Nx) or sham operation followed by 8 wk of treatment with the DPP4 inhibitor (DPP4i) sitagliptin or vehicle. Proteinuria increased progressively in Nx rats throughout the observation period. This increase was remarkably mitigated by sitagliptin. Higher levels of proteinuria in Nx rats compared to control rats were accompanied by higher urinary excretion of retinol-binding protein 4, a marker of tubular proteinuria, as well as higher urinary levels of podocin, a marker of glomerular proteinuria. Retinol-binding protein 4 and podocin were not detected in the urine of Nx + DPP4i rats. Tubular and glomerular proteinuria was associated with the reduced expression of megalin and podocin in the renal cortex of Nx rats. Sitagliptin treatment partially prevented this decrease. Besides, the angiotensin II renal content was significantly reduced in the Nx rats that received sitagliptin compared to vehicle-treated Nx rats. Interestingly, both urinary DPP4 activity and abundance increased progressively in Nx rats. Additionally, urinary DPP4 activity correlated positively with serum creatinine levels, proteinuria, and blood pressure. Collectively, these results suggest that DPP4 inhibition ameliorated both tubular and glomerular proteinuria and prevented the reduction of megalin and podocin expression in CKD rats. Furthermore, these findings suggest that urinary DPP4 activity may serve as a biomarker of renal disease and progression.
Assuntos
Dipeptidil Peptidase 4/urina , Inibidores da Dipeptidil Peptidase IV/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Rim/efeitos dos fármacos , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Proteínas de Membrana/metabolismo , Proteinúria/prevenção & controle , Insuficiência Renal Crônica/prevenção & controle , Fosfato de Sitagliptina/farmacologia , Angiotensina II/metabolismo , Animais , Biomarcadores/urina , Modelos Animais de Doenças , Fibrose , Rim/enzimologia , Rim/patologia , Masculino , Proteinúria/enzimologia , Proteinúria/patologia , Proteinúria/urina , Ratos Wistar , Insuficiência Renal Crônica/enzimologia , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/urina , Proteínas Plasmáticas de Ligação ao Retinol/urina , Transdução de SinaisRESUMO
It has been shown that cyclooxygenase (COX)-2-dependent activation of renal (pro)renin receptor (PRR) contributes to angiotensin II (ANG II)-induced hypertension. However, less is known about the involvement of this mechanism in ANG II-independent hypertension. The goal of the present study was to test whether or not COX-2-dependent upregulation of PRR serves as a universal mechanism contributing to ANG II-dependent and -independent hypertension. Here, we examined the association between renal COX-2 and PRR during deoxycorticosterone acetate (DOCA)-salt hypertension in rats. By immunoblot analysis and immunofluorescence, renal protein expression of PRR was remarkably upregulated by DOCA-salt treatment. Surprisingly, this upregulation of renal PRR expression was unaffected by a COX-2 inhibitor, celecoxib. To address the role of renal PRR to the pathogenesis of DOCA-salt hypertension, a decoy PRR inhibitor, PRO20, was infused to the renal medulla of uninephrectomized Sprague-Dawley rats for 14 days. Radiotelemetry demonstrated effective attenuation of DOCA-salt hypertension by intramedullary infusion of a PRR inhibitor, PRO20. In parallel, DOCA-salt-induced hypertrophy in the heart and kidney as well as proteinuria were improved, accompanied with blunted polydipsia and polyuria. In contrast, intravenous infusion of PRO20 was less effective in attenuating DOCA-salt hypertension and cardiorenal injury. Together, these results suggest that COX-2-independent activation of renal PRR contributes to DOCA-salt hypertension.
Assuntos
Pressão Sanguínea , Ciclo-Oxigenase 2/metabolismo , Acetato de Desoxicorticosterona , Hipertensão/enzimologia , Rim/enzimologia , Receptores de Superfície Celular/metabolismo , Cloreto de Sódio na Dieta , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/enzimologia , Cardiomegalia/fisiopatologia , Modelos Animais de Doenças , Ativação Enzimática , Hipertensão/induzido quimicamente , Hipertensão/fisiopatologia , Rim/fisiopatologia , Masculino , Proteinúria/induzido quimicamente , Proteinúria/enzimologia , Proteinúria/fisiopatologia , Ratos Sprague-Dawley , Transdução de Sinais , ATPases Vacuolares Próton-TranslocadorasRESUMO
BACKGROUND: Vorolanib (X-82, CM082) is a multi-target tyrosine kinase inhibitor. This study aimed to evaluate the tolerability, safety, pharmacokinetics and antitumor activities of vorolanib plus everolimus (an inhibitor of mammalian target of rapamycin). METHODS: Patients had histologically or cytologically confirmed advanced RCC and failed with standard therapy were eligible for this study. Dose-escalated combinations of vorolanib (100, 150 or 200 mg once daily) with everolimus (5 mg once daily) were administered on 28-day cycles until disease progression or unacceptable toxicity using a conventional 3 + 3 dose-escalation design. FINDINGS: 22 patients (100 mg n = 4, 150 mg n = 3, 200 mg n = 15) were enrolled. Only one patient experienced dose-limiting toxicity (DLT, grade 4 thrombocytopenia) in the vorolanib 200 mg combination cohort, and the maximum tolerated dose (MTD) was not reached. The most common treatment-related adverse events were proteinuria (100%), leukopenia (77%), hypercholesterolaemia (77%), increased low-density