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
8 resultados
Resultados de Busca
Agora exibindo 1 - 8 de 8
- 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.
bookPart Ácido úrico e rim(2014) GOIS, Pedro Henrique França; LUCHI, Weverton Machado; SEGURO, Antonio CarlosconferenceObject N-acetylcystein Reduces Lipid Peroxidation and Advanced Glycation Related to Prevention of Macrophage Endoplasmic Reticulum Stress Induced by Albumin Isolated from Rats With Chronic Kidney Disease(2014) MACHADO, Juliana T.; IBORRA, Rodrigo T.; FUSCO, Fernanda B.; CASTILHO, Gabriela; PINTO, Raphael S.; MACHADO-LIMA, Adriana; NAKANDAKARE, Edna R.; SHIMIZU, Maria Heloisa M.; SEGURO, Antonio Carlos; CATANOZI, Sergio; PASSARELLI, Marisa- 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.
conferenceObject TUBULOGLOMERULAR EVALUATION IN VISCERAL LEISHMANIASIS BEFORE AND AFTER TREATMENT WITH PENTAVALENT ANTIMONIAL(2014) OLIVEIRA, Michelle J. C.; SILVA JUNIOR, Geraldo; SAMPAIO, Aline M.; MONTENEGRO, Barbara; ALVES, Marilia P.; HENN, Guilherme A. L.; ROCHA, Hermano A. L.; MENESES, Gdayllon C.; MARTINS, Alice M. C.; SANCHES, Talita R.; ANDRADE, Lucia C.; SEGURO, Antonio C.; LIBORIO, Alexandre B.; DAHER, Elizabeth F.- N-acetyl-cysteine is associated to renal function improvement in patients with nephropathic cystinosis(2014) GUIMARAES, Luciana Pache de Faria; SEGURO, Antonio Carlos; SHIMIZU, Maria Heloisa Mazzola; NERI, Leticia Aparecida Lopes; SUMITA, Nairo Massakasu; BRAGANCA, Ana Carolina de; VOLPINI, Rildo Aparecido; SANCHES, Talita Rojas Cunha; FONSECA, Fernanda Andrade Macaferri da; MOREIRA FILHO, Carlos Alberto; VAISBICH, Maria HelenaNephropathic cystinosis is an autosomal recessive systemic severe disease characterized by intralysosomal cystine storage. Cysteamine is an essential component of treatment. There is solid evidence that cystine accumulation itself is not responsible for all abnormalities in cystinosis; there is also a deficiency of glutathione in the cytosol. Patients with cystinosis can be more susceptible to oxidative stress. The patient cohort comprised 23 cystinosis patients (16 males) aged < 18 years (mean age 8.0 +/- 3.6 years) with chronic kidney disease class I-IV with good adherence to treatment, including cysteamine. Oxidative stress was evaluated based on the levels of serum thiobarbituric acid-reactive substances (TBARS), and renal function was evaluated based on serum creatinine and cystatin C levels and creatinine clearance (Schwartz formula). N-Acetylcysteine (NAC), an antioxidant drug was given to all patients for 3 months (T1) at 25 mg/kg/day divided in three doses per day. The measured values at just before the initiation of NAC treatment (T0) served as the control for each patient. Median serum TBARS levels at T0 and T1 were 6.92 (range 3.3-29.0) and 1.7 (0.6-7.2) nmol/mL, respectively (p < 0.0001). In terms of renal function at T0 and T1, serum creatinine levels (1.1 +/- 0.5 vs. 0.9 +/- 0.5 mg/dL, respectively; p < 0.0001), creatinine clearance (69.7 +/- 32.2 vs. T1 = 78.5 +/- 33.9 mL/min/1.73 m(2), respectively; p = 0.006), and cystatin c level (1.33 +/- 0.53 vs. 1.15 +/- 0.54 mg/l, respectively; p = 0.0057) were all significantly different at these two time points. Serum creatinine measurements at 6 (T -6) and 3 months (T -3) before NAC initiation and at 3 (T +3) and 6 months (T +6) after NAC had been withdrawn were also evaluated. During the 3-month period that our 23 cystinosis patients were treated with NAC, oxidative stress was reduced and renal function significantly improved. No side-effects were detected. Larger and controlled studies are needed to confirm these findings.
- Vitamin D Deficiency Aggravates Nephrotoxicity, Hypertension and Dyslipidemia Caused by Tenofovir: Role of Oxidative Stress and Renin-Angiotensin System(2014) CANALE, Daniele; BRAGANCA, Ana Carolina de; GONCALVES, Janaina Garcia; SHIMIZU, Maria Heloisa Massola; SANCHES, Talita Rojas; ANDRADE, Lucia; VOLPINI, Rildo Aparecido; SEGURO, Antonio CarlosVitamin D deficiency (VDD) is prevalent among HIV-infected individuals. Vitamin D has been associated with renal and cardiovascular diseases because of its effects on oxidative stress, lipid metabolism and renin-angiotensin-aldosterone system (RAAS). Tenofovir disoproxil fumarate (TDF), a widely used component of antiretroviral regimens for HIV treatment, can induce renal injury. The aim of this study was to investigate the effects of VDD on TDF-induced nephrotoxicity. Wistar rats were divided into four groups: control, receiving a standard diet for 60 days; VDD, receiving a vitamin D-free diet for 60 days; TDF, receiving a standard diet for 60 days with the addition of TDF (50 mg/kg food) for the last 30 days; and VDD+ TDF receiving a vitamin D-free diet for 60 days with the addition of TDF for the last 30 days. TDF led to impaired renal function, hyperphosphaturia, hypophosphatemia, hypertension and increased renal vascular resistance due to downregulation of the sodium-phosphorus cotransporter and upregulation of angiotensin II and AT1 receptor. TDF also increased oxidative stress, as evidenced by higher TBARS and lower GSH levels, and induced dyslipidemia. Association of TDF and VDD aggravated renovascular effects and TDF-induced nephrotoxicity due to changes in the redox state and involvement of RAAS.
