RESUMO
Dysfunction of mesangial cells plays a major role in the pathogenesis of diabetic kidney disease (DKD), the leading cause of kidney failure. However, the underlying molecular mechanisms are incompletely understood. By unbiased gene expression analysis of glucose-exposed mesangial cells, we identified the transmembrane receptor CD248 as the most upregulated gene, and the maladaptive unfolded protein response (UPR) as one of the most stimulated pathways. Upregulation of CD248 was further confirmed in glucose-stressed mesangial cells in vitro, in kidney glomeruli isolated from diabetic mice (streptozotocin; STZ and db/db models, representing type 1 and type 2 diabetes mellitus, respectively) in vivo, and in glomerular kidney sections from patients with DKD. Time course analysis revealed that glomerular CD248 induction precedes the onset of albuminuria, mesangial matrix expansion and maladaptive UPR activation (hallmarked by transcription factor C/EBP homologous protein (CHOP) induction) but is paralleled by loss of the adaptive UPR regulator spliced X box binding protein (XBP1). Mechanistically, CD248 promoted maladaptive UPR signaling via inhibition of the inositol requiring enzyme 1α (IRE1α)-mediated transcription factor XBP1 splicing in vivo and in vitro. CD248 induced a multiprotein complex comprising heat shock protein 90, BH3 interacting domain death agonist (BID) and IRE1α, in which BID impedes IRE1α-mediated XBP1 splicing and induced CHOP mediated maladaptive UPR signaling. While CD248 knockout ameliorated DKD-associated glomerular dysfunction and reverses maladaptive unfolded protein response signaling, concomitant XBP1 deficiency abolished the protective effect in diabetic CD248 knockout mice, supporting a functional interaction of CD248 and XBP1 in vivo. Hence, CD248 is a novel mesangial cell receptor inducing maladaptive UPR signaling in DKD.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Animais , Camundongos , Antígenos CD/metabolismo , Antígenos de Neoplasias , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/genética , Nefropatias Diabéticas/genética , Endorribonucleases/genética , Endorribonucleases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Fatores de Transcrição/metabolismo , Resposta a Proteínas não Dobradas , HumanosRESUMO
Tau is a cytoskeletal protein that is expressed mainly in neurons and is involved in several cellular processes, such as microtubule stabilization, axonal maintenance, and transport. Altered tau metabolism is related to different tauopathies being the most important Alzheimer's disease where aberrant hyperphosphorylated and aggregated tau is found in the central nervous system. Here, we have analyzed that function in kidney by using tau knockout mice generated by integrating GFP-encoding cDNA into exon 1 of MAPT (here referred to as TauGFP/GFP). IVIS Lumina from PerkinElmer demonstrated GFP expression in the kidney. We then demonstrated by qPCR that the main tau isoform in the kidney is Tau4R. The GFP reporter allowed us to demonstrate that tau is found in the glomeruli of the renal cortex, and specifically in podocytes. This was further confirmed by immunohistochemistry. TauGFP/GFP mice present a podocyte cytoskeleton more dynamic as they contain higher levels of detyrosinated tubulin than wild-type mice. In addition, transmission electron microscopy studies demonstrated glomerular damage with a decrease in urinary creatinine. Our results prove that tau has an important role in kidney metabolism under normal physiological conditions.
