ANTONIO CARLOS SEGURO
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/12 - Laboratório de Pesquisa Básica em Doenças Renais, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/12 - Laboratório de Pesquisa Básica em Doenças Renais, Hospital das Clínicas, Faculdade de Medicina - Líder
36 resultados
Resultados de Busca
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- Cathelicidin protects mice from Rhabdomyolysis-induced Acute Kidney Injury(2021) SILVA, Beatriz Helena Cermaria Soares da; ARIGA, Suely Kubo; BARBEIRO, Hermes Vieira; VOLPINI, Rildo Aparecido; BARBEIRO, Denise Frediani; SEGURO, Antonio Carlos; SILVA, Fabiano Pinheiro daBackground: Cathelicidins are ancient and well-conserved antimicrobial peptides (AMPs) with intriguing immunomodulatory properties in both infectious and non-infectious inflammatory diseases. In addition to direct antimicrobial activity, cathelicidins also participate in several signaling pathways inducing both pro-inflammatory and anti-inflammatory effects. Acute kidney injury (AKI) is common in critically ill patients and is associated with high mortality and morbidity. Rhabdomyolysis is a major trigger of AKI. Objectives: Here, we investigated the role of cathelicidins in non-infectious Acute kidney Injury (AKI). Method: Using an experimental model of rhabdomyolysis, we induced AKI in wild-type and cathelicidin-related AMP knockout (CRAMP(-/-)) mice. Results: We previously demonstrated that CRAMP(-/-) mice, as opposed wild-type mice, are protected from AKI during sepsis induced by cecal ligation and puncture. Conversely, in the current study, we show that CRAMP(-/-) mice are more susceptible to the rhabdomyolysis model of AKI. A more in-depth investigation of wild-type and CRAMP(-/-) mice revealed important differences in the levels of several inflammatory mediators. Conclusion: Cathelicidins can induce a varied and even opposing repertoire of immune-inflammatory responses depending on the subjacent disease and the cellular context.
- Vitamin D Deficiency Aggravates Chronic Kidney Disease Progression after Ischemic Acute Kidney Injury(2014) GONCALVES, Janaina Garcia; BRAGANCA, Ana Carolina de; CANALE, Daniele; SHIMIZU, Maria Heloisa Massola; SANCHES, Talita Rojas; MOYSES, Rosa Maria Affonso; ANDRADE, Lucia; SEGURO, Antonio Carlos; VOLPINI, Rildo AparecidoBackground: Despite a significant improvement in the management of chronic kidney disease (CKD), its incidence and prevalence has been increasing over the years. Progressive renal fibrosis is present in CKD and involves the participation of several cytokines, including Transforming growth factor-beta 1 (TGF-beta 1). Besides cardiovascular diseases and infections, several studies show that Vitamin D status has been considered as a non-traditional risk factor for the progression of CKD. Given the importance of vitamin D in the maintenance of essential physiological functions, we studied the events involved in the chronic kidney disease progression in rats submitted to ischemia/reperfusion injury under vitamin D deficiency (VDD). Methods: Rats were randomized into four groups: Control; VDD; ischemia/reperfusion injury (IRI); and VDD+IRI. At the 62 day after sham or IRI surgery, we measured inulin clearance, biochemical variables and hemodynamic parameters. In kidney tissue, we performed immunoblotting to quantify expression of Klotho, TGF-beta, and vitamin D receptor (VDR); gene expression to evaluate renin, angiotensinogen, and angiotensin-converting enzyme; and immunohistochemical staining for ED1 (macrophages), type IV collagen, fibronectin, vimentin, and alpha-smooth mucle actin. Histomorphometric studies were performed to evaluate fractional interstitial area. Results: IRI animals presented renal hypertrophy, increased levels of mean blood pressure and plasma PTH. Furthermore, expansion of the interstitial area, increased infiltration of ED1 cells, increased expression of collagen IV, fibronectin, vimentin and alpha-actin, and reduced expression of Klotho protein were observed. VDD deficiency contributed to increased levels of plasma PTH as well as for important chronic tubulointerstitial changes (fibrosis, inflammatory infiltration, tubular dilation and atrophy), increased expression of TGF-beta 1 and decreased expression of VDR and Klotho protein observed in VDD+IRI animals. Conclusion: Through inflammatory pathways and involvement of TGF-beta 1 growth factor, VDD could be considered as an aggravating factor for tubulointerstitial damage and fibrosis progression following acute kidney injury induced by ischemia/reperfusion.