lipoprotein (68%), hypertriglyceridaemia (64%), hyperglycaemia (59%), and fatigue (55%). Most treatment-related adverse events were grade 1 to 2, with grade 3 or higher toxicities mostly seen in the 200 mg cohort. Single dosing of vorolanib demonstrated dose-proportional increases in the Cmax and AUC, and observed short t1/2z ranging from 4.74±1.44 to 12.89±7.49 h. The pharmacokinetic parameters for everolimus were similar among all cohorts. Of 19 evaluable patients, the ORR and DCR was 32% (n = 6, 95% CI, 13-57%) and 100% (95% CI, 82-100%), respectively. INTERPRETATION: Combination therapy of vorolanib 200 mg plus everolimus 5 mg once daily is potentially effective with potential activity. Further evaluation of the combination in advanced RCC patients is ongoing (NCT03095040). FUNDING: Betta Pharmaceutical Co., Ltd., Hangzhou, China.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Renais/tratamento farmacológico , Everolimo/administração & dosagem , Indóis/administração & dosagem , Neoplasias Renais/tratamento farmacológico , Inibidores de Proteínas Quinases/administração & dosagem , Pirróis/administração & dosagem , Pirrolidinas/administração & dosagem , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Renais/enzimologia , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Progressão da Doença , Esquema de Medicação , Everolimo/efeitos adversos , Feminino , Humanos , Hipercolesterolemia/enzimologia , Hipercolesterolemia/etiologia , Hipercolesterolemia/mortalidade , Hiperglicemia/enzimologia , Hiperglicemia/etiologia , Hiperglicemia/mortalidade , Indóis/efeitos adversos , Neoplasias Renais/enzimologia , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Leucopenia/enzimologia , Leucopenia/etiologia , Leucopenia/mortalidade , Masculino , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/efeitos adversos , Proteinúria/enzimologia , Proteinúria/etiologia , Proteinúria/mortalidade , Pirróis/efeitos adversos , Pirrolidinas/efeitos adversos , Análise de SobrevidaRESUMO
Tobacco smoking has been identified as a risk factor in the progression of chronic kidney disease (CKD). In previous studies, we showed that nicotine induces cyclooxygenase (COX)-2 expression in vivo and in vitro and that the administration of nicotine in vivo worsens the severity of renal injury in a model of subtotal renal ablation. In the present study, we tested the role of COX-2-derived prostaglandins on the deleterious effects of nicotine in CKD. Sham and 5/6 nephrectomy (5/6Nx) rats received tap water or nicotine (100 µg/mL) in the drinking water for 12 wk. Additional groups also systemically received the COX-2 inhibitor NS-398 (1.5 mg·kg-1·day-1 via osmotic minipump). The administration of nicotine worsened renal injury and proteinuria in 5/6Nx rats and increased proteinuria in sham rats. 5/6Nx rats had increased cortical production of the prostaglandins PGE2, PGI2, PGD2, and PGF2α and of thromboxane A2. In these rats, nicotine reduced the production of all prostaglandins examined except thromboxane A2. Treatment with the COX-2 inhibitor NS-398 resulted in complete inhibition of all prostaglandins studied and ameliorated renal injury and proteinuria in 5/6Nx rats on nicotine but not in 5/6 Nx rats on tap water. Nicotine also reduced the expression of megalin in all groups examined, and this was partially prevented by COX-2 inhibition. In the present study, we showed that in CKD, nicotine worsens renal injury at least in part by producing an imbalance in the production of prostaglandins. This imbalance in the production of prostaglandins likely plays a role in the deleterious effects of smoking on the progression of CKD.
Assuntos
Ciclo-Oxigenase 2/metabolismo , Rim/efeitos dos fármacos , Nicotina/toxicidade , Agonistas Nicotínicos/toxicidade , Prostaglandinas/metabolismo , Insuficiência Renal Crônica/induzido quimicamente , Animais , Inibidores de Ciclo-Oxigenase 2/farmacologia , Dinoprosta/metabolismo , Dinoprostona/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Epoprostenol/metabolismo , Rim/enzimologia , Rim/patologia , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Masculino , Nefrectomia , Prostaglandina D2/metabolismo , Proteinúria/induzido quimicamente , Proteinúria/enzimologia , Ratos Sprague-Dawley , Insuficiência Renal Crônica/enzimologia , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/prevenção & controle , Transdução de Sinais , Tromboxano A2/metabolismoRESUMO
Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). The ROS-mediated PI3K/AKT pathway plays a key role in podocyte apoptosis and DN progression. Our previous study demonstrated that Baoshenfang (BSF) can decrease proteinuria and attenuate podocyte injury. However, the effects of BSF on podocyte apoptosis induced by the ROS-mediated PI3K/AKT pathway remain unclear. Herein, in vivo and in vitro studies have been performed. In our in vivo study, BSF significantly decreased 24-h urinary protein, serum creatinine, and blood urea nitrogen levels in DN mice. Meanwhile, BSF significantly inhibited oxidative stress and podocyte apoptosis in our in vivo and in vitro studies. Moreover, BSF significantly decreased the inhibition of the PI3K/AKT pathway induced by HG in DN. More importantly, the effects of BSF on podocyte apoptosis were reversed by PI3K siRNA transfection. In conclusion, BSF can decrease proteinuria and podocyte apoptosis in DN, in part through regulating the ROS-mediated PI3K/AKT pathway.
Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Nefropatias Diabéticas/tratamento farmacológico , Medicamentos de Ervas Chinesas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Podócitos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular , Nefropatias Diabéticas/enzimologia , Nefropatias Diabéticas/patologia , Modelos Animais de Doenças , Glucose/toxicidade , Masculino , Camundongos Endogâmicos C57BL , NADPH Oxidase 4/genética , NADPH Oxidase 4/metabolismo , Fosfatidilinositol 3-Quinase/genética , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Podócitos/enzimologia , Podócitos/patologia , Proteinúria/enzimologia , Proteinúria/patologia , Proteinúria/prevenção & controle , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
BACKGROUND: Protein phosphorylation & dephosphorylation are ubiquitous cellular processes that allow for the nuanced and reversible regulation of protein activity. Protein phosphatase 2A (PP2A) is a multifunction phosphatase that is well expressed in all cell types of kidney during early renal development, though its functions in kidney remains to be elucidated. METHODS: PP2A conditional knock-out mice was generated with PP2A fl/fl mice that were crossed with Podocin-Cre mice. The phenotype of Pod-PP2A-KO mice (homozygous for the floxed PP2A allele with Podocin-Cre) and littermate PP2A fl/fl controls (homozygous for the PP2A allele but lacking Podocin-Cre) were further studied. Primary podocytes isolated from the Pod-PP2A-KO mice were cultured and they were then employed with sing label-free nano-LC - MS/MS technology on a Q-exactive followed by SIEVE processing to identify possible target molecular entities for the dephosphorylation effect of PP2A, in which Western blot and immunofluorescent staining were used to analyze further. RESULTS: Pod-PP2A-KO mice were developed with weight loss, growth retardation, proteinuria, glomerulopathy and foot process effacement, together with reduced expression of some slit diaphragm molecules and cytoskeleton rearrangement of podocytes. Y box protein 1 (YB-1) was identified to be the target molecule for dephosphorylation effect of PP2A. Furthermore, YB-1 phosphorylation was up-regulated in the Pod-PP2A-KO mice in contrast to the wild type controls, while total and un-phosphorylated YB-1 both was moderately down-regulated in podocytes from the Pod-PP2A-KO mice. CONCLUSION: Our study revealed the important role of PP2A in regulating the development of foot processes and fully differentiated podocytes whereas fine-tuning of YB-1 via a post-translational modification by PP2A regulating its activity might be crucial for the functional integrity of podocytes and glomerular filtration barrier.
Assuntos
Glomérulos Renais/citologia , Glomérulos Renais/fisiologia , Podócitos/citologia , Proteína Fosfatase 2/metabolismo , Animais , Peso Corporal , Citoesqueleto/metabolismo , Feminino , Regulação Enzimológica da Expressão Gênica , Técnicas de Inativação de Genes , Humanos , Glomérulos Renais/patologia , Glomérulos Renais/fisiopatologia , Masculino , Camundongos , Fosforilação , Podócitos/patologia , Proteína Fosfatase 2/deficiência , Proteína Fosfatase 2/genética , Proteinúria/enzimologia , Proteinúria/genética , Proteína 1 de Ligação a Y-Box/metabolismoRESUMO
BACKGROUND: Previously we found that kidney tissue and urinary exosomes from patients of diabetic kidney disease showed high levels of ceruloplasmin (CP). Because CP is an acute-phase protein of kidney origin, it could be an early marker of many other kidney diseases. To investigate this hypothesis, we first measured urine exosomal and kidney expression of CP in non-diabetic chronic kidney disease (CKD) patients (membranous nephropathy, focal segmental glomerulosclerosis, lupus nephritis and IgA nephropathy) followed by a longitudinal study in rat passive Heymann nephritis (PHN), a model of human membranous nephropathy. METHODS: Urinary exosomes were isolated from urine of patients (and rats) by differential centrifugation. The exosomal extracts were used for measuring CP using ELISA. Kidney expression of CP was evaluated by immune-staining biopsy tissues. Similar techniques were applied in rat PHN model (produced by injection of anti-gp600 antiserum) to analyze urine exosomal and kidney CP. RESULTS: Urine exosomal CP levels were 10-20 times higher in CKD patients than in controls; consistent with this we found high immune-reactive CP localized in tubules and collecting ducts of biopsies of CKD patients. In the PHN model urinary exosomal CP level was significantly higher prior to the onset of proteinuria. Early rise of urine exosomal CP, which preceded proteinuria, correlated with high immunoreactive CP found in rat kidneys at this time. CONCLUSION: We propose that urine exosomal CP, observed to increase prior to proteinuria, makes it a potential urinary biomarker to diagnose early kidney disease.