Assuntos
Rim/metabolismo , Microtúbulos/metabolismo , Podócitos/metabolismo , Tauopatias/metabolismo , Proteínas tau/metabolismo , Animais , Citoesqueleto/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Rim/citologia , Rim/ultraestrutura , Glomérulos Renais/metabolismo , Glomérulos Renais/ultraestrutura , Camundongos da Linhagem 129 , Camundongos Knockout , Camundongos Transgênicos , Microscopia Confocal , Microscopia Imunoeletrônica , Tauopatias/genética , Proteínas tau/genéticaRESUMO
The impact of cadmium (Cd) on the function and structure of the kidney and the potential protective effect of an extract from Aronia melanocarpa L. berries were investigated in a rat model of low- and moderate-level environmental exposure to this heavy metal (1 and 5 mg Cd/kg feed for up to 24 months). The sensitive biomarkers of Cd-induced damage to the kidney tubules (N-acetyl-ß-D-glucosaminidase (NAG), alkaline phosphatase (ALP), ß2-microglobulin (ß2-MG), and kidney injury molecule-1 (KIM-1) in the urine), clinically relevant early markers of glomerular damage (albumin in the urine and creatinine clearance), and other markers of the general functional status of this organ (urea, uric acid, and total protein in the serum and/or urine) and Cd concentration in the urine, were evaluated. The morphological structure of the kidney and inflammatory markers (chemerin, macrophage inflammatory protein 1 alpha (MIP1a), and Bcl2-associated X protein (Bax)) were also estimated. Low-level and moderate exposure to Cd led to damage to the function and structure of the kidney tubules and glomeruli. The co-administration of A. melanocarpa berry extract significantly protected against the injurious impact of this toxic element. In conclusion, even low-level, long-term exposure to Cd poses a risk of kidney damage, whereas an intake of Aronia berry products may effectively protect from this outcome.
Assuntos
Nefropatias , Photinia , Humanos , Ratos , Animais , Cádmio/metabolismo , Photinia/química , Ratos Wistar , Frutas/metabolismo , Exposição Ambiental , Nefropatias/induzido quimicamente , Nefropatias/tratamento farmacológico , Nefropatias/prevenção & controle , Rim/metabolismo , Modelos Animais , Acetilglucosaminidase/urinaRESUMO
Intrauterine growth restriction (IUGR) due to an adverse intrauterine environment predisposes to arterial hypertension and loss of kidney function. Here, we investigated whether vascular dysregulation in renal interlobar arteries (RIAs) may contribute to hypertensive glomerular damage after IUGR. In rats, IUGR was induced by bilateral uterine vessel ligation. Offspring of nonoperated rats served as controls. From postnatal day 49, blood pressure was telemetrically recorded. On postnatal day 70, we evaluated contractile function in RIAs and mesenteric arteries. In addition, blood, urine, and glomerular parameters as well as renal collagen deposition were analyzed. IUGR RIAs not only showed loss of stretch activation in 9 of 11 arteries and reduced stretch-induced myogenic tone but also showed a shift of the concentration-response relation of acetylcholine-induced relaxation toward lower concentrations. However, IUGR RIAs also exhibited augmented contractions through phenylephrine. Systemic mean arterial pressure [mean difference: 4.8 mmHg (daytime) and 5.7 mmHg (night)], mean glomerular area (IUGR: 9,754 ± 338 µm2 and control: 8,395 ± 227 µm2), and urinary protein-to-creatinine ratio (IUGR: 1.67 ± 0.13 g/g and control: 1.26 ± 0.10 g/g) were elevated after IUGR. We conclude that male IUGR rat offspring may have increased vulnerability toward hypertensive glomerular damage due to loss of myogenic tone and augmented endothelium-dependent relaxation in RIAs.NEW & NOTEWORTHY For the first time, our study presents wire myography data from renal interlobar arteries (RIAs) and mesenteric arteries of young adult rat offspring after intrauterine growth restriction (IUGR). Our data indicate that myogenic tone in RIAs is dysfunctional after IUGR. Furthermore, IUGR offspring suffer from mild arterial hypertension, glomerular hypertrophy, and increased urinary protein-to-creatinine ratio. Dysregulation of vascular tone in RIAs could be an important variable that impacts upon vulnerability toward glomerular injury after IUGR.