- Vitamin D Deficiency Aggravates the Renal Features of Moderate Chronic Kidney Disease in 5/6 Nephrectomized Rats(2018) BRAGANCA, Ana Carolina de; CANALE, Daniele; GONCALVES, Janaina Garcia; SHIMIZU, Maria Heloisa Massola; SEGURO, Antonio Carlos; VOLPINI, Rildo AparecidoThe pathogenesis of chronic kidney disease (CKD) involves a very complex interaction between hemodynamic and inflammatory processes, leading to glomerular/vascular sclerosis, and fibrosis formation with subsequent evolution to end-stage of renal disease. Despite efforts to minimize the progression of CKD, its incidence and prevalence continue to increase. Besides cardiovascular diseases and infections, several studies demonstrate that vitamin D status could be considered as a non-traditional risk factor for the progression of CKD. Therefore, we investigated the effects of vitamin D deficiency (VDD) in the course of moderate CKD in 5/6 nephrectomized rats (Nx). Adult male Wistar rats underwent Sham surgery or Nx and were subdivided into the following four groups: Sham, receiving standard diet (Sham); Sham VDD, receiving vitamin D-free diet (VDD); Nx, receiving standard diet (Nx); and VDD+Nx, receiving vitamin D-free diet (VDD+Nx). Sham or Nx surgeries were performed 30 days after standard or vitamin D-free diets administration. After validation of vitamin D depletion, we considered only Nx and VDD+Nx groups for the following studies. Sixty days after surgeries, VDD+Nx rats exhibited hypertension, a greater decline in renal function and plasma FGF-23 levels, renal hypertrophy, as well as higher plasma levels of PTH and aldosterone. In addition, those animals presented more significant chronic tubulointerstitial changes (cortical interstitial expansion/inflammation/fibrosis), higher expression of collagen IV, fibronectin and alpha-smooth muscle actin, and lower expressions of JG12 and M2 macrophages. Also, VDD+Nx rats had greater infiltration of inflammatory cells (M1 macrophages and T-cells). Such changes were accompanied by higher expression of TGF-beta 1 and angiotensinogen and decreased expression of VDR and Klotho protein. Our observations indicate that vitamin D deficiency impairs the renal function and worsens the renovascular and morphological changes, aggravating the features of moderate CKD in 5/6 nephrectomized rats.
- Vitamin D deficiency aggravates ischemic acute kidney injury in rats(2015) BRAGANCA, Ana Carolina de; VOLPINI, Rildo A.; CANALE, Daniele; GONCALVES, Janaina G.; SHIMIZU, Maria Heloisa M.; SANCHES, Talita R.; SEGURO, Antonio C.; ANDRADE, LuciaVitamin D deficiency (VDD) increases the risk of death in hospitalized patients. Renal ischemia/reperfusion injury (IRI) induces acute kidney injury (AKI), which activates cell cycle inhibitors, including p21, a cyclindependent kinase inhibitor and genomic target of 25-hydroxyvitamin D, which is in turn a potent immunomodulator with antiproliferative effects. In this study, we assess the impact of VDD in renal IRI. Wistar rats were divided into groups, each evaluated for 30 days: control (receiving a standard diet); VDD (receiving a vitamin D-free diet); IRI (receiving a standard diet and subjected to 45-min bilateral renal ischemia on day 28); and VDD + IRI (receiving a vitamin D-free diet and subjected to 45-min bilateral renal ischemia on day 28). At 48 h after IRI, animals were euthanized; blood, urine, and kidney tissue samples were collected. Compared with IRI rats, VDD + IRI rats showed a more severe decrease in glomerular filtration rate, greater urinary protein excretion, a higher kidney/body weight ratio and lower renal aquaporin 2 expression, as well as greater morphological damage, characterized by increased interstitial area and tubular necrosis. Our results suggest that the severity of tubular damage in IRI may be associated with downregulation of vitamin D receptors and p21. VDD increases renal inflammation, cell proliferation and cell injury in ischemic AKI.