Assuntos
Ceruloplasmina/urina , Exossomos/enzimologia , Glomerulonefrite Membranosa/urina , Rim/enzimologia , Proteinúria/urina , Insuficiência Renal Crônica/urina , Adulto , Animais , Biomarcadores/urina , Estudos de Casos e Controles , Modelos Animais de Doenças , Diagnóstico Precoce , Exossomos/patologia , Feminino , Glomerulonefrite Membranosa/diagnóstico , Glomerulonefrite Membranosa/enzimologia , Humanos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Proteinúria/diagnóstico , Proteinúria/enzimologia , Ratos Sprague-Dawley , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/enzimologia , Regulação para CimaRESUMO
We identified 2 genes, histone deacetylase 1 (HDAC1) and HDAC2, contributing to the pathogenesis of proteinuric kidney diseases, the leading cause of end-stage kidney disease. mRNA expression profiling from proteinuric mouse glomeruli was linked to Connectivity Map databases, identifying HDAC1 and HDAC2 with the differentially expressed gene set reversible by HDAC inhibitors. In numerous progressive glomerular disease models, treatment with valproic acid (a class I HDAC inhibitor) or SAHA (a pan-HDAC inhibitor) mitigated the degree of proteinuria and glomerulosclerosis, leading to a striking increase in survival. Podocyte HDAC1 and HDAC2 activities were increased in mice podocytopathy models, and podocyte-associated Hdac1 and Hdac2 genetic ablation improved proteinuria and glomerulosclerosis. Podocyte early growth response 1 (EGR1) was increased in proteinuric patients and mice in an HDAC1- and HDAC2-dependent manner. Loss of EGR1 in mice reduced proteinuria and glomerulosclerosis. Longitudinal analysis of the multicenter Veterans Aging Cohort Study demonstrated a 30% reduction in mean annual loss of estimated glomerular filtration rate, and this effect was more pronounced in proteinuric patients receiving valproic acid. These results strongly suggest that inhibition of HDAC1 and HDAC2 activities may suppress the progression of human proteinuric kidney diseases through the regulation of EGR1.
Assuntos
Glomerulosclerose Segmentar e Focal , Histona Desacetilase 1 , Histona Desacetilase 2 , Inibidores de Histona Desacetilases/farmacologia , Podócitos , Animais , Linhagem Celular Tumoral , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Feminino , Glomerulosclerose Segmentar e Focal/enzimologia , Glomerulosclerose Segmentar e Focal/genética , Glomerulosclerose Segmentar e Focal/patologia , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 1/genética , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/antagonistas & inibidores , Histona Desacetilase 2/genética , Histona Desacetilase 2/metabolismo , Humanos , Masculino , Camundongos Knockout , Podócitos/enzimologia , Podócitos/patologia , Proteinúria/tratamento farmacológico , Proteinúria/enzimologia , Proteinúria/genética , Proteinúria/patologiaRESUMO
Podocyte malfunction occurs in autoimmune and nonautoimmune kidney disease. Calcium signaling is essential for podocyte injury, but the role of Ca2+/calmodulin-dependent kinase (CaMK) signaling in podocytes has not been fully explored. We report that podocytes from patients with lupus nephritis and focal segmental glomerulosclerosis and lupus-prone and lipopolysaccharide- or adriamycin-treated mice display increased expression of CaMK IV (CaMK4), but not CaMK2. Mechanistically, CaMK4 modulated podocyte motility by altering the expression of the GTPases Rac1 and RhoA and suppressed the expression of nephrin, synaptopodin, and actin fibers in podocytes. In addition, it phosphorylated the scaffold protein 14-3-3ß, which resulted in the release and degradation of synaptopodin. Targeted delivery of a CaMK4 inhibitor to podocytes preserved their ultrastructure, averted immune complex deposition and crescent formation, and suppressed proteinuria in lupus-prone mice and proteinuria in mice exposed to lipopolysaccharide-induced podocyte injury by preserving nephrin/synaptopodin expression. In animals exposed to adriamycin, podocyte-specific delivery of a CaMK4 inhibitor prevented and reversed podocyte injury and renal disease. We conclude that CaMK4 is pivotal in immune and nonimmune podocyte injury and that its targeted cell-specific inhibition preserves podocyte structure and function and should have therapeutic value in lupus nephritis and podocytopathies, including focal segmental glomerulosclerosis.
Assuntos
Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/metabolismo , Glomerulosclerose Segmentar e Focal/enzimologia , Glomérulos Renais/enzimologia , Nefrite Lúpica/enzimologia , Transdução de Sinais , Animais , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/imunologia , Linhagem Celular Transformada , Feminino , Glomerulosclerose Segmentar e Focal/imunologia , Glomerulosclerose Segmentar e Focal/patologia , Humanos , Glomérulos Renais/imunologia , Glomérulos Renais/patologia , Nefrite Lúpica/imunologia , Nefrite Lúpica/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos MRL lpr , Camundongos Knockout , Proteinúria/enzimologia , Proteinúria/imunologia , Proteinúria/patologiaRESUMO
The aim of our current study was to investigate the long-term effect and the mechanism of triptolide in an adult nonorthologous rat model of polycystic kidney disease (PKD). Male wild-type (+/+) and Cy/+ cystic Han:SPRD rats were treated with vehicle or triptolide from 4 to 16 wk of age. Rats were killed at 16 wk of age for blood, urine, and organ collection. Human-derived WT9-12 PKD cells were treated with triptolide with or without IL-6 pretreatment. Cell proliferation, apoptosis, and cytotoxicity were determined. Western blotting and immunohistochemistry analysis were performed to evaluate the activation of IL-6-JAK2-STAT3 pathway. Renal function was protected by 12 wk of triptolide treatment in cystic Han:SPRD rats as shown by reduced blood urea nitrogen, serum creatinine, and proteinuria levels. Cyst and kidney growth were also retarded by triptolide treatment in Cy/+ rats. We further found that the proliferation index was reduced by triptolide in cystic rats, which was correlated with the reduced expression of IL-6/IL-6 receptor, decreased phosphorylation of JAK2-STAT3, and increased expression of suppressor of cytokine signaling 3 (SOCS3). The inhibitory effect of triptolide was further studied in WT9-12 cells. Triptolide inhibited cell proliferation and the activation of JAK2-STAT3 pathway in PKD cells, but it increased the expression of SOCS3. Pretreatment with IL-6 attenuated the inhibitory effect of triptolide on STAT3 phosphorylation. Our study revealed a long-term beneficial effect of triptolide in PKD that was probably through inhibition of the JAK2-STAT3 pathway.
