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1.
Cell Physiol Biochem ; 54(1): 88-109, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31990489

RESUMO

Extracellular vesicles (EVs) are important mediators of intercellular communication. Since EVs are also released during pathological conditions, there has been considerable interest in their potential as sensitive biomarkers of cellular stress and/or injury. In the context of kidney disease, urinary EVs are promising indicators of glomerular and tubular damage. In the present review we discuss the role of urinary EVs in kidney health and disease. Our focus is to explore urinary large EVs (lEVs, often referred to as microparticles or microvesicles) as direct and noninvasive early biomarkers of renal injury. In this regard, studies have been demonstrating altered levels of urinary lEVs, especially podocyte-derived lEVs, preceding the decrease of renal function assessed by classical markers. In addition, we discuss the role of small EVs (sEVs, often referred to as exosomes) and their contents in kidney pathophysiology. Even though results concerning the production of sEVs during diseased conditions are varied, there has been a consensus on the importance of urinary sEV content assessment in kidney disease. These mediators, including EV-released miRNAs and mRNAs, are responsible for EV-mediated signaling in the regulation of renal cellular homeostasis, pathogenesis and regeneration. Finally, steps necessary for the validation of EVs as reliable markers will be discussed.


Assuntos
Vesículas Extracelulares/patologia , Nefropatias/diagnóstico , Glomérulos Renais/patologia , Túbulos Renais/patologia , Animais , Biomarcadores/análise , Biomarcadores/urina , Humanos , Nefropatias/patologia , Nefropatias/urina
2.
N Engl J Med ; 382(5): 416-426, 2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-31995687

RESUMO

BACKGROUND: Acute kidney injury is common, with a major effect on morbidity and health care utilization. Soluble urokinase plasminogen activator receptor (suPAR) is a signaling glycoprotein thought to be involved in the pathogenesis of kidney disease. We investigated whether a high level of suPAR predisposed patients to acute kidney injury in multiple clinical contexts, and we used experimental models to identify mechanisms by which suPAR acts and to assess it as a therapeutic target. METHODS: We measured plasma levels of suPAR preprocedurally in patients who underwent coronary angiography and patients who underwent cardiac surgery and at the time of admission to the intensive care unit in critically ill patients. We assessed the risk of acute kidney injury at 7 days as the primary outcome and acute kidney injury or death at 90 days as a secondary outcome, according to quartile of suPAR level. In experimental studies, we used a monoclonal antibody to urokinase plasminogen activator receptor (uPAR) as a therapeutic strategy to attenuate acute kidney injury in transgenic mice receiving contrast material. We also assessed cellular bioenergetics and generation of reactive oxygen species in human kidney proximal tubular (HK-2) cells that were exposed to recombinant suPAR. RESULTS: The suPAR level was assessed in 3827 patients who were undergoing coronary angiography, 250 who were undergoing cardiac surgery, and 692 who were critically ill. Acute kidney injury developed in 318 patients (8%) who had undergone coronary angiography. The highest suPAR quartile (vs. the lowest) had an adjusted odds ratio of 2.66 (95% confidence interval [CI], 1.77 to 3.99) for acute kidney injury and 2.29 (95% CI, 1.71 to 3.06) for acute kidney injury or death at 90 days. Findings were similar in the surgical and critically ill cohorts. The suPAR-overexpressing mice that were given contrast material had greater functional and histologic evidence of acute kidney injury than wild-type mice. The suPAR-treated HK-2 cells showed heightened energetic demand and mitochondrial superoxide generation. Pretreatment with a uPAR monoclonal antibody attenuated kidney injury in suPAR-overexpressing mice and normalized bioenergetic changes in HK-2 cells. CONCLUSIONS: High suPAR levels were associated with acute kidney injury in various clinical and experimental contexts. (Funded by the National Institutes of Health and others.).


Assuntos
Lesão Renal Aguda/sangue , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Angiografia Coronária/efeitos adversos , Receptores de Ativador de Plasminogênio Tipo Uroquinase/sangue , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Lesão Renal Aguda/etiologia , Lesão Renal Aguda/prevenção & controle , Idoso , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Biomarcadores/sangue , Estado Terminal , Modelos Animais de Doenças , Feminino , Humanos , Unidades de Terapia Intensiva , Túbulos Renais/citologia , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/patologia , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Razão de Chances , Podócitos/efeitos dos fármacos , Podócitos/metabolismo , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/etiologia , Medição de Risco/métodos , Ativador de Plasminogênio Tipo Uroquinase/farmacologia
3.
Life Sci ; 238: 116957, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655195