- Apolipoprotein A-I mimetic peptide 4F attenuates kidney injury, heart injury, and endothelial dysfunction in sepsis(2014) MOREIRA, Roberto S.; IRIGOYEN, Maria; SANCHES, Talita R.; VOLPINI, Rildo A.; CAMARA, Niels O. S.; MALHEIROS, Denise M.; SHIMIZU, Maria H. M.; SEGURO, Antonio C.; ANDRADE, LuciaKidney injury, heart injury, and cytokine-induced vascular hyperpermeability are associated with high rates of morbidity and mortality in sepsis. Although the mechanism remains unknown, apolipoprotein A-I (apoA-I) mimetic peptide 4F reduces inflammation and protects HDL levels, which are reduced in sepsis. We hypothesized that 4F also protects kidneys and hearts in a rat model of cecal ligation and puncture (CLP). We divided Wistar rats into groups: sham-operated (control), CLP, and CLP+4F (10 mg/kg body wt ip, 6 h after CLP). At 24 h post-CLP, we evaluated cardiac function, mean arterial pressure (MAP), heart rate (HR), baroreflex sensitivity, total cholesterol, LDL, HDL, serum cytokines, and inulin clearance. We performed immunoblotting for protein regulators of vascular permeability (Slit2 and Robo4) and endothelial nitric oxide synthase (eNOS) in kidney tissue. We evaluated heart mitochondria with electron microscopy. Although there was no difference in MAP, the HR was significantly higher in CLP rats than in control and CLP+4F rats. In CLP+4F rats, baroreflex sensitivity and cardiac function were completely protected from the effects of CLP, as was glomerular filtration; heart mitochondria morphology was improved; sepsis-induced changes in serum cholesterol, LDL, HDL, and apoA-I were less common; all cytokines were lower than in CLP rats; and expression of Slit2, Robo4, and eNOS was completely restored. Administration of 4F inhibits inflammatory responses and strengthens the vascular barrier, protecting kidneys and hearts in an HDL-dependent manner. To determine the extent of the protective effect of 4F, further studies are needed.
- Vitamin D deficiency is a potential risk factor for contrast-induced nephropathy(2015) LUCHI, Weverton M.; SHIMIZU, Maria Heloisa M.; CANALE, Daniele; GOIS, Pedro Henrique F.; BRAGANCA, Ana Carolina de; VOLPINI, Rildo A.; GIRARDI, Adriana C. C.; SEGURO, Antonio C.Vitamin D deficiency (VDD) is widespread in the general population. Iodinated (IC) or gadolinium-based contrast media (Gd) may decrease renal function in high-risk patients. This study tested the hypothesis that VDD is a predisposing factor for IC-or Gd-induced nephrotoxicity. To this end, male Wistar rats were fed standard (SD) or vitamin D-free diet for 30 days. IC (diatrizoate), Gd (gadoterate meglumine), or 0.9% saline was then administered intravenously and six groups were obtained as the following: SD plus 0.9% saline (Sham-SD), SD plus IC (SD + IC), SD plus Gd (SD + Gd), vitamin D-free diet for 30 days plus 0.9% saline (Sham-VDD30), vitamin D-free diet for 30 days plus IC (VDD30 + IC), and vitamin D-free diet for 30 days plus Gd (VDD30 + Gd). Renal hemodynamics, redox status, histological, and immunoblot analysis were evaluated 48 h after contrast media (CM) or vehicle infusion. VDD rats showed lower levels of total serum 25-hydroxyvitamin D [25(OH)D], similar plasma calcium and phosphorus concentration, and higher renal renin and angiotensinogen protein expression compared with rats fed SD. IC or Gd infusion did not affect inulin clearance-based estimated glomerular filtration rate (GFR) in rats fed SD but significantly decreased GFR in rats fed vitamin D-free diet. Both CM increased renal angiotensinogen, and the interaction between VDD and CM triggered lower renal endothelial nitric oxide synthase abundance and higher renal thiobarbituric acid reactive substances-to-glutathione ratio (an index of oxidative stress) on VDD30 + IC and VDD30 + Gd groups. Conversely, worsening of renal function was not accompanied by abnormalities on kidney structure. Additionally, rats on a VDD for 60 days displayed a greater fall in GFR after CM administration. Collectively, our findings suggest that VDD is a potential risk factor for IC-or Gd-induced nephrotoxicity most likely due to imbalance in intrarenal vasoactive substances and oxidative stress.