Assuntos
Diterpenos/farmacologia , Janus Quinase 2/metabolismo , Rim/efeitos dos fármacos , Fenantrenos/farmacologia , Doenças Renais Policísticas/prevenção & controle , Fator de Transcrição STAT3/metabolismo , Animais , Apoptose/efeitos dos fármacos , Nitrogênio da Ureia Sanguínea , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Creatinina/sangue , Modelos Animais de Doenças , Progressão da Doença , Compostos de Epóxi/farmacologia , Humanos , Interleucina-6/metabolismo , Rim/enzimologia , Rim/patologia , Rim/fisiopatologia , Masculino , Fosforilação , Doenças Renais Policísticas/enzimologia , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/patologia , Proteinúria/enzimologia , Proteinúria/genética , Proteinúria/prevenção & controle , Ratos Transgênicos , Receptores de Interleucina-6/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína 3 Supressora da Sinalização de Citocinas/metabolismoRESUMO
It is well known that proteinuria following urinary tract obstruction is mainly of a tubular nature. However, it is unknown whether there are also changes in glomerular permeability. In this study, we compared glomerular sieving coefficients (θ) of polydisperse fluorescein isothiocyanate (FITC)-Ficoll 70/400 following a 120- or 180-min unilateral ureteral obstruction (UUO) in anesthetized Sprague-Dawley rats. Samples were collected from the obstructed kidney at 5, 15, and 30 min postrelease and analyzed by means of high-pressure size-exclusion chromatography. After 120-min UUO, mean θ for Ficoll70Å was increased ( P < 0.01) from 2.2 ± 0.5 × 10-5 (baseline) to 10.6 ± 10 × 10-5 15 min postrelease (highest value). After 180-min UUO, mean θ for Ficoll70Å was further increased ( P < 0.001) from 1.4 ± 0.5 × 10-5 (baseline) to 40 ± 10 × 10-5 at 5 min postrelease (highest value). Administration of a reactive oxygen species (ROS) scavenger (Tempol; 1 mg·kg-1·min-1) partly abrogated the permeability effects following 120-min UUO but not after 180 min. Moreover, administration of the RhoA kinase inhibitor Y-27632, the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester, or Rac-1 inhibition did not ameliorate glomerular hyperpermeability following 180-min UUO. We show, for the first time, that acute UUO results in marked elevations in glomerular permeability. In addition, our data suggest a time-dependent pathophysiology of UUO-induced hyperpermeability, where reactive oxygen species generation may play an important role in the early stages.
Assuntos
Antioxidantes/farmacologia , Óxidos N-Cíclicos/farmacologia , Inibidores Enzimáticos/farmacologia , Taxa de Filtração Glomerular/efeitos dos fármacos , Glomérulos Renais/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Estresse Oxidativo/efeitos dos fármacos , Obstrução Ureteral/tratamento farmacológico , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores , Proteínas rho de Ligação ao GTP/antagonistas & inibidores , Amidas/farmacologia , Aminoquinolinas/farmacologia , Animais , Pressão Arterial/efeitos dos fármacos , Modelos Animais de Doenças , Frequência Cardíaca/efeitos dos fármacos , Glomérulos Renais/enzimologia , Glomérulos Renais/fisiopatologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Proteinúria/tratamento farmacológico , Proteinúria/enzimologia , Proteinúria/fisiopatologia , Piridinas/farmacologia , Pirimidinas/farmacologia , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Marcadores de Spin , Fatores de Tempo , Obstrução Ureteral/enzimologia , Obstrução Ureteral/fisiopatologia , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Quinases Associadas a rho/antagonistas & inibidores , Quinases Associadas a rho/metabolismoRESUMO
The Notch pathway has been reported to control tissue damage in acute kidney diseases. To investigate potential beneficial nephroprotective effects of targeting Notch, we developed chemically functionalized γ-secretase inhibitors (GSIs) targeting γ-glutamyltranspeptidase (γ-GT) and/or γ-glutamylcyclotransferase (γ-GCT), two enzymes overexpressed in the injured kidney, and evaluated them in in vivo murine models of acute tubular and glomerular damage. Exposure of the animals to disease-inducing drugs together with the functionalized GSIs improved proteinuria and, to some extent, kidney dysfunction. The expression of genes involved in the Notch pathway, acute inflammatory stress responses, and the renin-angiotensin system was enhanced in injured kidneys, which could be downregulated upon administration of functionalized GSIs. Immunohistochemistry staining and Western blots demonstrated enhanced activation of Notch1 as detected by its cleaved active intracellular domain during acute kidney injury, and this was downregulated by concomitant treatment with the functionalized GSIs. Thus targeted γ-secretase-based prodrugs developed as substrates for γ-GT/γ-GCT have the potential to selectively control Notch activation in kidney diseases with subsequent regulation of the inflammatory stress response and the renin-angiotensin pathways.