RESUMO

Epithelial-mesenchymal transition (EMT) and extracellular matrix (ECM) deposition in renal tubular epithelial cells are critical to diabetic nephropathy (DN) pathogenesis, but the underlying mechanisms remain undefined. Bone morphogenetic protein 7 (BMP-7) inhibits EMT and ECM accumulation in renal tubular epithelial cells cultured in presence of high glucose. Meanwhile, miRNA-21 (miR-21) downregulates Smad7, promoting EMT and ECM deposition. However, the association of BMP-7 with miR-21/Smad7 in DN is unknown. Here, NRK-52E cells incubated in presence of high glucose and STZ-induced C57BL diabetic mice were considered in vitro and in vivo models of DN, respectively. In both models, BMP-7 (mRNA/protein) amounts were decreased as well as Smad7 protein expression, while miR-21 expression and TGF-ß1/Smad3 pathway activation were enhanced, accompanied by enhanced EMT and ECM deposition. Further, addition of BMP-7 human recombinant cytokine (rhBMP-7) and injection of the BMP-7 overexpression plasmid in diabetic mice markedly downregulated miR-21 and upregulated Smad7, reduced Smad3 activation without affecting TGF-ß1 amounts, and prevented EMT and ECM accumulation. MiR-21 overexpression in the in vitro model downregulated Smad7, promoted EMT and ECM accumulation without affecting BMP-7 amounts, and miR-21 downregulation reversed it. By interfering with BMP-7 and miR-21 expression in high glucose conditions, miR-21 amounts and Smad3 phosphorylation were further decreased. Smad7 was then upregulated, and EMT and ECM deposition were inhibited; these effects were reversed after miR-21 overexpression. These findings suggest that BMP-7 decreases renal fibrosis in DN by regulating miR-21/Smad7 signaling, providing a theoretical basis for the development of novel and effective therapeutic drugs for DN.


Assuntos
Proteína Morfogenética Óssea 7/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Nefropatias Diabéticas/complicações , Fibrose/prevenção & controle , Regulação da Expressão Gênica , Túbulos Renais/metabolismo , MicroRNAs/antagonistas & inibidores , Animais , Proteína Morfogenética Óssea 7/genética , Células Cultivadas , Transição Epitelial-Mesenquimal , Matriz Extracelular/metabolismo , Fibrose/etiologia , Fibrose/patologia , Túbulos Renais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Fosforilação , Transdução de Sinais , Proteína Smad7/genética , Proteína Smad7/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
4.
Nat Commun ; 10(1): 4148, 2019 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-31515477

RESUMO

Autosomal dominant polycystic kidney disease (ADPKD), caused by mutations in either PKD1 or PKD2 genes, is one of the most common human monogenetic disorders and the leading genetic cause of end-stage renal disease. Unfortunately, treatment options for ADPKD are limited. Here we report the discovery and characterization of RGLS4326, a first-in-class, short oligonucleotide inhibitor of microRNA-17 (miR-17), as a potential treatment for ADPKD. RGLS4326 is discovered by screening a chemically diverse and rationally designed library of anti-miR-17 oligonucleotides for optimal pharmaceutical properties. RGLS4326 preferentially distributes to kidney and collecting duct-derived cysts, displaces miR-17 from translationally active polysomes, and de-represses multiple miR-17 mRNA targets including Pkd1 and Pkd2. Importantly, RGLS4326 demonstrates a favorable preclinical safety profile and attenuates cyst growth in human in vitro ADPKD models and multiple PKD mouse models after subcutaneous administration. The preclinical characteristics of RGLS4326 support its clinical development as a disease-modifying treatment for ADPKD.


Assuntos
MicroRNAs/antagonistas & inibidores , Oligonucleotídeos/uso terapêutico , Doenças Renais Policísticas/tratamento farmacológico , Doenças Renais Policísticas/genética , Animais , Sequência de Bases , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Redes Reguladoras de Genes/efeitos dos fármacos , Células HeLa , Hematopoese/efeitos dos fármacos , Humanos , Túbulos Renais/patologia , Macaca fascicularis , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Oligonucleotídeos/farmacocinética , Oligonucleotídeos/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Distribuição Tecidual/efeitos dos fármacos
5.
Int J Mol Sci ; 20(18)2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31514290

RESUMO

In salt-sensitive hypertension, reactive oxygen species (ROS) play a major role in the progression of renal disease partly through the activation of the mineralocorticoid receptor (MR). We have previously demonstrated that urinary vanin-1 is an early biomarker of oxidative renal tubular injury. However, it remains unknown whether urinary vanin-1 might reflect the treatment effect. The objective of this study was to clarify the treatment effect for renal tubular damage in Dahl salt-sensitive (DS) rats. DS rats (six weeks old) were given one of the following for four weeks: high-salt diet (8% NaCl), high-salt diet plus a superoxide dismutase mimetic, tempol (3 mmol/L in drinking water), high-salt diet plus eplerenone (100 mg/kg/day), and normal-salt diet (0.3% NaCl). After four-week treatment, blood pressure was measured and kidney tissues were evaluated. ROS were assessed by measurements of malondialdehyde and by immunostaining for 4-hydroxy-2-nonenal. A high-salt intake for four weeks caused ROS and histological renal tubular damages in DS rats, both of which were suppressed by tempol and eplerenone. Proteinuria and urinary N-acetyl-ß-D-glucosaminidase exhibited a significant decrease in DS rats receiving a high-salt diet plus eplerenone, but not tempol. In contrast, urinary vanin-1 significantly decreased in DS rats receiving a high-salt diet plus eplerenone as well as tempol. Consistent with these findings, immunohistochemical analysis revealed that vanin-1 was localized in the renal proximal tubules but not the glomeruli in DS rats receiving a high-salt diet, with the strength attenuated by tempol or eplerenone treatment. In conclusion, these results suggest that urinary vanin-1 is a potentially sensitive biomarker for ameliorating renal tubular damage in salt-sensitive hypertension.