Assuntos
Retardo do Crescimento Fetal/metabolismo , Hipertensão/fisiopatologia , Rim/metabolismo , Artéria Renal/fisiopatologia , Animais , Pressão Sanguínea/fisiologia , Retardo do Crescimento Fetal/fisiopatologia , Rim/efeitos dos fármacos , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Fenilefrina/farmacologia , RatosRESUMO
Following our previous reports on mesangial sclerosis and vascular proliferation in diabetic nephropathy (DN) (Kriz W, Löwen J, Federico G, van den Born J, Gröne E, Gröne HJ. Am J Physiol Renal Physiol 312: F1101-F1111, 2017; Löwen J, Gröne E, Gröne HJ, Kriz W. Am J Physiol Renal Physiol 317: F399-F410, 2019), we now describe the advanced stages of DN terminating in glomerular obsolescence and tubulointerstitial fibrosis based on a total of 918 biopsies. The structural aberrations emerged from two defects: 1) increased synthesis of glomerular basement membrane (GBM) components by podocytes and endothelial cells leading to an accumulation of GBM material in the mesangium and 2) a defect of glomerular vessels consisting of increased leakiness and an increased propensity to proliferate. Both defects may lead to glomerular degeneration. The progressing compaction of accumulated worn-out GBM material together with the retraction of podocytes out of the tuft and the collapse and hyalinosis of capillaries results in a shrunken tuft that fuses with Bowman's capsule (BC) to glomerular sclerosis. The most frequent pathway to glomerular decay starts with local tuft expansions that result in contacts of structurally intact podocytes to the parietal epithelium initiating the formation of tuft adhesions, which include the penetration of glomerular capillaries into BC. Exudation of plasma from such capillaries into the space between the parietal epithelium and its basement membrane causes the formation of insudative fluid accumulations within BC spreading around the glomerular circumference and, via the glomerulotubular junction, onto the tubule. Degeneration of the corresponding tubule develops secondarily to the glomerular damage, either due to cessation of filtration in cases of global sclerosis or due to encroachment of the insudative spaces. The degenerating tubules induce the proliferation of myofibroblasts resulting in interstitial fibrosis.NEW & NOTEWORTHY Based on analysis of 918 human biopsies, essential derangement in diabetic nephropathy consists of accumulation of worn-out glomerular basement membrane in the mesangium that may advance to global sclerosis. The most frequent pathway to nephron dropout starts with the penetration of glomerular capillaries into Bowman's capsule (BC), delivering an exudate into BC that spreads around the entire glomerular circumference and via the glomerulotubular junction onto the tubule, resulting in glomerular sclerosis and chronic tubulointerstitial damage.
Assuntos
Nefropatias Diabéticas/patologia , Glomerulonefrite/patologia , Néfrons/patologia , Biópsia , Cápsula Glomerular/patologia , Capilares/patologia , Permeabilidade Capilar , Nefropatias Diabéticas/metabolismo , Progressão da Doença , Células Endoteliais/patologia , Fibrose , Membrana Basal Glomerular/patologia , Glomerulonefrite/metabolismo , Humanos , Microscopia Eletrônica de Transmissão , Neovascularização Patológica , Néfrons/metabolismo , Néfrons/ultraestrutura , Podócitos/patologiaRESUMO
BACKGROUND/AIMS: Hepatitis C virus (HCV) has been identified in tubular epithelial cells of infected patients; however, the presence of tubular dysfunction, which is a risk factor for chronic kidney disease (CKD), has never been examined in vivo. The present prospective longitudinal study aimed to estimate the prevalence of tubular dysfunction alone or with glomerular damage and its evolution after HCV clearance in cirrhotic patients. METHODS: One hundred and thirty-five consecutive Child-Pugh A cirrhotic patients were evaluated before antiviral treatment and 6 months after the end of therapy. Tubular dysfunction was evaluated by urinary alpha1-microglobulin to creatinine ratio (α1-MCR), and glomerular damage was assessed by urinary albumin to creatinine ratio (ACR). RESULTS: Almost all the patients (93.3%) showed a normal or mildly decreased e-GFR (KDIGO-G1/G2-categories). Tubular dysfunction was found in 23.7% (32/135) of patients, co-occurring with glomerular damage in 37.5% (12/32) of cases, while glomerular damage was found in 16.3% (22/135) of patients. In multiple logistic regression, glomerular damage and the concomitant presence of diabetes and hypertension were the only predictors significantly associated with tubular dysfunction. After HCV clearance, patients experienced a significant reduction of α1-MCR levels (21.0 vs 10.5 µg/mg, P = .009) and tubular dysfunction resolved in 57.1% of subjects. CONCLUSIONS: Tubular dysfunction is an unrecognized feature of HCV-related kidney disease in cirrhotic patients and its presence should be primarily investigated in subjects with glomerular damage, diabetes and hypertension, despite normal e-GFR. Tubular dysfunction resolves in the majority of cases after HCV clearance; however, it may persist after antiviral treatment and further studies should evaluate its long-term impact on kidney function.