Assuntos
Injúria Renal Aguda/prevenção & controle , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Rim/efeitos dos fármacos , Receptor Notch1/metabolismo , gama-Glutamilciclotransferase/antagonistas & inibidores , gama-Glutamiltransferase/antagonistas & inibidores , Injúria Renal Aguda/enzimologia , Injúria Renal Aguda/genética , Injúria Renal Aguda/patologia , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Citoproteção , Modelos Animais de Doenças , Rim/enzimologia , Rim/patologia , Masculino , Camundongos Endogâmicos BALB C , Proteinúria/enzimologia , Proteinúria/patologia , Proteinúria/prevenção & controle , Receptor Notch1/genética , Transdução de Sinais/efeitos dos fármacos , gama-Glutamilciclotransferase/genética , gama-Glutamilciclotransferase/metabolismo , gama-Glutamiltransferase/genética , gama-Glutamiltransferase/metabolismoRESUMO
Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a major deubiquitinating enzyme of the nervous system and associated with the development of neurodegenerative diseases. We have previously shown that UCH-L1 is found in tubular and parietal cells of the kidney and is expressed de novo in injured podocytes. Since the role of UCH-L1 in the kidney is unknown we generated mice with a constitutive UCH-L1-deficiency to determine its role in renal health and disease. UCH-L1-deficient mice developed proteinuria, without gross changes in glomerular morphology. Tubular cells, endothelial cells, and podocytes showed signs of stress with an accumulation of oxidative-modified and polyubiquitinated proteins. Mechanistically, abnormal protein accumulation resulted from an altered proteasome abundance leading to decreased proteasomal activity, a finding exaggerated after induction of anti-podocyte nephritis. UCH-L1-deficient mice exhibited an exacerbated course of disease with increased tubulointerstitial and glomerular damage, acute renal failure, and death, the latter most likely a result of general neurologic impairment. Thus, UCH-L1 is required for regulated protein degradation in the kidney by controlling proteasome abundance. Altered proteasome abundance renders renal cells, particularly podocytes and endothelial cells, susceptible to injury.
Assuntos
Glomerulonefrite/enzimologia , Doenças do Complexo Imune/enzimologia , Podócitos/enzimologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina Tiolesterase/metabolismo , Ubiquitina/metabolismo , Animais , Células Cultivadas , Modelos Animais de Doenças , Glomerulonefrite/genética , Glomerulonefrite/imunologia , Glomerulonefrite/patologia , Hipotensão/enzimologia , Hipotensão/genética , Doenças do Complexo Imune/genética , Doenças do Complexo Imune/imunologia , Doenças do Complexo Imune/patologia , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos Knockout , Oxirredução , Podócitos/imunologia , Podócitos/patologia , Proteinúria/enzimologia , Proteinúria/genética , Proteólise , Ubiquitina Tiolesterase/deficiência , Ubiquitina Tiolesterase/genética , UbiquitinaçãoRESUMO
AIM: Matrix metalloproteinase-12 (MMP-12; macrophage elastase) is an enzyme that can cleave various extracellular matrix proteins and is required for macrophage infiltration and pulmonary fibrosis in experimental emphysema. We have shown previously that MMP-12 is highly up-regulated in experimental anti-glomerular basement membrane (GBM) disease. The aim of this study was to determine whether MMP-12 is required for glomerular macrophage infiltration and crescent formation in anti-GBM glomerulonephritis. METHODS: Accelerated anti-GBM disease was induced in groups of MMP-12 gene deficient mice (MMP-12-/-) and wild-type C57BL/6J controls, which were killed 12 days after injection of anti-GBM serum. RESULTS: Wild-type and MMP-12-/- mice developed glomerular damage and glomerular tuft adhesions to Bowman's capsule. Both groups developed severe proteinuria. Wild-type mice also developed significant loss of renal function and crescents in 22% of glomeruli, which were associated with macrophage infiltration and Bowman's capsule rupture. In contrast, MMP-12-/- mice were partially protected from renal function decline, crescent formation and Bowman's capsule rupture. This was associated with reduced macrophage infiltration in both glomeruli and the interstitium, and with reduced expression of CCL2, TNF-α and iNOS mRNA in MMP-12-/- kidneys. In addition, KIM-1 mRNA levels were reduced in MMP-12-/- mice indicating less tubular damage. CONCLUSION: These data demonstrate that endogenous MMP-12 facilitates macrophage accumulation and activation in anti-GBM glomerulonephritis which is required for glomerular crescent formation, Bowman's capsule rupture, tubular damage and renal function decline.