Assuntos
Amidoidrolases/metabolismo , Túbulos Renais/patologia , Estresse Oxidativo , Amidoidrolases/urina , Animais , Biomarcadores/sangue , Biomarcadores/urina , Pressão Sanguínea/efeitos dos fármacos , Óxidos N-Cíclicos/farmacologia , Eplerenona/farmacologia , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/fisiopatologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos Endogâmicos Dahl , Marcadores de Spin , Sístole/efeitos dos fármacos
6.
Ann Clin Lab Sci ; 49(4): 439-447, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31471332

RESUMO

Monoclonal gammopathy of renal significance (MGRS) is a state of circulating monoclonal immunoglobulin (Ig) and light chains that cause kidney injury without definite evidence of multiple myeloma (MM). Although chemotherapy is used to treat many variants of MGRS and has been recently recommended, relatively limited clinical validation studies are available. A few transgenic models of MM reveal renal deposition of monoclonal Ig and light chains. We have demonstrated that the XBP1s-transgenic mouse model from early plasma cell dyscrasia to MM reveals monoclonal IgG/kappa deposition at the subendothelial spaces of the glomeruli, mimicking proliferative glomerulonephritis with monoclonal immunoglobulin deposits. Inhibition of a key immune-modulator, gp96/grp94, genetically or pharmacologically results in a significant reduction of plasma cells within the bone marrow and reduced renal deposition of monoclonal IgG and kappa light chain. This article will review the emerging role of in vitro and animal models from plasma cell dyscrasia to MM in understanding the renal deposition of monoclonal Ig and light chains, along with its potential treatment strategies.


Assuntos
Modelos Animais de Doenças , Paraproteinemias/patologia , Animais , Creatinina/sangue , Humanos , Cadeias Leves de Imunoglobulina/metabolismo , Túbulos Renais/lesões , Túbulos Renais/patologia , Paraproteinemias/classificação , Paraproteinemias/diagnóstico , Paraproteinemias/terapia
7.
Kidney Blood Press Res ; 44(4): 777-791, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31408871

RESUMO

BACKGROUND: M2 macrophages have important roles in diseases such as tumours, cardiovascular diseases and renal diseases. This study aimed to determine the effects and protective mechanism of M2 macrophages against oxidative stress injury and apoptosis induced by calcium oxalate crystals (CaOx) in renal tubular epithelial cells (HK-2) under coculture conditions. METHODS: THP-1 cells were induced to differentiate into M2 macrophages by using phorbol-12-myristate-13-acetate, IL-4 and IL-13. Morphological features were observed by microscopy. Phenotypic markers were identified by reverse transcription-polymerase chain reaction, Western blot and enzyme-linked immunosorbent assay (ELISA). HK-2 cells were treated with 0.5 mg/mL CaOx crystals and co-cultured with M2 macrophages or apocynin. The viability of HK-2 cells was detected by CCK-8 assay. The lactate dehydrogenase (LDH) activity of HK-2 cells was analysed using a microplate reader. The apoptosis of HK-2 cells was examined by flow cytometry and Hoechst 33258 staining. Reactive oxygen species (ROS) expression and mitochondrial membrane potential in HK-2 cells were detected by a fluorescence microplate reader. Western blot analysis was conducted to detect the expression of p47phox, Bcl-2, cleaved caspase-3, cytochrome c, p38 MAPK, phospho-p38 MAPK, Akt and phospho-Akt. RESULTS: The results of morphology, reverse transcription-polymerase chain reaction, Western blot and ELISA showed that THP-1 cells were successfully polarised to M2 macrophages. The results of co-culture suggested that M2 macrophages or apocynin significantly increased the cell viability and decreased the LDH activity and apoptosis rate after HK-2 cells were challenged with CaOx crystals. The expression of the p47phox protein and the concentration of ROS were reduced, the release of mitochondrial membrane potential and the expression of the Bcl-2 protein were upregulated and the protein expression of cleaved caspase-3 and cytochrome c was downregulated. The expression of the phosphorylated form of p38 MAPK increased. Under coculture conditions with M2 macrophages, the Akt protein of HK-2 cells treated with CaOx crystals was dephosphorylated, but the phosphorylated form of Akt was not reduced by apocynin. CONCLUSIONS: M2 macrophages reduced the oxidative stress injury and apoptosis of HK-2 cells by downregulating the activation of NADPH oxidase, reducing the production of ROS, inhibiting the phosphorylation of p38 MAPK and enhancing the phosphorylation of Akt. We have revealed one of the possible mechanisms by which M2 macrophages reduce the formation of kidney stones.


