RESUMO
Tubular-interstitial nephritis (TIN) is characterized by tubular cell damage and inflammatory lesions of kidneys. Baicalein (BAI) is a flavonoid compound found in the roots of Scutellaria baicalensis Georgi. The present study was undertaken to explore the anti-inflammatory and anti-oxidative effects of BAI on TIN patients and a lipopolysaccharide (LPS)-induced TIN cell model. The expression levels of interleukin-6 (IL-6), IL-10, and tumor necrosis factor α in serum samples of TIN patients and culture supernatants of renal proximal tubular epithelial cells (RPTECs) were evaluated using enzyme-linked immunosorbent assay. Creatinine clearance was calculated using the Cockcroft-Gault equation. Activities of malondialdehyde, superoxide dismutase, and glutathione peroxidase were also determined. Viability and apoptosis of RPTECs were measured using MTT assay and Guava Nexin assay, respectively. qRT-PCR was performed to determine the expressions of Bax, Bcl-2, nuclear factor kappa B (IκBα), and p65. Protein levels of Bax, Bcl-2, IκBα, p65, c-Jun N-terminal kinase, extracellular regulated protein kinases, and p38 were analyzed using western blotting. We found that BAI reduced inflammation and oxidative stress in vivo and in vitro. Moreover, BAI alleviated the LPS-induced RPTECs viability inhibition and apoptosis enhancement, as well as nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) activation. Phorbol ester, an activator of NF-κB, attenuated the effects of BAI on LPS-induced inflammatory cytokine expressions in RPTECs. In conclusion, BAI had anti-inflammatory and anti-oxidative effects on TIN patients and LPS-induced RPTECs by down-regulating NF-κB and MAPK pathways.
Assuntos
Anti-Inflamatórios/administração & dosagem , Antioxidantes/administração & dosagem , Flavanonas/administração & dosagem , NF-kappa B/metabolismo , Nefrite Intersticial/tratamento farmacológico , Adolescente , Adulto , Regulação para Baixo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lipopolissacarídeos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , NF-kappa B/efeitos dos fármacos , Nefrite Intersticial/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Adulto JovemRESUMO
Proteinuria is critical in the tubulointerstitial changes that ultimately lead to renal insufficiency. Increased protein filtration has direct toxic effects on tubular epithelial cells, leading to epithelial mesenchymal transition (EMT) to a myofibroblast phenotype. Angiotensin II and transforming growth factor (TGF)-ß1 are the main mediators of EMT. Calcitriol may exert a potential renoprotective effect by reducing the activity of the renin angiotensin system by suppressing renin gene expression and also by inhibiting the proinflammatory nuclear factor-κB pathway. The present study investigated the benefits of calcitriol treatment in a puromycin-induced proteinuric nephropathy model. Uninephrectomized adult male Wistar rats received intraperitoneal administration of a single dose of puromycin (100 mg/kg) or vehicle. After eight weeks, the animals were divided into two groups and received vehicle or calcitriol (0.5 µg/kg) for four weeks. The vehicle-treated, proteinuric rats developed progressive proteinuria and tubulointerstitial fibrosis after 12 weeks. Increased collagen deposition and fibrosis were significantly ameliorated by calcitriol treatment. Calcitriol was effective in preventing an increase in the EMT markers, α-smooth muscle actin and fibroblast-specific protein 1, reducing macrophage infiltration as evidenced by levels of ED-1. In addition, calcitriol increased the anti-inflammatory cytokine interleukin-10 and reduced the pro-oxidant p47 phox enzyme. These effects were paralleled by a reduction in TGF-ß/Smad3 expression. Calcitriol may have therapeutic potential in the proteinuric nephropathy model used in the present study by inhibiting the TGF-ß1 axis.