- N-acetylcysteine protects against star fruit-induced acute kidney injury(2017) SHIMIZU, Maria Heloisa Massola; GOIS, Pedro Henrique Franca; VOLPINI, Rildo Aparecido; CANALE, Daniele; LUCHI, Weverton Machado; FROEDER, Leila; HEILBERG, Ita Pfeferman; SEGURO, Antonio CarlosBackground: Star fruit (SF) is a popular fruit, commonly cultivated in many tropical countries, that contains large amount of oxalate. Acute oxalate nephropathy and direct renal tubular damage through release of free radicals are the main mechanisms involved in SF-induced acute kidney injury (AKI). The aim of this study was to evaluate the protective effect of N-acetylcysteine (NAC) on SF-induced nephrotoxicity due to its potent antioxidant effect. Materials and methods: Male Wistar rats received SF juice (4 mL/100 g body weight) by gavage after a 12 h fasting and water deprivation. Fasting and water deprivation continued for 6 h thereafter to warrant juice absorption. Thereafter, animals were allocated to three experimental groups: SF (n = 6): received tap water; SF+NAC (n = 6): received NAC (4.8 g/L) in drinking water for 48 h after gavage; and Sham (n = 6): no interventions. After 48 h, inulin clearance studies were performed to determine glomerular filtration rate. In a second series of experiment, rats were housed in metabolic cages for additional assessments. Results: SF rats showed markedly reduced inulin clearance associated with hyperoxaluria, renal tubular damage, increased oxidative stress and inflammation. NAC treatment ameliorated all these alterations. Under polarized light microscopy, SF rats exhibited intense calcium oxalate birefringence crystals deposition, dilation of renal tubules and tubular epithelial degeneration, which were attenuate by NAC therapy. Conclusions: Our data show that therapeutic NAC attenuates renal dysfunction in a model of acute oxalate nephropathy following SF ingestion by reducing oxidative stress, oxaluria, and inflammation. This might represent a novel indication of NAC for the treatment of SF-induced AKI.
- Treatment with beta-blocker nebivolol ameliorates oxidative stress and endothelial dysfunction in tenofovir-induced nephrotoxicity in rats(2022) NASCIMENTO, Mariana Moura; BERNARDO, Desiree Rita Denelle; BRAGANCA, Ana Carolina de; SHIMIZU, Maria Heloisa Massola; SEGURO, Antonio Carlos; VOLPINI, Rildo Aparecido; CANALE, DanieleBackgroundTenofovir disoproxil fumarate (TDF), a widely prescribed component in antiretroviral regimens, has been associated with nephrotoxicity. Nebivolol is a third generation selective beta-1 adrenergic receptor blocker and may protect renal structure and function through the suppression of oxidative stress and enhancement of nitric oxide (NO) synthesis. We aimed to investigate whether nebivolol could be an effective therapeutic strategy to mitigate tenofovir-induced nephrotoxicity. MethodsWe allocated Wistar rats to four groups: control (C), received a standard diet for 30 days; NBV, received a standard diet for 30 days added with nebivolol (100 mg/kg food) in the last 15 days; TDF, received a standard diet added with tenofovir (300 mg/kg food) for 30 days; and TDF+NBV, received a standard diet added with tenofovir for 30 days and nebivolol in the last 15 days. ResultsLong-term exposure to tenofovir led to impaired renal function, induced hypertension, endothelial dysfunction and oxidative stress. Nebivolol treatment partially recovered glomerular filtration rate, improved renal injury, normalized blood pressure and attenuated renal vasoconstriction. Administration of nebivolol contributed to reductions in asymmetric dimethylarginine (ADMA) levels as well as increases in endothelial nitric oxide sintase (eNOS) accompanied by renin-angiotensin-aldosterone system downregulation and decreases in macrophage and T-cells infiltrate. Furthermore, nebivolol was responsible for the maintenance of the adequate balance of thiobarbituric acid reactive substances (TBARS) and glutathione (GSH) levels and it was associated with reductions in NADPH oxidase (NOX) subunits. ConclusionNebivolol holds multifaceted actions that promote an advantageous option to slow the progression of kidney injury in tenofovir-induced nephrotoxicity.