Assuntos
Apoptose/efeitos dos fármacos , Oxalato de Cálcio/farmacologia , Túbulos Renais/efeitos dos fármacos , Macrófagos/fisiologia , Estresse Oxidativo , Acetofenonas/farmacologia , Antioxidantes/farmacologia , Linhagem Celular , Técnicas de Cocultura , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Humanos , Cálculos Renais , Túbulos Renais/lesões , Túbulos Renais/patologia , Fosforilação , Espécies Reativas de Oxigênio/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
8.
Food Chem Toxicol ; 133: 110720, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31369848

RESUMO

The incidence of kidney disease has increased rapidly in recent years. One major possible reason for this increase in nephrosis is from foodborne toxins. Since the mechanism of how foodborne toxins are involved in the process of nephrosis is largely unknown, the current study aims to establish a profile for how one of the major toxin threats, ochratoxin A (OTA), induce differential protein expression. In this proteomic study of rat kidneys, 75 kd glucose-regulated protein (Grp75) expression was found to be sensitized by a low concentration of OTA, but inhibited by high doses. In response to OTA, a decrease in Grp75 expression preceded the inhibition of mitochondrial Lon peptidase 1 (Lonp1). Using Grp75 knockdown cell line, it was shown that the inhibition of Grp75 promoted the secretion of kidney injury molecule 1 (Kim1), and suppressed Lonp1 expression in renal injury. Moreover, the acceleration of renal disease was associated with the consumption of Grp75. Our study suggests that the Grp75 protein may be valuable as both a treatment and biomarker for the foodborne diseases that induce renal tubular necrosis. The findings of this research are beneficial for the establishment of nutritional interventions, and the screening of therapeutic targets, in cases of nephrosis.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Túbulos Renais/metabolismo , Proteínas Mitocondriais/metabolismo , Proteases Dependentes de ATP/metabolismo , Animais , Biomarcadores/metabolismo , Moléculas de Adesão Celular/metabolismo , Linhagem Celular , Doenças Transmitidas por Alimentos/metabolismo , Doenças Transmitidas por Alimentos/patologia , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico HSP70/genética , Humanos , Túbulos Renais/patologia , Masculino , Proteínas Mitocondriais/genética , Necrose , Ocratoxinas , Proteômica/métodos , Ratos Endogâmicos F344 , Ratos Wistar , Transcriptoma
9.
Ann Biol Clin (Paris) ; 77(4): 381-389, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31418699

RESUMO

The SFBC working group aimed to deal with biological tests outside the french nomenclature that may be useful in the context of urinary exploration of metabolism. This section will be divides into three parts: 1) nutritional assessment using urinary urea; 2) metabolic assessment of urolithiasis; 3) exploration of tubulopathies. National and international recommendations support the evaluation of nutritional status from urea measurements in urine and dialysate with the following indications: primary metabolic evaluation of urolithiasis patients, monitoring of protein intake in chronic renal failure stage 3 or stage 5D with residual diuresis. For the management of the urolithiasis disease, biomedical tests recommended by the national and international guidelines are the measurement of the urinary density using refractometry in the primary metabolic evaluation as well as the determination of oxalemia in the diagnosis (patients with GFR< 30 mL/min/1.73 m2) and follow-up (patients with GFR< 60 mL/min/1.73 m2) of primary hyperoxaluria. The determination of the bicarbonaturia is retained for the in depth exploration of urolithiasis and tubular acidosis. The measure of chlore in urine is used to evaluate the volume status during metabolic alkalosis and to calculate the urinary anionic gap during metabolic acidosis.


Assuntos
Metabolismo Energético/fisiologia , Nefropatias/diagnóstico , Avaliação Nutricional , Urinálise/métodos , Urolitíase/diagnóstico , Humanos , Nefropatias/patologia , Nefropatias/urina , Túbulos Renais/patologia , Padrões de Referência , Refratometria/métodos , Refratometria/normas , Urinálise/normas , Urolitíase/urina
10.
Adv Exp Med Biol ; 1165: 467-485, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31399980

RESUMO

Hypoxia, one of the most common causes of kidney injury, is a key pathological condition in various kidney diseases. Renal fibrosis is the terminal pathway involved in the continuous progression of chronic kidney disease (CKD), characterized by glomerulosclerosis and tubulointerstitial fibrosis (TIF). Recent studies have shown that hypoxia is a key factor promoting the progression of TIF. Loss of microvasculature, reduced oxygen dispersion, and metabolic abnormality of cells in the kidney are the main causes of the hypoxic state. Hypoxia can, in turn, profoundly affect the tubular epithelial cells, endothelial cells, pericytes, fibroblasts, inflammatory cells, and progenitor cells. In this chapter, we reviewed the critical roles of hypoxia in the pathophysiology of TIF and discussed the potential of anti-hypoxia as its promising therapeutic target.


Assuntos
Hipóxia/patologia , Túbulos Renais/patologia , Insuficiência Renal Crônica/patologia , Células Endoteliais , Fibrose , Humanos
11.
Curr Top Med Chem ; 19(22): 2058-2068, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31400266