Assuntos
Calcitriol/farmacologia , Rim/efeitos dos fármacos , Nefrite Intersticial/tratamento farmacológico , Proteinúria/tratamento farmacológico , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Vitaminas/farmacologia , Actinas/genética , Actinas/metabolismo , Animais , Biomarcadores/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Modelos Animais de Doenças , Ectodisplasinas/genética , Ectodisplasinas/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fibrose , Expressão Gênica , Interleucina-10/agonistas , Interleucina-10/genética , Interleucina-10/metabolismo , Rim/metabolismo , Rim/patologia , Masculino , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Nefrectomia , Nefrite Intersticial/induzido quimicamente , Nefrite Intersticial/metabolismo , Nefrite Intersticial/patologia , Proteinúria/induzido quimicamente , Proteinúria/metabolismo , Proteinúria/patologia , Puromicina , Ratos , Ratos Wistar , Sistema Renina-Angiotensina/efeitos dos fármacos , Proteína Smad3/antagonistas & inibidores , Proteína Smad3/genética , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismoRESUMO
Macrophages play a special role in the onset of several diseases, including acute and chronic kidney injuries. In this sense, tubule interstitial nephritis (TIN) represents an underestimated insult, which can be triggered by different stimuli and, in the absence of a proper regulation, can lead to fibrosis deposition. Based on this perception, we evaluated the participation of macrophage recruitment in the development of TIN. Initially, we provided adenine-enriched food to WT and searched for macrophage presence and action in the kidney. Also, a group of animals were depleted of macrophages with the clodronate liposome while receiving adenine-enriched diet. We collected blood and renal tissue from these animals and renal function, inflammation, and fibrosis were evaluated. We observed higher expression of chemokines in the kidneys of adenine-fed mice and a substantial protection when macrophages were depleted. Then, we specifically investigated the role of some key chemokines, CCR5 and CCL3, in this TIN experimental model. Interestingly, CCR5 KO and CCL3 KO animals showed less renal dysfunction and a decreased proinflammatory profile. Furthermore, in those animals, there was less profibrotic signaling. In conclusion, we can suggest that macrophage infiltration is important for the onset of renal injury in the adenine-induced TIN.
Assuntos
Injúria Renal Aguda/metabolismo , Adenina/toxicidade , Quimiocina CCL3/metabolismo , Rim/metabolismo , Macrófagos/metabolismo , Receptores CCR5/metabolismo , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Animais , Quimiocina CCL3/genética , Citometria de Fluxo , Rim/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Nefrite Intersticial/metabolismo , Receptores CCR5/genéticaRESUMO
Adenine overload promotes intratubular crystal precipitation and interstitial nephritis. We showed recently that these abnormalities are strongly attenuated in mice knockout for Toll-like receptors-2, -4, MyD88, ASC, or caspase-1. We now investigated whether NF-κB activation also plays a pathogenic role in this model. Adult male Munich-Wistar rats were distributed among three groups: C (n = 17), receiving standard chow; ADE (n = 17), given adenine in the chow at 0.7% for 1 wk and 0.5% for 2 wk; and ADE + pyrrolidine dithiocarbamate (PDTC; n = 14), receiving adenine as above and the NF-κB inhibitor PDTC (120 mg·kg⻹·day⻹ in the drinking water). After 3 wk, widespread crystal deposition was seen in tubular lumina and in the renal interstitium, along with granuloma formation, collagen accumulation, intense tubulointerstitial proliferation, and increased interstitial expression of inflammatory mediators. Part of the crystals were segregated from tubular lumina by a newly formed cell layer and, at more advanced stages, appeared to be extruded to the interstitium. p65 nuclear translocation and IKK-α increased abundance indicated activation of the NF-κB system. PDTC treatment prevented p65 migration and normalized IKK-α, limited crystal shift to the interstitium, and strongly attenuated interstitial fibrosis/inflammation. These findings indicate that the complex inflammatory phenomena associated with this model depend, at least in part, on NF-κB activation, and suggest that the NF-κB system may become a therapeutic target in the treatment of chronic kidney disease.