Assuntos
Hepatite C Crônica , Hepatite C , Antivirais/uso terapêutico , Hepacivirus , Hepatite C/complicações , Hepatite C/tratamento farmacológico , Hepatite C/epidemiologia , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Humanos , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/epidemiologia , Estudos Longitudinais , Estudos Prospectivos , Resposta Viral SustentadaRESUMO
The genetic variations of the apolipoprotein L1 (APOL1) gene are associated with non-diabetic kidney diseases. However, very little is known about the role of ApoL1 in glomerular damage. Here, we aimed to identify the function and mechanism of ApoL1 in glomerular damage. The mice were randomly divided into two groups: one group was intraperitoneally injected with phosphate buffer saline (PBS), while the other group was intraperitoneally injected with recombinant ApoL1 every other day for 3 months. Hematoxylin and eosin (HE) and periodic acid Schiff (PAS) staining were used to demonstrate the effects of ApoL1 on kidney inflammation and injury. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) analyses revealed that ApoL1-treated mice exhibited enhanced expression of various inflammation markers in the kidney and serum compared to the PBS-treated mice. Immunofluorescence staining revealed that ApoL1 accumulated in kidney podocytes. Treatment with ApoL1 dose-dependently increased the expression of inflammation markers and apoptotic markers. The abnormal gene expression associated with ApoL1-mediated podocyte inflammation was evaluated using microarray analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that the upregulated genes were enriched in the inflammation-related processes, such as the RIG-I/NF-κB signaling pathway. Consistently, the knockdown of RIG-I significantly mitigated the ApoL1-induced upregulation of inflammatory and apoptotic markers in the human podocytes. Additionally, the ApoL1-induced glomerular damage was attenuated in AAV-shRIG-I mice. Therefore, the effects of ApoL1 on glomerular damage may be, at least partially, through inducing abnormal expression of inflammatory molecules, which may have important implications for treatment of kidney diseases.
Assuntos
Apolipoproteína L1/metabolismo , Proteína DEAD-box 58/metabolismo , Inflamação/patologia , Rim/patologia , NF-kappa B/metabolismo , Nefrite/patologia , Animais , Linhagem Celular , Humanos , Inflamação/metabolismo , Rim/metabolismo , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Masculino , Camundongos Endogâmicos C57BL , Nefrite/metabolismo , Podócitos/metabolismoRESUMO
Nephrotic Syndrome (NS) is a rare diseases (around 2-7 cases per 100.000 children per year) characterized by proteinuria ≥50 mg/kg/day (or ≥40 mg/m2/h) or a proteinuria/creatininuria ratio >2 (mg/mg); hypoalbuminaemia less than 25 g/l and edema. The protein leakage, with the consequent hypoalbunaemia and edema, due to podocyte alterations may be caused by genetic diseases, immunological mechanisms, infections, toxins or malignancy. However, most commonly the exact etiology is unknow. The idiopathic NS may be classified based on response to corticosteroid therapy or the hytological appearance. The first classification identifies steroid-resistant NS (no response after 4 weeks of steroid therapy); frequently relapsing NS (≥ 2 relapses in first 6 months or ≥4 relapses in 1-year); steroid dependent NS (relapses during steroid decalage or within 2 weeks from steroid therapy interruption). The hystological classification is based on light and electron microscopy after renal biopsy, which is indicated in case of onset disease before 1 year or after 12 years of age. Macroscopic hematuria: persistent hypertension and/or microscopic hematuria and/or low plasma C3 renal failure not related to hypovolemia; steroid resistence: secondary or relatedsyndromes NS. Minimal change disease (MCD) is the most common form of idiopahtic NS in children, with good response to steroid treatment, and it is characterized by normal glomerular appearance on light microscopy and evidence of podocyte foot alterations on electron microscopy, due to immunological related damage. Focal segmental glomerulosclerosis (FSGS) is described inidiopahtic NS, particularly in steroiddependent or steroid-resistant forms, and is characterized by evidence of focal glomerular damage with secondary sclerosis and adhesion with Bowman's capsule; the electron appearance is the same of MCD one. Recent authors hypotizethat the FSGS is an evolution of MCD. These 2 idiopathic NS forms may be expression of the same immunological disease, with 2 different severity grades; so they may be considered different moments of the same disease spectrum. Less common idiopathic NS forms are membrano proliferative glomerulonephritis; membranous nephropathy; IgM-nephropathy; C1q nephropathy and thin basement membrane disease (1, 2, 3).