- N-acetylcysteine attenuates renal alterations induced by senescence in the rat (vol 48, pg 298, 2013)(2013) SHIMIZU, M. H.; VOLPINI, R. A.; BRAGANCA, A. C. de; CAMPOS, R.; CANALE, D.; SANCHES, T. R.; ANDRADE, L.; SEGURO, A. C.
conferenceObject VITAMIN D DEFICIENCY AGGRAVATES TENOFOVIR INDUCED METABOLIC SYNDROME AND RENAL FAILURE(2013) CANALE, Daniele; BRAGANCA, Ana Carolina de; GONCALVES, Janana; SHIMIZU, Maria Helosa M.; VOLPINI, Rildo A.; ANDRADE, Lucia; SEGURO, Antonio CarlosIntroduction and Aims:Vitamin D deficiency (VDD) is highly prevalent among HIV-infected individuals. Tenofovir disoproxil fumarate (TDF), a widely used component of antiretroviral regimens for HIV treatment, has been associated with comorbidities, some of which have been attributed to renal toxicity and metabolic syndrome. The aim of the study was to investigate the effect of VDD on TDF treated rats. Methods:Wistar rats were randomly divided into four groups: control (C, n = 9), receiving a standard diet for 60 days; VDD (n = 6), receiving a free-vitamin D diet for 60 days; TDF (n = 9), receiving a standard diet for 60 days with the addition of TDF (50 mg/kg food) for the last 30 days; and VDD+TDF (n = 7) received a free-vitamin D diet for 60 days with the addition of TDF (50 mg/kg food) for the last 30 days. We measured inulin clearance (GFR, mL/min/100g); blood pressure (BP, mmHg), renal blood flow and calculated renal vascular resistance (RVR, mmHg/mL/min); serum levels of 25-hydroxyvitamin D (25(OH)D, ng/mL), cholesterol (mg/dL) and triglycerides (mg/dL); urinary sodium excretion (UVNa,mEq/24h). In renal tissue, we immunoblotted for angiotensin II (AII), endothelial nitric oxide synthase (eNOS) and vitamin D receptor (VDR). Data are expressed as mean ± SEM. Results:Vitamin D levels were similar in C (15.4±1 ng/mL) and TDF (14.8±1.3 ng/mL) groups and <1.5 ng/mL in VDD groups. Body weight, water intake and food ingestion were not different among the 4 groups. Treatment with TDF led to impaired renal function, hypertension, higher RVR and dyslipidemia. Administration of TDF also increased protein expression of AII and VDR. Association of TDF and VDD exacerbates TDF nephrotoxicity, as well as metabolic syndrome. Furthermore, VDD+TDF group showed urinary sodium retention. The increased VDR protein expression in TDF groups may represent a compensatory effect to decrease renal injury. Conclusions:VDD aggravates renovascular effects and TDF-induced renal failure at least in part due to the involvement of renin-angiotensin-aldosterone system. Therefore, the assessment of vitamin D is important in HIV patients receiving TDF.