Assuntos
Adenina/análogos & derivados , Mediadores da Inflamação/metabolismo , NF-kappa B/metabolismo , Nefrite Intersticial/etiologia , Nefroesclerose/etiologia , Pirrolidinas/uso terapêutico , Tiocarbamatos/uso terapêutico , Adenina/efeitos adversos , Animais , Modelos Animais de Doenças , Fibrose , Granuloma/etiologia , Mediadores da Inflamação/fisiologia , Rim/patologia , Masculino , NF-kappa B/antagonistas & inibidores , Nefrite Intersticial/metabolismo , Nefrite Intersticial/patologia , Nefroesclerose/metabolismo , Nefroesclerose/patologia , Ratos , Ratos WistarRESUMO
PURPOSE OF REVIEW: Impairment of the pressure natriuresis relationship is a central event in the pathogenesis of hypertension. Renal tubulointerstitial inflammation results in salt-sensitive hypertension and, until recently, the changes in pressure natriuresis induced by renal inflammation received little attention. RECENT FINDINGS: Oxidative stress and increased intrarenal angiotensin II activity, in association with rarefaction and loss of peritubular vascular network, may be involved in the inflammation-induced blunting of the natriuresis resulting from increments in renal perfusion pressure. SUMMARY: Here, we review the mechanisms for the impairment in pressure natriuresis resulting from renal tubulointerstitial inflammation in reference to the normal physiologic mechanisms involved in this response.
Assuntos
Hipertensão/fisiopatologia , Natriurese/fisiologia , Nefrite Intersticial/fisiopatologia , Angiotensina II/metabolismo , Humanos , Túbulos Renais/irrigação sanguínea , Microvasos/fisiopatologia , Nefrite Intersticial/metabolismo , Estresse Oxidativo , Cloreto de Sódio na Dieta/efeitos adversosRESUMO
BACKGROUND/AIMS: The effects of cigarette smoke (CS) on cyclosporine (CsA)-induced nephrotoxicity are poorly studied. This study aims to assess the effects of previous exposure to CS on CsA nephrotoxicity. METHODS: Rats were either exposed to CS or sham (S) procedures for 10 min twice a day for 20 weeks. From the 16th to the 20th week, they received a low-salt diet. Beginning with the 17th week, they were given 2.5 mg/day CsA or vehicle (VH) for 3 weeks. The final groups were VH/CS, CsA/CS, VH/S, and CsA/S. On day 141, glomerular filtration rate (GFR), renal blood flow (RBF), renal vascular resistance (RVR), tubulointerstitial fibrosis, and CsA blood levels were measured and immunohistochemistry was analyzed for renal α-smooth muscle actin (SMA), nitrotyrosine, and vimentin. RESULTS: CsA decrease in GFR was enhanced by CS exposure. CsA associated with CS induced higher periglomerular α-SMA and renal nitrotyrosine expression. CsA decreased RBF, but increased RVR, tubulointerstitial fibrosis, and α-SMA and renal vimentin expression. These changes and the CsA blood levels were not affected by CS exposure. CONCLUSION: CS aggravated the CsA-induced impairment of GFR and CS associated with CsA caused the development of periglomerular structural lesions and oxidative stress in a rat model of CsA nephrotoxicity.
