FLAVIA GOMES MACHADO
Projetos de Pesquisa
Unidades Organizacionais
LIM/16 - Laboratório de Fisiopatologia Renal, Hospital das Clínicas, Faculdade de Medicina
11 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 11
- NLRP3 inflammasome inhibition ameliorates tubulointerstitial injury in the remnant kidney model(2018) FORESTO-NETO, Orestes; AVILA, Victor Ferreira; ARIAS, Simone Costa Alarcon; ZAMBOM, Fernanda Florencia Fregnan; REMPEL, Lisienny Campoli Tono; FAUSTINO, Viviane Dias; MACHADO, Flavia Gomes; MALHEIROS, Denise Maria Avancini Costa; ABENSUR, Hugo; CAMARA, Niels Olsen Saraiva; ZATZ, Roberto; FUJIHARA, Clarice KazueRecent studies suggest that NLRP3 inflammasome activation is involved in the pathogenesis of chronic kidney disease (CKD). Allopurinol (ALLO) inhibits xanthine oxidase (XOD) activity, and, consequently, reduces the production of uric acid (UA) and reactive oxygen species (ROS), both of which can activate the NLRP3 pathway. Thus, ALLO can contribute to slow the progression of CKD. We investigated whether inhibition of XOD by ALLO reduces NLRP3 activation and renal injury in the 5/6 renal ablation (Nx) model. Adult male Munich-Wistar rats underwent Nx and were subdivided into the following two groups: Nx, receiving vehicle only, and Nx + ALLO, Nx rats given ALLO, 36 mg/Kg/day in drinking water. Rats undergoing sham operation were studied as controls (C). Sixty days after surgery, Nx rats exhibited marked albuminuria, creatinine retention, and hypertension, as well as glomerulosclerosis, tubular injury, and cortical interstitial expansion/inflammation/fibrosis. Such changes were accompanied by increased XOD activity and UA renal levels, associated with augmented heme oxigenase-1 and reduced superoxide dismutase-2 renal contents. Both the NF-kappa B and NLRP3 signaling pathways were activated in Nx. ALLO normalized both XOD activity and the parameters of oxidative stress. ALLO also attenuated hypertension and promoted selective tubulointerstitial protection, reducing urinary NGAL and cortical interstitial injury/inflammation. ALLO reduced renal NLRP3 activation, without interfering with the NF-kappa B pathway. These observations indicate that the tubulointerstitial antiinflammatory and antifibrotic effects of ALLO in the Nx model involve inhibition of the NLRP3 pathway, and reinforce the view that ALLO can contribute to arrest or slow the progression of CKD.
- Effects of losartan, in monotherapy or in association with hydrochlorothiazide, in chronic nephropathy resulting from losartan treatment during lactation(2011) FANELLI, C.; FERNANDES, B. H. V.; MACHADO, F. G.; OKABE, C.; MALHEIROS, D. M. A. C.; FUJIHARA, C. K.; ZATZ, R.Fanelli C, Fernandes BH, Machado FG, Okabe C, Malheiros DM, Fujihara CK, Zatz R. Effects of losartan, in monotherapy or in association with hydrochlorothiazide, in chronic nephropathy resulting from losartan treatment during lactation. Am J Physiol Renal Physiol 301: F580-F587, 2011. First published June 8, 2011; doi:10.1152/ajprenal.00042.2011.-We recently standardized a model (L(Lact)) of severe chronic kidney disease based on impaired nephrogenesis by suppression of angiotensin II activity during lactation (Machado FG, Poppi EP, Fanelli C, Malheiros DM, Zatz R, Fujihara CK. Am J Physiol Renal Physiol 294: F1345-F1353, 2008). In this new study of the L(Lact) model, we sought to gain further insight into renal injury mechanisms associated with this model and to verify whether the renoprotection obtained with the association of the angiotensin II receptor blocker losartan (L) and hydrochlorothiazide (H), which arrested renal injury in the remnant kidney model, would provide similar renoprotection. Twenty Munich-Wistar dams, each nursing six pups, were divided into control, untreated, and L(Lact) groups, given losartan (L; 250 mg.kg(-1).day(-1)) until weaning. The male LLact offspring remained untreated until 7 mo of age, when renal functional and structural parameters were studied in 17 of them, used as pretreatment control (L(Lact)Pre), and followed no further. The remaining rats were then divided among groups L(Lact) + V, untreated; L(Lact) + L, given L (50 mg.kg(-1).day(-1)) now as a therapy; L(Lact) + H, given H (6 mg.kg(-1).day(-1)); and L(Lact) + LH, given L and H. All parameters were reassessed 3 mo later in these groups and in age-matched controls. At this time, L(Lact) rats exhibited hypertension, severe albuminuria, glomerular damage, marked interstitial expansion/inflammation, enhanced cell proliferation, myofibroblast infiltration, and creatinine retention. L monotherapy normalized albuminuria and prevented hypertension and the progression of renal injury, inflammation, and myofibroblast infiltration. In contrast to the remnant model, the LH combination promoted only slight additional renoprotection, perhaps because of a limited tendency to retain sodium in L(Lact) rats.