Assuntos
Doença Antimembrana Basal Glomerular/prevenção & controle , Glomérulos Renais/enzimologia , Macrófagos/enzimologia , Metaloproteinase 12 da Matriz/deficiência , Animais , Doença Antimembrana Basal Glomerular/enzimologia , Doença Antimembrana Basal Glomerular/genética , Doença Antimembrana Basal Glomerular/patologia , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Modelos Animais de Doenças , Feminino , Predisposição Genética para Doença , Receptor Celular 1 do Vírus da Hepatite A/genética , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Mediadores da Inflamação/metabolismo , Glomérulos Renais/patologia , Glomérulos Renais/fisiopatologia , Macrófagos/patologia , Metaloproteinase 12 da Matriz/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fenótipo , Proteinúria/enzimologia , Proteinúria/genética , Proteinúria/prevenção & controle , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Nie X, Chanley MA, Pengal R, Thomas DB, Agrawal S, Smoyer WE. Pharmacological and genetic inhibition of downstream targets of p38 MAPK in experimental nephrotic syndrome. Am J Physiol Renal Physiol 314: F602-F613, 2018. First published November 29, 2017; doi: 10.1152/ajprenal.00207.2017 .-The p38 MAPK pathway plays a crucial role in various glomerulopathies, with activation being associated with disease and inhibition being associated with disease amelioration. We hypothesized that the downstream targets of p38 MAPK, MAPK-activated protein kinase 2 and/or 3 (MK2 and/or MK3), play an important role in mediating injury in experimental nephrotic syndrome via their actions on their downstream substrates heat shock protein B1 (HSPB1) and cyclooxygenase-2 (COX-2). To test this hypothesis, the effects of both pharmacological and genetic inhibition of MK2 and MK3 were examined in mouse adriamycin (ADR) and rat puromycin aminonucleoside (PAN) nephropathy models. MK2-/-, MK3-/-, and MK2-/-MK3-/- mice were generated in the Sv129 background and subjected to ADR-induced nephropathy. MK2 and MK3 protein expression was completely abrogated in the respective knockout genotypes, and massive proteinuria and renal histopathological changes developed after ADR treatment. Furthermore, renal cortical HSPB1 was induced in all four genotypes by day 21, but HSPB1 was activated only in the wild-type and MK3-/- mice. Expression of the stress proteins HSPB8 and glucose-regulated protein 78 (GRP78) remained unaltered across all genotypes. Finally, while MK2 and/or MK3-knockout downregulated the proinflammatory enzyme COX-2, ADR significantly induced renal cortical COX-2 only in MK2-/- mice. Additionally, pharmacological MK2 inhibition with PF-318 during PAN-induced nephropathy did not result in significant proteinuria reduction in rats. Together, these data suggest that while the inhibition of MK2 and/or MK3 regulates the renal stress response, our currently available approaches are not yet able to safely and effectively reduce proteinuria in experimental nephrotic syndrome and that other p38MAPK downstream targets should also be considered to improve the future treatment of glomerular disease.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/genética , Rim/efeitos dos fármacos , Síndrome Nefrótica/prevenção & controle , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteinúria/prevenção & controle , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Ciclo-Oxigenase 2/metabolismo , Modelos Animais de Doenças , Doxorrubicina , Chaperona BiP do Retículo Endoplasmático , Técnicas de Inativação de Genes , Proteínas de Choque Térmico/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Rim/enzimologia , Masculino , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Chaperonas Moleculares , Proteínas de Neoplasias/metabolismo , Síndrome Nefrótica/enzimologia , Síndrome Nefrótica/genética , Inibidores de Proteínas Quinases/toxicidade , Proteínas Serina-Treonina Quinases/metabolismo , Proteinúria/enzimologia , Proteinúria/genética , Puromicina Aminonucleosídeo , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
Podocytes play an important role in maintaining glomerular function, and podocyte injury is a significant component in the pathogenesis of proteinuria. Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose genetic deficiency and pharmacological inhibition have beneficial effects on renal function, but its role in podocytes remains unexplored. The objective of this study was to investigate the contribution of sEH in podocytes to lipopolysaccharide (LPS)-induced kidney injury. We report increased sEH transcript and protein expression in murine podocytes upon LPS challenge. To determine the function of sEH in podocytes in vivo we generated podocyte-specific sEH-deficient (pod-sEHKO) mice. Following LPS challenge, podocyte sEH-deficient mice exhibited lower kidney injury, proteinuria, and blood urea nitrogen concentrations than controls suggestive of preserved renal function. Also, renal mRNA and serum concentrations of inflammatory cytokines IL-6, IL-1ß, and TNFα were significantly lower in LPS-treated pod-sEHKO than control mice. Moreover, podocyte sEH deficiency was associated with decreased LPS-induced NF-κB and MAPK activation and attenuated endoplasmic reticulum stress. Furthermore, the protective effects of podocyte sEH deficiency in vivo were recapitulated in E11 murine podocytes treated with a selective sEH pharmacological inhibitor. Altogether, these findings identify sEH in podocytes as a contributor to signaling events in acute renal injury and suggest that sEH inhibition may be of therapeutic value in proteinuria. ENZYMES: Soluble epoxide hydrolase: EC 3.3.2.10.