Assuntos
Ciclosporina/toxicidade , Imunossupressores/toxicidade , Nefrite Intersticial/induzido quimicamente , Fumar/efeitos adversos , Actinas/metabolismo , Animais , Ciclosporina/sangue , Modelos Animais de Doenças , Sinergismo Farmacológico , Fibrose/induzido quimicamente , Fibrose/metabolismo , Fibrose/patologia , Taxa de Filtração Glomerular/efeitos dos fármacos , Hematócrito , Hemodinâmica/efeitos dos fármacos , Hemodinâmica/fisiologia , Humanos , Imunossupressores/sangue , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Masculino , Nefrite Intersticial/metabolismo , Nefrite Intersticial/patologia , Ratos , Ratos Wistar , Tirosina/análogos & derivados , Tirosina/metabolismo , Vimentina/metabolismoRESUMO
Tubule-interstitial nephritis (TIN) results in decreased renal function and interstitial inflammation, which ultimately leads to fibrosis. Excessive adenine intake can cause TIN because xanthine dehydrogenase (XDH) can convert this purine into an insoluble compound, which precipitates in the tubuli. Innate immune sensors, such as Toll-like receptors (TLR) and inflammasome complex, play a crucial role in the initiation of inflammation. The aim of this study was to evaluate the roles of TLR-2 and -4, Myd88 and inflammasome complex in an experimental model of TIN. Here, we show that wild-type (WT) mice fed adenine-enriched food exhibited significant renal dysfunction and enhanced cellular infiltration accompanied by collagen deposition. They also presented higher gene and protein expression of pro-inflammatory cytokines. In contrast, TLR-2, -4, MyD88, ASC and Caspase-1 KO mice showed renoprotection associated with expression of inflammatory molecules at levels comparable to controls. Furthermore, treatment of WT animals with allopurinol, an XDH inhibitor, led to reduced levels of uric acid, oxidative stress, collagen deposition and a downregulation of the NF-kB signaling pathway. We concluded that MyD88 signaling and inflammasome participate in the development of TIN. Furthermore, inhibition of XDH seems to be a promising way to therapeutically target the developing inflammatory process.
Assuntos
Inflamassomos/metabolismo , Túbulos Renais/patologia , Fator 88 de Diferenciação Mieloide/metabolismo , Nefrite Intersticial/metabolismo , Nefrite Intersticial/patologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Adenina/administração & dosagem , Adenina/farmacologia , Alopurinol/farmacologia , Alopurinol/uso terapêutico , Animais , Dieta , Progressão da Doença , Inflamassomos/efeitos dos fármacos , Inflamação/patologia , Túbulos Renais/metabolismo , Camundongos , Camundongos Knockout , Nefrite Intersticial/tratamento farmacológico , Nefrite Intersticial/prevenção & controle , Transdução de Sinais/efeitos dos fármacos , Xantina Desidrogenase/antagonistas & inibidores , Xantina Desidrogenase/metabolismoRESUMO
There is compelling evidence that interstitial inflammation plays a central role in the loss of renal function in chronic renal disease. The combined effects of interstitial inflammation, oxidative stress and local angiotensin II activity result in the disruption of glomerulus-tubule continuity, the development of pathogenic hypoxia, the generation of myofibroblasts and fibrosis, and the impairment of the protective autoregulation of glomerular blood flow that leads to glomerulosclerosis. The association between proteinuria and progression of chronic kidney disease is firmly established. Proximal tubular cells (PTC) exposed to high concentration of proteins produce proinflammatory and profibrotic factors. The activation of nuclear factor κB and the signal transducer and activator of transcription results in the upregulation of a variety of cytokines and chemokines, overexpression of adhesion molecules and interstitial infiltration of inflammatory cells. Fibrosis is promoted by release of transforming growth factor ß, which induces myofibroblast formation and collagen deposition. Finally, the participation of vitamin D3 deficiency in the development of tubulointerstitial fibrosis is reviewed. The molecule 1,25-(OH)(2)D(3) modulates PTC proliferation, suppresses fibroblast activation and matrix production, reduces epithelial mesenchymal transition and downregulates the genes of the renin-angiotensin system, which are critical steps in the development of a scarred kidney.