Assuntos
Síndrome Nefrótica/imunologia , Criança , Glomerulosclerose Segmentar e Focal/patologia , Hematúria/patologia , Humanos , Podócitos , Proteinúria/patologiaRESUMO
Hyperuricemia has been recognized as a risk factor for insulin resistance as well as one of the factors leading to diabetic kidney disease (DKD). Since DKD is the most common cause of end-stage renal disease, we investigated whether febuxostat, a xanthine oxidase (XO) inhibitor, exerts a protective effect against the development of DKD. We used KK-Ay mice, an established obese diabetic rodent model. Eight-week-old KK-Ay mice were provided drinking water with or without febuxostat (15 µg/mL) for 12 weeks and then subjected to experimentation. Urine albumin secretion and degrees of glomerular injury judged by microscopic observations were markedly higher in KK-Ay than in control lean mice. These elevations were significantly normalized by febuxostat treatment. On the other hand, body weights and high serum glucose concentrations and glycated albumin levels of KK-Ay mice were not affected by febuxostat treatment, despite glucose tolerance and insulin tolerance tests having revealed febuxostat significantly improved insulin sensitivity and glucose tolerance. Interestingly, the IL-1ß, IL-6, MCP-1, and ICAM-1 mRNA levels, which were increased in KK-Ay mouse kidneys as compared with normal controls, were suppressed by febuxostat administration. These data indicate a protective effect of XO inhibitors against the development of DKD, and the underlying mechanism likely involves inflammation suppression which is independent of hyperglycemia amelioration.
Assuntos
Anti-Inflamatórios/uso terapêutico , Nefropatias Diabéticas/tratamento farmacológico , Febuxostat/uso terapêutico , Xantina Oxidase/antagonistas & inibidores , Animais , Peso Corporal/efeitos dos fármacos , Quimiocina CCL2/metabolismo , Colágeno/metabolismo , Nefropatias Diabéticas/imunologia , Intolerância à Glucose/tratamento farmacológico , Hiperglicemia/tratamento farmacológico , Hiperuricemia/tratamento farmacológico , Molécula 1 de Adesão Intercelular/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Glomérulos Renais/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Estresse Oxidativo/efeitos dos fármacos , Fragmentos de Peptídeos/metabolismo , Ácido Úrico/sangueRESUMO
AIMS/HYPOTHESIS: Animal models of diabetic nephropathy show increased levels of glomerular vascular endothelial growth factor (VEGF)-A, and several studies have shown that inhibiting VEGF-A in animal models of diabetes can prevent albuminuria and glomerular hypertrophy. However, in those studies, treatment was initiated before the onset of kidney damage. Therefore, the aim of this study was to investigate whether transfecting mice with the VEGF-A inhibitor sFlt-1 (encoding soluble fms-related tyrosine kinase 1) can reverse pre-existing kidney damage in a mouse model of type 1 diabetes. In addition, we investigated whether transfection with sFlt-1 can reduce endothelial activation and inflammation in these mice. METHODS: Subgroups of untreated 8-week-old female C57BL/6J control (n = 5) and diabetic mice (n = 7) were euthanised 5 weeks after the start of the experiment in order to determine the degree of kidney damage prior to treatment with sFLT-1. Diabetes was induced with three i.p. injections of streptozotocin (75 mg/kg) administered at 2 day intervals. Diabetic nephropathy was then investigated in diabetic mice transfected with sFlt-1 (n = 6); non-diabetic, non-transfected control mice (n = 5); non-diabetic control mice transfected with sFlt-1(n = 10); and non-transfected diabetic mice (n = 6). These mice were euthanised at the end of week 15. Transfection with sFlt-1 was performed in week 6. RESULTS: We found that transfection with sFlt-1 significantly reduced kidney damage by normalising albuminuria, glomerular hypertrophy and mesangial matrix content (i.e. glomerular collagen type IV protein levels) (p < 0.001). We also found that transfection with sFlt-1 reduced endothelial activation (p < 0.001), glomerular macrophage infiltration (p < 0.001) and glomerular TNF-α protein levels (p < 0.001). Finally, sFLT-1 decreased VEGF-A-induced endothelial activation in vitro (p < 0.001). CONCLUSIONS/INTERPRETATION: These results suggest that sFLT-1 might be beneficial in treating diabetic nephropathy by inhibiting VEGF-A, thereby reducing endothelial activation and glomerular inflammation, and ultimately reversing kidney damage.