Assuntos
Injúria Renal Aguda/enzimologia , Epóxido Hidrolases/deficiência , Podócitos/enzimologia , Proteinúria/enzimologia , Injúria Renal Aguda/genética , Animais , Nitrogênio da Ureia Sanguínea , Células Cultivadas , Citocinas/sangue , Citocinas/genética , Citocinas/metabolismo , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Immunoblotting , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Lipopolissacarídeos/farmacologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia de Fluorescência , Compostos de Fenilureia/farmacologia , Piperidinas/farmacologia , Proteinúria/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , SolubilidadeRESUMO
Mammalian target for rapamycin complex 1 (mTORC1) is a common target for the action of immunosuppressant macrolide rapamycin and glucose-lowering metformin. Inhibition of mTORC1 can exert both beneficial and detrimental effects in different pathologies. Here, we investigated the differential effects of rapamycin (1.2 mg/kg per day delivered subcutaneously for 6 weeks) and metformin (300 mg/kg per day delivered orally for 11 weeks) treatments on male Zucker diabetic fatty (ZDF) rats that mimic the cardiorenal pathology of type 2 diabetic patients and progress to insulin insufficiency. Rapamycin and metformin improved proteinuria, and rapamycin also reduced urinary gamma glutamyl transferase (GGT) indicating improvement of tubular health. Metformin reduced food and water intake, and urinary sodium and potassium, whereas rapamycin increased urinary sodium. Metformin reduced plasma alkaline phosphatase, but induced transaminitis as evidenced by significant increases in plasma AST and ALT. Metformin also induced hyperinsulinemia, but did not suppress fasting plasma glucose after ZDF rats reached 17 weeks of age, and worsened lipid profile. Rapamycin also induced mild transaminitis. Additionally, both rapamycin and metformin increased plasma uric acid and creatinine, biomarkers for cardiovascular and renal disease. These observations define how rapamycin and metformin differentially modulate metabolic profiles that regulate cardiorenal pathology in conditions of severe type 2 diabetes.
Assuntos
Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Resistência à Insulina , Metformina/farmacologia , Complexos Multiproteicos/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Biomarcadores/sangue , Biomarcadores/urina , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/enzimologia , Doenças Cardiovasculares/etiologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/enzimologia , Nefropatias Diabéticas/enzimologia , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/prevenção & controle , Modelos Animais de Doenças , Progressão da Doença , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/metabolismo , Proteinúria/enzimologia , Proteinúria/etiologia , Proteinúria/prevenção & controle , Ratos Zucker , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Fatores de TempoRESUMO
Shenkangling plays a role of Yishenhuoxue effect for the treatment of children with nephrotic syndrome. The aim of this study was to investigate the effects of Shenkangling intervention on the mitogen-activated protein kinase (MAPK) pathway in rats with Adriamycin-induced nephropathy (AN) and its underlying mechanism of action. Nephrosis was induced in healthy Sprague-Dawley rats by doxorubicin and the rats were untreated or treated with prednisone, simvastatin, Shenkangling, or a combination thereof. Using real-time PCR, the mRNA expression levels of Chemokine (C-X-C motif) ligand 16 (CXCL16), A Disintegrin and metalloproteinase domain-containing protein 10 (ADAM10), and ADAM17 in the renal tissues of these rats were found to be decreased by the various treatments compared to those in the untreated doxorubicin-induced nephrosis rats. To quantify the activation of the MAPK pathway, western blotting was used to detect the phosphorylation levels of MAPK pathway-associated proteins (p38, ERK1/2, SAPK/JNK) and nuclear factor (NF)-κB p65, which were reduced by the various treatments compared to those in the untreated doxorubicin-induced rats. Serum levels of transforming growth factor (TGF)-ß1, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6, quantified by ELISA, were decreased by the various treatments compared to the levels in the untreated doxorubicin-induced nephrosis rats. The rats treated with prednisone, simvastatin, and Shenkangling showed the best outcome. The Chinese medicine Shenkangling that is known for nourishing the kidney and promoting blood circulation reduced urinary protein levels, increased serum albumin levels, and reduced cholesterol levels by reducing the release of CXCL16, ADAM10, ADAM17, TGF-ß1, TNF-α, IL-1ß, IL- 6, and other inflammatory mediators and inhibiting the activation of the MAPK signaling pathway, thereby effectively improving the state of nephropathy in AN rats. These results indicate that Shenkangling can be used clinically to treat nephropathy.
Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Síndrome Nefrótica/tratamento farmacológico , Proteína ADAM10/genética , Proteína ADAM17/genética , Animais , Quimiocina CXCL6/genética , Doxorrubicina/toxicidade , Interleucina-1beta/sangue , Interleucina-6/sangue , Masculino , NF-kappa B/metabolismo , Síndrome Nefrótica/sangue , Síndrome Nefrótica/induzido quimicamente , Síndrome Nefrótica/enzimologia , Proteinúria/tratamento farmacológico , Proteinúria/enzimologia , Proteinúria/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Crescimento Transformador beta1/sangue , Fator de Necrose Tumoral alfa/sangueRESUMO
Endothelial nitric oxide synthase (eNOS) deficiency exacerbates proteinuria and renal injury in several glomerular diseases, but the underlying mechanism is not fully understood. We recently showed that heparanase is essential for the development of experimental diabetic nephropathy and glomerulonephritis, and hypothesize that heparanase expression is regulated by eNOS. Here, we demonstrate that induction of adriamycin nephropathy (AN) in C57BL/6 eNOS-deficient mice leads to an increased glomerular heparanase expression accompanied with overt proteinuria, which was not observed in the AN-resistant wild type counterpart. In vitro, the eNOS inhibitor asymmetric dimethylarginine (ADMA) induced heparanase expression in cultured mouse glomerular endothelial cells. Moreover, ADMA enhanced transendothelial albumin passage in a heparanase-dependent manner. We conclude that eNOS prevents heparanase induction and the development of proteinuria.