- N-acetylcysteine prevents endoplasmic reticulum stress elicited in macrophages by serum albumin drawn from chronic kidney disease rats and selectively affects lipid transporters, ABCA-1 and ABCG-1(2014) MACHADO, Juliana T.; IBORRA, Rodrigo T.; FUSCO, Fernanda B.; CASTILHO, Gabriela; PINTO, Raphael S.; MACHADO-LIMA, Adriana; NAKANDAKARE, Edna R.; SEGURO, Antonio C.; SHIMIZU, Maria H.; CATANOZI, Sergio; PASSARELLI, MarisaIn chronic kidney disease (CKD) nontraditional risk factors, such as oxidative stress and advanced glycation end products (AGE) contribute to cardiovascular disease. Particularly, disturbances in reverse cholesterol transport favor the development of atherosclerosis. We analyzed the influence of N-acetylcysteine (NAC) in CKD rats on plasma concentration of lipid peroxides (TBARS) and AGE and on the impact of serum albumin in the development of macrophage endoplasmic reticulum stress (ERS) and cholesterol efflux, namely apo A-I and HDL2-mediated cholesterol removal and ABCA-1 and ABCG-1 protein level. CKD was induced by 5/6 nephrectomy in 2-month old male Wistar rats. Controls (Sham) were false operated. Animals were treated or not with NAC (600 mg/L of water). After 60 days serum albumin was isolated by FPLC and purified by alcoholic extraction. J774 macrophages were incubated with serum albumin (1 mg/mL; 18 h) from all groups, and the expression of ERS markers (protein disulfide isomerase - PDI, Grp78 and Grp94), ABCA-1 and ABCG-1 determined by immunoblot. HDL2 or apo A-I were used for cholesterol efflux assays. Protein and lipid composition of total HDL from Sham and CKD was determined and these particles tested on their abilities to accept cell cholesterol. Comparisons were done by one-way ANOVA and Newman Keuls post test. After 60 days of CKD, body weight was 10% lower in CKD compared to Sham (p < 0.01). This was prevented by NAC. Urea, creatinine, total cholesterol (TC), triglycerides (TG) (mg/dL), proteinuria (mg/24 h) (Sham, n = 31; Sham + NAC, n = 20; CKD, n = 74; CKD + NAC, n = 32), total AGE and pentosidine (n = 8; fluorescence arbitrary unit) and TBARS (n = 7; nmoL/mL) were higher in CKD (122 +/- 8; 0.9 +/- 0.07; 151 +/- 6; 83 +/- 4; 46 +/- 2.5; 32,620 +/- 673; 16,700 +/- 1,370; 6.6 +/- 0.5, respectively) and in CKD + NAC (91.4 +/- 5; 0.6 +/- 0.02; 126 +/- 7.5; 73 +/- 6; 51 +/- 3.5; 24,720 +/- 1,114; 10,080 +/- 748; 4.5 +/- 0.5, respectively) in comparison to Sham (41 +/- 0.9; 0.4 +/- 0.03; 76 +/- 2.7; 51.5 +/- 3; 14 +/- 0.9; 21,750 +/- 960; 5,314 +/- 129; 2.0 +/- 0.2, respectively; p < 0.001) and Sham + NAC (40 +/- 0.9; 0.3 +/- 0.02; 76 +/- 2.6; 68 +/- 4; 18.4 +/- 1.5; 20,040 +/- 700; 5,050 +/- 267; 1.8 +/- 0.2, respectively; p < 0.001). TC, urea, creatinine, total AGE, pentosidine and TBARS were respectively, 17%, 25%, 33%, 24%, 40% and 28% (p < 0.01) lower in CKD + NAC, than in CKD. Glycemia was higher in Sham + NAC (107 +/- 4.6) and CKD + NAC (107 +/- 2.6) than in Sham (96 +/- 1.8; p < 0.05) and CKD (98 +/- 1.6; p < 0.01), respectively. In macrophages (n = 6), CKD albumin increased PDI (3 and 6 times, p < 0.01) and Grp94 (66% and 80%, p < 0.01) in comparison to Sham and CKD + NAC-albumin treated cells, respectively. ABCA-1 expression was lower (87% and 70%, p < 0.001) in macrophage treated with Sham + NAC and CKD albumin respectively in comparison to Sham albumin; ABCG-1 was higher (4 and 7 times, p < 0.001) in macrophages treated with Sham + NAC and CKD + NAC albumin, respectively in comparison to Sham and CKD albumin. Apo A-I mediated cholesterol efflux was lower (59% and 70%, p < 0.0001) in macrophage treated with Sham + NAC and CKD albumin respectively in comparison to Sham albumin, however, the HDL2 mediated cholesterol efflux was higher (54% and 25%, p < 0. 0001) in macrophage treated with Sham + NAC albumin, in comparison to Sham and CKD + NAC albumin, respectively. CKD-HDL was enriched in total protein and lipids compared to Sham-HDL but preserved its capacity to remove cholesterol from macrophages. NAC reduces plasma lipid peroxidation and AGE and abrogates ERS induced by CKD-albumin. Despite diminishing ABCA-1, NAC increases ABCG-1 that counteracts the reduction in apo A-I-mediated cholesterol efflux. NAC may contribute to attenuate the deleterious effects of CKD-albumin on lipid accumulation in macrophages helping to prevent atherogenesis in CKD.