- Regression of Albuminuria and Hypertension and Arrest of Severe Renal Injury by a Losartan-Hydrochlorothiazide Association in a Model of Very Advanced Nephropathy(2013) ARIAS, Simone Costa Alarcon; VALENTE, Carla Perez; MACHADO, Flavia Gomes; FANELLI, Camilla; ORIGASSA, Clarice Silvia Taemi; BRITO, Thales de; CAMARA, Niels Olsen Saraiva; MALHEIROS, Denise Maria Avancini Costa; ZATZ, Roberto; FUJIHARA, Clarice KazueTreatments that effectively prevent chronic kidney disease (CKD) when initiated early often yield disappointing results when started at more advanced phases. We examined the long-term evolution of renal injury in the 5/6 nephrectomy model (Nx) and the effect of an association between an AT-1 receptor blocker, losartan (L), and hydrochlorothiazide (H), shown previously to be effective when started one month after Nx. Adult male Munich-Wistar rats underwent Nx, being divided into four groups: Nx+V, no treatment; Nx+L, receiving L monotherapy; Nx+LH, receiving the L+H association (LH), and Nx+AHHz, treated with the calcium channel blocker, amlodipine, the vascular relaxant, hydralazine, and H. This latter group served to assess the effect of lowering blood pressure (BP). Rats undergoing sham nephrectomy (S) were also studied. In a first protocol, treatments were initiated 60 days after Nx, when CKD is at a relatively early stage. In a second protocol, treatments were started 120 days after Nx, when glomerulosclerosis and interstitial fibrosis are already advanced. In both protocols, L treatment promoted only partial renoprotection, whereas LH brought BP, albuminuria, tubulointerstitial cell proliferation and plasma aldosterone below pretreatment levels, and completely detained progression of renal injury. Despite normalizing BP, the AHHz association failed to prevent renal damage, indicating that the renoprotective effect of LH was not due to a systemic hemodynamic action. These findings are inconsistent with the contention that thiazides are innocuous in advanced CKD. In Nx, LH promotes effective renoprotection even at advanced stages by mechanisms that may involve anti-inflammatory and intrarenal hemodynamic effects, but seem not to require BP normalization.
- Chronic VEGF Blockade Worsens Glomerular Injury in the Remnant Kidney Model(2012) MACHADO, Flavia G.; KURIKI, Patricia Semedo; FUJIHARA, Clarice K.; FANELLI, Camilla; ARIAS, Simone C. A.; MALHEIROS, Denise M. A. C.; CAMARA, Niels O. S.; ZATZ, RobertoVEGF inhibition can promote renal vascular and parenchymal injury, causing proteinuria, hypertension and thrombotic microangiopathy. The mechanisms underlying these side effects are unclear. We investigated the renal effects of the administration, during 45 days, of sunitinib (Su), a VEGF receptor inhibitor, to rats with 5/6 renal ablation (Nx). Adult male Munich-Wistar rats were distributed among groups S+V, sham-operated rats receiving vehicle only; S+Su, S rats given Su, 4 mg/kg/day; Nx+V, Nx rats receiving V; and Nx+Su, Nx rats receiving Su. Su caused no change in Group S. Seven and 45 days after renal ablation, renal cortical interstitium was expanded, in association with rarefaction of peritubular capillaries. Su did not worsen hypertension, proteinuria or interstitial expansion, nor did it affect capillary rarefaction, suggesting little angiogenic activity in this model. Nx animals exhibited glomerulosclerosis (GS), which was aggravated by Su. This effect could not be explained by podocyte damage, nor could it be ascribed to tuft hypertrophy or hyperplasia. GS may have derived from organization of capillary microthrombi, frequently observed in Group Nx+Su. Treatment with Su did not reduce the fractional glomerular endothelial area, suggesting functional rather than structural cell injury. Chronic VEGF inhibition has little effect on normal rats, but can affect glomerular endothelium when renal damage is already present.