RESUMO

BACKGROUND: Envenomation caused by Bothrops alternatus is common in Southern Brazil. Acute Kidney Injury occurs after Bothrops snakebite and more information is necessaryrequired to understand its mechanism. OBJECTIVE: The objective was to evaluate the effect of Bothrops alternatus venom (BaV) on renal cells and rat isolated kidney function. METHODS: Wistar rats (n = 6, weighing 260-320 g) were perfused with a Krebs-Henseleit solution containing 6 g 100 mL-1 of bovine serum albumin. After 30 minutes, the kidneys were perfused with BaV to a final concentration of 1 and 3 µgmL-1; and subsequently were evaluated for Perfusion Pressure (PP), Renal Vascular Resistance (RVR), Urinary Flow (UF), Glomerular Filtration Rate (GFR), and percentage of electrolyte tubular transport. Renal histological analysis, cytokine release, oxidative stress and cytotoxicity in renal proximal tubular cells were assessed. RESULTS: BaV reduced PP, RVR, GFR, UF, total and proximal sodium transport (%TNa+), and chloride (%TCl-) in the isolated kidney perfusion model. Histological analysis of perfused kidneys disclosed the presence of proteinaceous material in the glomeruli and renal tubules, vacuolar tubular epithelial cell degeneration, Bowman's capsule degeneration, swelling of glomerular epithelial cells, glomerular atrophy and degeneration, and the presence of intratubular protein. Cytokine release (TNF-α, IL-1ß, IL-10) and oxidative stress were increased in the kidneys. The viability of LLC-MK2 cells (IC50: 221.3 µg/mL) was decreased by BaV and necrosis was involved in cell death. CONCLUSION: These findings indicate that BaV modifies functional parameters in an isolated perfused kidney model and has cytotoxic effects on renal lineage cells.


Assuntos
Citocinas/biossíntese , Túbulos Renais/efeitos dos fármacos , Venenos de Serpentes/farmacologia , Animais , Bothrops , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Taxa de Filtração Glomerular , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Macaca mulatta , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Relação Estrutura-Atividade
12.
Int J Mol Sci ; 20(14)2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31373312

RESUMO

Diabetic nephropathy is increasingly recognized as a major contributor to kidney failure in patients with obesity and type 2 diabetes. This study was designed to identify the molecular mediators of kidney injury associated with metabolic syndrome with or without hyperglycemia. We compared renal gene expression profiles in Zucker lean (ZL), Zucker obese (ZO), and Zucker diabetic (ZD) rats using cDNA microarray with quantitative verification of selected transcripts by real-time PCR. Compared to the 20-week-old ZL control (glucose: 110 ± 8 mg/dL), both prediabetic ZO (glucose: 157 ± 11 mg/dL) and diabetic ZD (glucose: 481 ± 37 mg/dL) rats displayed hyperlipidemia and kidney injury with a high degree of proteinuria. cDNA microarray identified 25 inflammation and injury-related transcriptomes whose expression levels were similarly increased in ZO and ZD kidneys. Among them, kidney injury molecule-1 (KIM-1) was found to be the most highly upregulated in both ZO and ZD kidneys. Immunofluorescence staining of kidney sections revealed a strong correlation between lipid overload and KIM-1 upregulation in proximal tubules of ZO and ZD rats. In cultured primary renal tubular epithelial cells (TECs), administration of saturated fatty acid palmitate resulted in an upregulation of KIM-1, osteopontin, and CD44, which was greatly attenuated by U0126, an inhibitor of extracellular signal-regulated kinase (ERK)1/2. Moreover, knockdown of KIM-1 by siRNA interference inhibited palmitate-induced cleaved caspase-3, osteopontin, and CD44 proteins in primary TECs. Our results indicate that KIM-1 expression is upregulated in renal lipotoxicity and may play an important role in fatty acid-induced inflammation and tubular cell damage in obesity and diabetic kidney disease.


Assuntos
Moléculas de Adesão Celular/metabolismo , Nefropatias Diabéticas/patologia , Hiperlipidemias/patologia , Túbulos Renais/patologia , Obesidade/patologia , Animais , Caspase 3/biossíntese , Moléculas de Adesão Celular/genética , Perfilação da Expressão Gênica , Receptores de Hialuronatos/biossíntese , Hiperglicemia/patologia , Hiperlipidemias/sangue , Túbulos Renais/lesões , Síndrome Metabólica/patologia , Osteopontina/biossíntese , Palmitatos/toxicidade , Proteinúria/urina , Interferência de RNA , RNA Interferente Pequeno/genética , Ratos , Ratos Zucker , Transcriptoma/genética
13.
Int J Mol Sci ; 20(15)2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31390839

RESUMO

Despite the wide use of angiotensin II receptor blockers in the treatment of Alport syndrome (AS), the mechanism as to how angiotensin II receptor blockers prevent interstitial fibrosis remains unclear. Here, we report that treatment of olmesartan effectively targets the feedback loop between the renin-angiotensin system (RAS) and transforming growth factor ß (TGFß) signals in tubular epithelial cells and preserves renal angiotensin-converting enzyme 2 (ACE2) expression in the kidney of Col4a3-/- mice, a murine model of experimental AS. Morphology analyses revealed amelioration of kidney fibrosis in Col4a3-/- mice by olmesartan treatment. Upregulation of TGFß and activation of its downstream in Col4a3-/- mice were attenuated by olmesartan in Col4a3-/- mice. Intriguingly, TGFß expression was preferentially upregulated in damaged tubular epithelial cells in Col4a3-/- mice. Concurrent upregulation of TNFα-converting enzyme and downregulation of ACE2 suggested RAS activation in Col4a3-/- mice, which was prevented by olmesartan. Mechanistically, olmesartan suppressed TGFß-induced RAS activation in tubular epithelial cells in vitro. Collectively, we concluded that olmesartan effectively suppresses the progression of tubulointerstitial fibrosis in AS by interrupting RAS-TGFß feedback loop to counterbalance intrarenal RAS activation.