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Albuminúria/metabolismo , Animais , Nefropatias Diabéticas/metabolismo , Modelos Animais de Doenças , Feminino , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: In renal diseases, earlier injury to glomerular may lead to the abscission of podocyte. The number of podocyte in urine may reflect the severity of glomerular damage. Podocalyxin (PCX) was considered as a podocyte marker. Many methods were used to detect podocyte. Applications of these methods were limited by tricky, expensive, and low accuracy. Here, we improved an immunocytochemical method to count the number of podocyte in urine. METHODS: In this study, we counted the numbers of podocyte in urine by our improved method and detected the PCX levels in urine by enzyme-linked immunosorbent assay (ELISA) in glomerulopathy patients and healthy controls. The serum levels of cystatin C (CysC), blood urea nitrogen (BUN), creatinine (CR), uric acid (URIC), and ß2-Microglobulin (ß2-MG) in all subjects were detected. Correlation analysis and diagnostic efficiencies comparisons among immuocytochemical method, ELISA, and the biochemistry index were also performed. RESULTS: The podocyte counts in patients were significantly higher than controls. Podocytes counts positively correlated with PCX concentrations and the serum CysC. The podocyte count had higher diagnostic efficiency than PCX concentrations detected by ELISA and serum CysC. CONCLUSIONS: The podocyte count detected by our improved method had higher diagnostic efficiency than ELISA and serum CysC.
Assuntos
Glomerulonefrite/sangue , Glomerulonefrite/diagnóstico , Imuno-Histoquímica/métodos , Glomérulos Renais/patologia , Podócitos/citologia , Adulto , Nitrogênio da Ureia Sanguínea , Contagem de Células/métodos , Creatinina/sangue , Cistatina C/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Glomerulonefrite/patologia , Humanos , Masculino , Sialoglicoproteínas/urina , Ácido Úrico/sangue , Microglobulina beta-2/sangueRESUMO
The involvement of the glomerulus in the pathogenesis of cystinosis, caused by loss-of-function mutations in cystinosin (CTNS, 17p13), is a matter of controversy. Although patients with cystinosis demonstrate glomerular lesions and high-molecular-weight proteinuria starting from an early age, a mouse model of cystinosis develops only signs of proximal tubular dysfunction. Here we studied podocyte damage in patients with cystinosis by analyzing urinary podocyte excretion and by in vitro studies of podocytes deficient in cystinosin. Urine from patients with cystinosis presented a significantly higher amount of podocytes compared with controls. In culture, cystinotic podocytes accumulated cystine compatible with cystinosin deficiency. The expression of podocyte specific genes CD2AP, podocalyxin, and synaptopodin and of the WT1 protein was evident in all cell lines. Conditionally immortalized podocyte lines of 2 patients with different CTNS mutations had altered cytoskeleton, impaired cell adhesion sites, and increased individual cell motility. Moreover, these cells showed enhanced phosphorylation of both Akt1 and Akt2 (isoforms of protein kinase B). Inhibition of Akt by a specific inhibitor (Akti inhibitor 1/2) resulted in normalization of the hypermotile phenotype. Thus, our study extends the list of genetic disorders causing podocyte damage and provides the evidence of altered cell signaling cascades resulting in impaired cell adhesion and enhanced cell motility in cystinosis.