- Simultaneous activation of innate and adaptive immunity participates in the development of renal injury in a model of heavy proteinuria(2018) FAUSTINO, Viviane Dias; ARIAS, Simone Costa Alarcon; AVILA, Victor Ferreira; FORESTO-NETO, Orestes; ZAMBOM, Fernanda Florencia Fregnan; MACHADO, Flavia Gomes; REIS, Luciene Machado dos; MARIA, Denise; VOLPINI, Rildo Aparecido; CAMARA, Niels Olsen Saraiva; ZATZ, Roberto; FUJIHARA, Clarice KazueProtein overload of proximal tubular cells (PTCs) can promote interstitial injury by unclear mechanisms that may involve activation of innate immunity. We investigated whether prolonged exposure of tubular cells to high protein concentrations stimulates innate immunity, triggering progressive interstitial inflammation and renal injury, and whether specific inhibition of innate or adaptive immunity would provide renoprotection in an established model of massive proteinuria, adriamycin nephropathy (ADR). Adult male Munich-Wistar rats received a single dose of ADR (5 mg/kg, iv), being followed for 2, 4, or 20 weeks. Massive albuminuria was associated with early activation of both the NE-kappa B and NLRP3 innate immunity pathways, whose intensity correlated strongly with the density of lymphocyte infiltration. In addition, ADR rats exhibited clear signs of renal oxidative stress. Twenty weeks after ADR administration, marked interstitial fibrosis, glomerulosclerosis, and renal functional loss were observed. Administration of mycophenolate mofetil (MMF), 10 mg/kg/day, prevented activation of both innate and adaptive immunity, as well as renal oxidative stress and renal fibrosis. Moreover, MMF treatment was associated with shifting of M from the M1 to the M2 phenotype. In cultivated NRK52-E cells, excess albumin increased the protein content of Toll-like receptor (TLR) 4 (TLR4), NLRP3, MCP-1, IL6, IL-1 beta Caspase-1, alpha-actin, and collagen-1. Silencing of TLR4 and/or NLRP3 mRNA abrogated this proinflammatory/profibrotic behavior. Simultaneous activation of innate and adaptive immunity may be key to the development of renal injury in heavy proteinuric disease. Inhibition of specific components of innate and/or adaptive immunity may be the basis for future strategies to prevent chronic kidney disease (CKD) in this setting.
- Resistance training downregulates macrophages infiltration in the kidney of 5/6 nephrectomized rats(2018) MORAES, Milton Rocha; ROSA, Thiago Santos; SOUZA, Michel Kendy; NEVES, Rodrigo Vanerson Passos; BACURAU, Reury Frank Pereira; PASSOS, Clevia Santos; CENEDEZE, Marcos Antonio; PASSOS, Michelle Tiveron; MACHADO, Flavia Gomes; PACHECO-SILVA FILHO, Alvaro; CAMARA, Niels Olsen SaraivaIntroduction: Chronic kidney disease (CKD) is considered a significant world health problem with elevated mortality rates. Patients with CKD are restricted to mild physical activity, present chronic inflammatory state and loss of muscle strength. Currently, the influence of resistance exercise (RE) on the progression of renal disease has not being fully elucidated. Purpose: To evaluate the effects of RE on the progression of CKD in a remnant kidney model (5/6Nx) in rats. Methods: Eight-week-old Wistar rats were submitted to 5/6 nephrectomy and were divided into four groups: Sham sedentary (Sham SD); Sham RE (Sham RE); 5/6Nx SD and 5/6Nx RE. The animals were trained for 8 weeks in a vertical climbing ladder for 3 days per week, on non-consecutive days. Results: As expected, 5/6Nx SD group presented a markedly loss of renal function, increased plasma inflammatory cytokines and increased oxidative stress with a reduced activity of nitric oxide. The higher macrophage infiltration and fibrosis confirmed these conditions. RE attenuated systolic blood pressure and renal function decrease and also improved serum lipid parameters in 5/6 Nx animals. It was evident the increase of muscle strength and mass in the trained groups while the sedentary group showed reduced muscle weight and strength compared to Sham SD. Conclusions: RE implemented following 5/6Nx retard the progression of chronic kidney injury while simultaneously allowed the maintenance of skeletal muscle strength.