Assuntos
Anti-Hipertensivos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Imidazóis/farmacologia , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/metabolismo , Nefrite Hereditária/genética , Nefrite Hereditária/patologia , Tetrazóis/farmacologia , Fator de Crescimento Transformador beta/genética , Animais , Apoptose/efeitos dos fármacos , Biomarcadores , Biópsia , Modelos Animais de Doenças , Fibrose , Túbulos Renais/patologia , Camundongos , Camundongos Knockout , Nefrite Hereditária/tratamento farmacológico , Nefrite Hereditária/metabolismo , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Resultado do Tratamento , Proteínas ras/genética , Proteínas ras/metabolismo
14.
PLoS Negl Trop Dis ; 13(7): e0007567, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31295336

RESUMO

Invasive fungal infections (IFI) is a worldwide serious health problem and Amphotericin B (AmB) has been considered the drug of choice for IFI treatment. Despite its efficacy, clinical use of AmB has been associated with renal toxicity. Some lines of evidence have shown that an extemporaneous lipid emulsion preparation of AmB (AmB/LE) was able to attenuate nephrotoxicity, presenting similar benefits at a lower cost. Studies have been demonstrating that hypovitaminosis D may hasten the progression of kidney disease and reflect on a worse prognosis in cases of drug-induced nephrotoxicity. In view of the high worldwide incidence of hypovitaminosis D, the aim of this study was to investigate whether vitamin D deficiency may induce AmB/LE-related nephrotoxicity. Wistar rats were divided into four groups: control, received a standard diet for 34 days; AmB/LE, received a standard diet for 34 days and AmB/LE (5 mg/kg/day) intraperitoneally in the last 4 days; VDD, received a vitamin D-free diet for 34 days; and VDD+AmB/LE, received a vitamin D-free diet for 34 days and AmB/LE as described. At the end of the protocol, animals were euthanized and blood, urine and renal tissue samples were collected in order to evaluate AmB/LE effects on renal function and morphology. Association of AmB/LE and vitamin D deficiency led to diminished glomerular filtration rate and increased tubular injury, evidenced by reduced renal protein expression of NaPi-IIa and TRPM6 leading to hyperphosphaturia / hypermagnesuria. VDD+AmB/LE rats also presented alterations in the PTH-Klotho-FGF-23 signaling axis, urinary concentrating defect and hypertension, probably due to an inappropriate activation of the renin-angiotensin-aldosterone system. Hence, it is important to monitor vitamin D levels in AmB/LE treated patients, since vitamin D deficiency induces AmB/LE nephrotoxicity.


Assuntos
Anfotericina B/efeitos adversos , Antifúngicos/efeitos adversos , Rim/efeitos dos fármacos , Deficiência de Vitamina D/complicações , Animais , Testes de Função Renal , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/patologia , Masculino , Ratos Wistar , Fatores de Risco
15.
Biomed Res Int ; 2019: 9013904, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275989

RESUMO

Background: It has been documented that vitamin D supplementation showed an improvement of symptoms of diabetic nephropathy; however, the underlying mechanisms remain unknown. We here tested the hypothesis that active vitamin D is able to up-regulate AKT/UCP2 signaling to alleviate oxidative stress of renal tubular cell line HK2. Methods: There are eight groups in the present study: normal glucose, osmotic control (5.5 mmol/L D-glucose+24.5 mmol/L D-mannitol), NAC control (30 mmol/L D-glucose + 1.0 mmol/L N-Methylcysteine), high glucose, high glucose+VD, high glucose (HG)+VD+siVDR, HG+VD+AKT inhibitor (AI), and high glucose+VD+UCP2 inhibitor (Gelipin). Concentration of superoxide dismutase (SOD) and malondialdehyde (MDA) was analyzed by ELISA. Reactive oxygen species (ROS), mitochondrial membrane potential and apoptosis were measured by flow cytometry. JC-1 was evaluated by flow cytometry. The presence of VDR, AKT, and UCP2 in HK cells was assessed using RT-PCR and western blot analyses. Results: VD administration significantly upregulated the SOD activation and downregulated MDA levels compared to HG group. siVDR, AKT inhibitor, and UCP2 inhibitor significantly suppressed the activation of SOD and increased the expression of MDA compared to VD group. ROS generation and apoptosis of HK2 cells in HG+VD group were significantly lower than those in HG, HG+VD+siVDR, HG+VD+AI, and HG+VD+Gelipin group. ΔΨm in HG+VD group was obviously higher than those in HG, HG+VD+siVDR, HG+VD+AI, and HG+VD+Gelipin group. Decreased mRNA and protein levels of VDR, p-AKT, and UCP2 were observed in HG+VD+siVDR, HG+VD+AI, and HG+VD+Gelipin group compared to those in HG+VD group. Conclusions: siVDR, AKT inhibitor, and UCP2 inhibitor elevated the ROS and apoptosis of HK2 cells while attenuating the mitochondrial membrane potential, suggesting that vitamin D protects renal tubular cell from high glucose by AKT/UCP2 signaling pathway.