Assuntos
Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Movimento Celular , Cistinose/metabolismo , Podócitos/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adolescente , Sistemas de Transporte de Aminoácidos Neutros/deficiência , Sistemas de Transporte de Aminoácidos Neutros/genética , Estudos de Casos e Controles , Adesão Celular , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Criança , Pré-Escolar , Cistinose/genética , Cistinose/patologia , Cistinose/urina , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/metabolismo , Regulação para Baixo , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Mutação , Fenótipo , Fosforilação , Podócitos/efeitos dos fármacos , Podócitos/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sialoglicoproteínas/genética , Sialoglicoproteínas/metabolismo , Transdução de Sinais , Urina/citologia , Proteínas WT1/genética , Proteínas WT1/metabolismo , Adulto JovemRESUMO
BACKGROUND: Chemical induced nephrotoxicity is one of the main causes of acute kidney injury. The objective of this study was to determine the antioxidant effect of vitamin E against carbon tetrachloride induced tubulointerstitial and glomerular damage in the kidney of albino mice. METHODS: The study had been conducted on albino mice. The duration of study was for five weeks. A total of 35 animals were randomly divided into five groups A, B, C, D and E .The group A served as control group, group B was administered only with carbon tetrachloride (no vitamin E) and groups C, D and E received test drug (vitamin E) in doses of 1, 10 and 50mg/kg body weight respectively along with CCl4. The animals were dissected and kidneys were excised for microscopic study for possible histo-morphological effects. RESULTS: It was observed that carbon tetrachloride treated experimental groups developed tubulo-interstitial and glomerular changes as compared to control group A. The results suggested that these changes were significantly reduced in vitamin E treated groups especially in dose of 50 mg/kg body weight. CONCLUSIONS: This study reveals that tubulointerstitial and glomerular damage caused by carbon tetrachloride can be reduced by vitamin E in dose of 50 mg/kg body weight.
Assuntos
Antioxidantes/farmacologia , Tetracloreto de Carbono/toxicidade , Nefropatias/induzido quimicamente , Rim/efeitos dos fármacos , Vitamina E/farmacologia , Animais , Rim/patologia , Nefropatias/patologia , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/patologia , CamundongosRESUMO
Nephrotoxicity is defining as rapid deterioration in the kidney function due to toxic effect of medications and chemicals. There are various forms, and some drugs may affect renal function in more than one way. Nephrotoxins are substances displaying nephrotoxicity. Different mechanisms lead to nephrotoxicity, including renal tubular toxicity, inflammation, glomerular damage, crystal nephropathy, and thrombotic microangiopathy. The traditional markers of nephrotoxicity and renal dysfunction are blood urea and serum creatinine which are regarded as low sensitive in the detection of early renal damage. Thus, the detection of the initial renal injures required new biomarkers which are more sensitive and highly specific that gives an insight into the site of underlying renal damage. Kidney injury molecule-1, Cystatin C, and neutrophil gelatinase-associated lipocalin sera levels are more sensitive than blood urea and serum creatinine in the detection of acute kidney injury during nephrotoxicity.