- Innate And Adaptive Immunity are Progressively Activated in Parallel with Renal Injury in the 5/6 Renal Ablation Model(2017) FANELLI, Camilla; ARIAS, Simone C. A.; MACHADO, Flavia G.; OKUMA, Jessica K.; MALHEIROS, Denise M. A. C.; AZEVEDO, Hatylas; MOREIRA-FILHO, Carlos A.; CAMARA, Niels O. S.; FUJIHARA, Clarice K.; ZATZ, RobertoThe mechanisms triggering renal inflammation in chronic kidney disease (CKD) are unclear. We performed a detailed analysis of the time course of innate and adaptive immunity activation in the 5/6 renal ablation (Nx) model. Munich-Wistar rats undergoing Nx were studied 15, 60 and 120 days after ablation. Hypertension, albuminuria, creatinine retention, interstitial expansion and infiltration by macrophages and T-lymphocytes were already evident 15 days after Nx. PCR-array was used to screen for altered gene expression, whereas gene and protein expressions of TLR4, CASP1, IL-1 beta and NLRP3 were individually assessed. Tlr4, Tlr5, Lbp, Nlrp3, Casp1, Irf7 and Il1b were already upregulated 15 days after Nx, while activation of Tlr2, Tlr7, Tlr9, Nod2, Tnf and Il6 was seen after 60 days post-ablation. The number of genes related to innate or adaptive immunity grew steadily with time. These observations indicate that parallel activation of innate and adaptive immunity antecedes glomerular injury and involves a growing number of intricate signaling pathways, helping to explain the difficulty in detaining renal injury in Nx as CKD advances, and, stressing the need for early treatment. Additionally, these findings may contribute to the search of therapeutic targets specific for advanced phases of CKD.
- Programmed hypertension in rats treated with a NF-kappa B inhibitor during nephrogenesis: renal mechanisms(2011) CANALE, Daniele; RODRIGUES, Mariliza V.; FERREIRA, Daniele N.; MACHADO, Flavia G.; VERAS, Mariana M.; MALHEIROS, Denise M. A. C.; KRIEGER, Jose E.; FUJIHARA, Clarice K.; VENTURINI, Gabriela; ZATZ, RobertoSuppression of the renin-angiotensin system (RAS) during murine lactation causes progressive renal injury, indicating a physiological action of angiotensin II on nephrogenesis. The nuclear factor NF-kappa B system is one of the main intracellular mediators of angiotensin II. We investigated whether inhibition of this system with pyrrolidine dithiocarbamate (PDTC) during rat nephrogenesis would lead to similar hypertension and renal injury as observed with RAS suppressors. Immediately after delivery, 32 Munich-Wistar dams, each nursing 6 male pups, were divided into 2 groups: C, untreated, and PDTC, receiving PDTC, 280 mg kg(-1) day(-1) orally, during 21 days. After weaning, the offspring were followed until 10 months of age without treatment. Adult rats that received neonatal PDTC exhibited stable hypertension and myocardial injury, without albuminuria. To gain additional insight into this process, the renal expression of RAS components and sodium transporters were determined by quantitative real-time PCR (qRT-PCR) at 3 and 10 months of life. Renal renin and angiotensinogen were upregulated at 3 and downregulated at 10 months of age, suggesting a role for early local RAS activation. Likewise, there was early upregulation of the proximal sodium/glucose and sodium/bicarbonate transporters, which abated later in life, suggesting that additional factors sustained hypertension in the long run. The conclusions drawn from the findings were as follows: (1) an intact NF-jB system during nephrogenesis may be essential to normal renal and cardiovascular function in adult life; (2) neonatal PDTC represents a new model of hypertension, lacking overt structural injury or functional impairment of the kidneys; and (3) hypertension in this model seems associated with early temporary activation of renal RAS and sodium transporters. Hypertension Research (2011) 34, 693-700; doi: 10.1038/hr. 2011.4; published online 17 February 2011
conferenceObject Influence of dietary phosphorus in the regulation of Sodium phosphate cotransporters in uremic rats(2014) ANITELI, Tatiana; MACHADO, Flavia; REIS, Luciene dos; DOMINGUEZ, Wagner; CASTELUCCI, Patricia; JORGETTI, Vanda- NF-kappa B activation mediates crystal translocation and interstitial inflammation in adenine overload nephropathy(2013) OKABE, Cristiene; BORGES, Raquel Lerner; ALMEIDA, Danilo Candido de; FANELLI, Camilla; BARLETTE, Grasiela Pedreira; MACHADO, Flavia Gomes; ARIAS, Simone Costa Alarcon; MALHEIROS, Denise Maria Avancini Costa; CAMARA, Niels Olsen Saraiva; ZATZ, Roberto; FUJIHARA, Clarice KazueAdenine 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-kappa B 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-kappa B inhibitor PDTC (120 mg.kg(-1).day(-1) 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-alpha increased abundance indicated activation of the NF-kappa B system. PDTC treatment prevented p65 migration and normalized IKK-alpha, 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-kappa B activation, and suggest that the NF-kappa B system may become a therapeutic target in the treatment of chronic kidney disease.