Assuntos
Glucose/toxicidade , Túbulos Renais/patologia , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Calcitriol/metabolismo , Transdução de Sinais , Proteína Desacopladora 2/metabolismo , Vitamina D/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Humanos , Malondialdeído/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
16.
Mol Med Rep ; 20(2): 1613-1620, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31257491

RESUMO

Renal tubular epithelial cell apoptosis is an important pathological mechanism of septic acute kidney injury (AKI). Endotoxin, also known as lipopolysaccharide (LPS), has a key role in septic AKI and can directly induce tubular epithelial cell apoptosis. The upregulation of receptor­interacting protein kinase 3 (RIPK3) in tubular epithelial cells has been reported in septic AKI, with RIPK3 mediating apoptosis in several cell types. In the present study, the effect of RIPK3 on endotoxin­induced AKI was investigated in mouse tubular epithelial cell apoptosis in vitro and in vivo. It was found that the expression of RIPK3 was markedly increased in endotoxin­induced AKI. Endotoxin­induced AKI and tubular epithelial cell apoptosis could be attenuated by GSK'872, a RIPK3 inhibitor. LPS stimulation also upregulated RIPK3 expression in tubular epithelial cells in a time­dependent manner. Both RIPK3 inhibitor and small interfering RNA (siRNA) targeting RIPK3 reduced LPS­induced tubular epithelial cell apoptosis in vitro. The expression of the proapoptotic protein Bax was induced by LPS and reversed by GSK'872 or RIPK3­siRNA. The present study revealed that RIPK3 mediated renal tubular cell apoptosis in endotoxin­induced AKI. RIPK3 may be a potential target for the prevention of renal tubular cell apoptosis in endotoxin­induced AKI.


Assuntos
Lesão Renal Aguda/metabolismo , Células Epiteliais/patologia , Túbulos Renais/patologia , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/patologia , Animais , Apoptose , Células Cultivadas , Modelos Animais de Doenças , Endotoxinas/efeitos adversos , Células Epiteliais/metabolismo , Túbulos Renais/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Proteína Serina-Treonina Quinases de Interação com Receptores/análise
17.
Life Sci ; 233: 116666, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325427

RESUMO

AIM: Pirfenidone (PFD) has been used as medication for idiopathic pulmonary fibrosis due to its ability in reducing lung fibrosis. However, the underlying mode of action in renal fibrosis during chronic renal allograft dysfunction (CRAD) requires further investigation. Therefore, the present study was conducted to explore the effects of PFD on renal injury induced by CRAD. MAIN METHODS: Initially, the CRAD rat model was established, followed by the intragastric administration of PFD to the rats. Urine and blood samples were collected and tested against indicators of renal functions. The renal tissues were microscopically observed to determine the changes in pathological morphology. The anti-inflammatory, anti-fibrotic and anti-oxidant properties of PFD were explored in the setting of CRAD. KEY FINDINGS: The success rate of model establishment was 92.31%, which was reflected by weight loss, appetite loss, faded fur, and retarded reaction, with the symptoms found to exacerbate with time. PFD treatment could improve renal function, ameliorate inflammation and renal fibrosis as well as promote the anti-oxidant ability of renal allograft, indicating its potential role as an effective therapeutic agent for CRAD. SIGNIFICANCE: In conclusion, PFD was found to have renoprotective effects on renal injury induced by CRAD, which resulted in the alleviation of inflammation and renal fibrosis, providing novelty for CRAD clinical treatment.


Assuntos
Fibrose/prevenção & controle , Rejeição de Enxerto/prevenção & controle , Transplante de Rim/efeitos adversos , Túbulos Renais/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Piridonas/farmacologia , Insuficiência Renal Crônica/cirurgia , Aloenxertos , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Doença Crônica , Fibrose/etiologia , Rejeição de Enxerto/etiologia , Túbulos Renais/patologia , Masculino , Ratos , Ratos Endogâmicos F344 , Ratos Endogâmicos Lew
18.
Ren Fail ; 41(1): 455-466, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31163002

RESUMO

Purpose: To investigate whether Niban protein plays a role in renal interstitial fibrosis by regulating renal tubular epithelial cell apoptosis and explore the underlying mechanism. Methods: Unilateral ureteral obstruction (UUO) model was performed in C57B/6J mice, and divided into sham operation group and groups of days 3, days 7, and days 14. Niban expression was detected by immunohistochemistry and Western blot. TUNEL assays were used to detected apoptosis. Niban siRNA and overexpression Niban plasmid were transfected in HK-2 cells respectively to explore apoptosis related mechanisms of Niban during angiotensin II (AngII) - and endoplasmic reticulum (ER) stress-induced injury. Results: With the development of obstruction, Niban's expression decreased gradually while apoptosis increased. Silencing of Niban not only increased the AngII- and ER stress-induced apoptosis, but also promoted the expression of caspase 8, caspase 9, Bip, and Chop. Overexpression of Niban reduced AngII-induced apoptosis and the expression of caspase 8 and caspase 9. Conclusions: Niban protein is involved in apoptosis regulation in HK-2 cells, and most likely via caspase-dependent pathway.