RESUMO
PURPOSE OF REVIEW: Diabetic nephropathy (DN) is a progressive kidney disease caused by alterations in kidney architecture and function, and constitutes one of the leading causes of end-stage renal disease (ESRD). The purpose of this review is to summarize the state of the art of the DN-biomarker field with a focus on the new strategies that enhance the sensitivity of biomarkers to predict patients who will develop DN or are at risk of progressing to ESRD. OBJECTIVE: In this review, we provide a description of the pathophysiology of DN and propose a panel of novel putative biomarkers associated with DN pathophysiology that have been increasingly investigated for diagnosis, to predict disease progression or to provide efficient personal treatment. METHODS: We performed a review of the literature with PubMed and Google Scholar to collect baseline data about the pathophysiology of DN and biomarkers associated. We focused our research on new and emerging biomarkers of DN. KEY FINDINGS: In this review, we summarized the critical signaling pathways and biological processes involved in DN and highlighted the pathogenic mediators of this disease. We next proposed a large review of the major advances that have been made in identifying new biomarkers which are more sensitive and reliable compared with currently used biomarkers. This includes information about emergent biomarkers such as functional noncoding RNAs, microRNAs, long noncoding RNAs, exosomes, and microparticles. LIMITATIONS: Despite intensive strategies and constant investigation, no current single treatment has been able to reverse or at least mitigate the progression of DN, or reduce the morbidity and mortality associated with this disease. Major difficulties probably come from the renal disease being heterogeneous among the patients. IMPLICATIONS: Expanding the proteomics screening, including oxidative stress and inflammatory markers, along with metabolomics approaches may further improve the prognostic value and help in identifying the patients with diabetes who are at high risk of developing kidney diseases.
La néphropathie diabétique (ND) est une affection évolutive causée par des modifications dans la physionomie et la fonction des reins. Elle constitue l'une des principales causes d'insuffisance rénale terminale (IRT). L'objectif de cette revue est de faire état des plus récentes connaissances au sujet des biomarqueurs de la ND, en mettant l'accent sur les nouvelles stratégies qui augmentent la sensibilité des biomarqueurs à dépister les patients susceptibles de développer la ND ou qui courent le risque de voir leur état évoluer vers l'insuffisance rénale terminale. OBJECTIF DE LA REVUE: Dans cette revue, nous fournissons d'abord une description de la physiopathologie de la ND. Nous proposons ensuite un panel de nouveaux biomarqueurs putatifs associés à la physiopathologie de la ND, et qui ont de plus en plus été étudiés dans le but d'établir le diagnostic de la maladie, de prédire son évolution ou de fournir un traitement individuel efficace. MÉTHODOLOGIE: Nous avons procédé à une revue de la littérature sur PubMed et Google Scholar afin de recueillir des données de base au sujet de la physiopathologie de la ND ainsi que sur les biomarqueurs qui y sont associés. Nous avons concentré nos recherches sur les biomarqueurs nouvellement identifiés ou émergents. PRINCIPALES CONCLUSIONS: La revue fait un résumé des voies de signalisation essentielles et des processus biologiques impliqués dans l'évolution de la ND, en plus de mettre en évidence les médiateurs pathogènes de la maladie. Nous faisons également état des avancées majeures réalisées dans l'identification de nouveaux biomarqueurs plus sensibles et plus fiables que ceux qui sont utilisés à l'heure actuelle. Enfin, cette revue collige des renseignements au sujet des biomarqueurs émergents tels que les ARN non codants fonctionnels, les microARN, les longs ARN non codants, les exosomes et les microparticules. LIMITES DE LA REVUE: À ce jour, malgré des stratégies de plus en plus pointues et le fait que la recherche soit en constante progression, aucun traitement unique n'a réussi à inverser ou même à freiner l'évolution de la néphropathie diabétique, ni à réduire la morbidité et la mortalité associées à cette maladie. L'hétérogénéité des maladies rénales observée dans la population des personnes atteintes contribue probablement aux difficultés rencontrées. CONCLUSIONS: La généralisation du dépistage par la protéomique, notamment par la mesure du stress oxydatif et des marqueurs inflammatoires, ainsi que l'approche métabolomique pourraient contribuer à améliorer la valeur pronostique et aider à cibler les patients atteints de diabète qui courent un risque élevé de développer de l'insuffisance rénale.