Assuntos
Falência Renal Crônica/patologia , Túbulos Renais/patologia , Nefrite Intersticial/patologia , Animais , Progressão da Doença , Humanos , Inflamação/complicações , Inflamação/metabolismo , Inflamação/patologia , Falência Renal Crônica/etiologia , Falência Renal Crônica/metabolismo , Túbulos Renais/metabolismo , Nefrite Intersticial/complicações , Nefrite Intersticial/metabolismo , Estresse Oxidativo/fisiologia , Proteinúria/metabolismo , Proteinúria/patologiaRESUMO
The adolescent nephronophthisis (NPH3) is a variant of the nephronophthisis. In Venezuela, one to three patients have been registered each year, all of them belonging to the same family tree. The objective of this study was to evaluate the function of the proximal convoluted tubule in NPHP3 carriers; using the beta2M as biological marker. Eight carriers, 7 heterozygotes and 1 homozygote, with normal renal function were compared with a 10 healthy subjects (control group). Serum beta2 microglobulin (beta2M), urinary beta2M, the quotient urinary beta2M/urinary creatinine and the beta2M fractional excretion were determinated. The filtered beta2M and the percentage of reabsortion were calculated. We observed an increase in the plasmatic concentration of beta2M but not related with a decrease of the glomerular filtration. The urinary beta2M, the beta2M/urinary creatinine relation and the fractional excretion of beta2M were normal. The filtered load of beta2M was elevated without increase in the excretion or percentage of reabsortion. We conclude that in our group of NPH3 carriers, functional changes in the proximal convoluted tubule, when measured by urinary excretion of beta2M, were absent. This finding suggests the existence of other mechanism of uptake or degradation of the substance in the proximal convoluted tubule, which have yet to be elucidated.
Assuntos
Rim/metabolismo , Nefrite Intersticial/genética , Nefrite Intersticial/metabolismo , Microglobulina beta-2/metabolismo , Feminino , Heterozigoto , Humanos , Rim/fisiopatologia , Masculino , Nefrite Intersticial/fisiopatologia , LinhagemRESUMO
BACKGROUND: The present study was performed to explore the effect of exogenous infusions of atrial natriuretic peptide (ANP) on the early inflammatory response during acute sodium overload in normal rats. METHODS: Sprague Dawley rats were exposed to acute sodium overload (Na 1.5 M). Nonhypotensive doses of ANP (1 and 5 microg x kg(-1) x h(-1)) were infused simultaneously with sodium or after sodium infusion in order to evaluate prevention or reversion of the inflammatory response, respectively. We determined inflammation markers in renal tissue by immunohistochemistry. RESULTS: Creatinine clearance was not reduced in any case. Sodium tubular reabsorption increased after sodium overload (334.3 +/- 18.7 vs. control 209.6 +/- 27.0 mEq x min(-1), p < 0.05) without changes in mean arterial pressure. This increase was prevented (228.9 +/- 26.4; p < 0.05) and reversed (231.5 +/- 13.9; p < 0.05) by ANP-5 microg x kg(-1) x h(-1). Sodium overload increased the expression of: RANTES (38.4.3 +/- 0.8 vs. 2.9 +/- 0.6%, p < 0.001), transforming-growth-factor-beta(1) (35.3 +/- 1.0 vs. 5.0 +/- 0.7%, p < 0.001), alpha-smooth muscle actin (15.6 +/- 0.7 vs. 3.1 +/- 0.3%, p < 0.001), NF-kappaB (9.4 +/- 1.3 to 2.2 +/- 0.5 cells/mm(2), p < 0.001), HIF-1alpha (38.2 +/- 1.7 to 8.4 +/- 0.8 cells/mm(2), p < 0.001) and angiotensin II (35.9 +/- 1.3 to 8.2 +/- 0.5%, p < 0.001). ANP-5 microg x kg(-1) x h(-1) prevented and reversed inflammation: RANTES (9.2 +/- 0.5 and 6.9 +/- 0.7, p < 0.001); transforming growth factor-beta(1) (13.2 +/- 0.7 and 10.2 +/- 0.5, p < 0.001) and alpha-smooth muscle actin (4.1 +/- 0.4 and 5.2 +/- 0.4, p < 0.001). Both prevention and reversion by ANP were associated with downregulation of NF-kappaB (3.2 +/- 0.4 and 2.8 +/- 0.5, p < 0.001) and angiotensin II (8.2 +/- 0.5 and 9.1 +/- 0.7, p < 0.001) and diminished hypoxia evaluated through HIF-1alpha expression (8.4 +/- 0.8 and 8.8 +/- 0.7, p < 0.001). CONCLUSION: Our study provides evidence supporting a protective role of ANP in both prevention and reversion of renal inflammation in rats with acute sodium overload.