Assuntos
Apoptose , Biomarcadores Tumorais/metabolismo , Nefropatias/patologia , Túbulos Renais/patologia , Proteínas de Neoplasias/metabolismo , Animais , Biomarcadores Tumorais/genética , Caspase 8/metabolismo , Caspase 9/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático , Células Epiteliais , Fibrose , Humanos , Nefropatias/etiologia , Túbulos Renais/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Neoplasias/genética , RNA Interferente Pequeno , Obstrução Ureteral/complicações
19.
Life Sci ; 230: 197-207, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31150688

RESUMO

AIMS: Increased amounts of protein, in particular albumin within renal tubular cells (TBCs), induce the expression of inflammatory and fibrogenic mediators, which are adverse prognostic factors in tubulointerstitial fibrosis and diabetic nephropathy (DN). We sought to assess the participation of the thiol-linked tertiary structure of albumin in the mechanism of protein toxicity in a model of TBCs. MATERIALS AND METHODS: Cultured human renal proximal tubular cells, HK-2, were exposed to isolated albumin from patients with and without DN (Stages 0, 1 and 4). The magnitude of change of the albumin tertiary structure, cell viability (LDH leakage), apoptosis (Annexin V), transdifferentiation and reticulum endoplasmic stress (Western blot and flow cytometry) and lysosomal enzyme activity were assessed. KEY FINDINGS: We found that albumin from Stage 4 patients presented >50% higher thiol-dependent changes of tertiary structure compared to Stages 0 and 1. Cells incubated with Stage 4 albumin displayed 5 times less viability, accompanied by an increased number of apoptotic cells; evidence of profibrogenic markers E-cadherin and vimentin and higher expression of epithelial-to-mesenchymal transition markers α-SMA and E-cadherin and of endoplasmic reticulum stress protein GRP78 were likewise observed. Moreover, we found that cathepsin B activity in isolated lysosomes showed a significant inhibitory effect on albumin from patients in advanced stages of DN and on albumin that was intentionally modified. SIGNIFICANCE: Overall, this study showed that thiol-dependent changes in albumin's tertiary structure interfere with the lysosomal proteolysis of renal TBCs, inducing molecular changes associated with interstitial fibrosis and DN progression.


Assuntos
Nefropatias Diabéticas/metabolismo , Lisossomos/fisiologia , Albumina Sérica Humana/fisiologia , Adulto , Idoso , Albuminas/metabolismo , Apoptose/efeitos dos fármacos , Caderinas/metabolismo , Linhagem Celular , Sobrevivência Celular , Transdiferenciação Celular , Nefropatias Diabéticas/fisiopatologia , Estresse do Retículo Endoplasmático , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Fibrose , Humanos , Túbulos Renais/patologia , Masculino , Pessoa de Meia-Idade , Cultura Primária de Células , Estrutura Terciária de Proteína/fisiologia , Albumina Sérica Humana/metabolismo , Transdução de Sinais/efeitos dos fármacos , Vimentina/metabolismo
20.
Ren Fail ; 41(1): 481-488, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31169440

RESUMO

Background: Renal interstitial fibrosis is a common pathway of chronic kidney disease to end-stage renal disease, which is characterized by an imbalance between the synthesis and degradation of the collagen-rich extracellular matrix (ECM). While, discoidin domain receptor 2 (DDR2) can be activated when it binds to some types of collagen. Therefore, we hypothesized that DDR2 may be a major player in renal interstitial fibrosis. Methods: Renal histologic analysis, real-time PCR analyses and hydroxyproline assay were performed in DDR2-deficient mice and wild-type mice after unilateral ureteral obstruction; C57 mice were randomly divided into sham operation group (Sham group, n = 4), renal interstitial fibrosis model group (UUO group, n = 4), and calcium dobesilate treatment group (CDT group, n = 4), preparation of renal interstitial fibrosis model by unilateral ureteral obstruction (UUO), CDT Group was treated with calcium dobesilate orally, Sham group and UUO group were given double distilled water, HE staining, Masson staining, real-time quantitative PCR were detected after 14 days of UUO in mice to observe the renal interstitial fibrosis degree. Results: DDR2 expression was dramatically increased in the obstructed kidney; In contrast to wild-type mice that developed severe interstitial fibrosis, the DDR2-deficient mice displayed only moderate fibrotic changes; Compared with the UUO group, the degree of renal interstitial fibrosis in CDT group was relieved after operation 14 day. Conclusion: DDR2 might play an important role in the development of RIF; Calcium dobesilate can affect the expression of DDR2 and improve the renal interstitial fibrosis in mice.


Assuntos
Receptor com Domínio Discoidina 2/metabolismo , Túbulos Renais/patologia , Insuficiência Renal Crônica/patologia , Administração Oral , Animais , Dobesilato de Cálcio/administração & dosagem , Receptor com Domínio Discoidina 2/genética , Modelos Animais de Doenças , Progressão da Doença , Fibrose , Humanos , Túbulos Renais/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/tratamento farmacológico , Deleção de Sequência , Índice de Gravidade de Doença , Obstrução Ureteral/complicações
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