Therapeutic potential of human induced pluripotent stem cells and renal progenitor cells in experimental chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is a global public health problem. Cell therapy using pluripotent stem cells represents an attractive therapeutic approach for the treatment of CKD. METHODS: We transplanted mitomycin C (MMC)-treated human induced pluripotent stem cells (hiPSCs) and renal progenitor cells (RPCs) into a CKD rat model system. The RPC and hiPSC cells were characterized by immunofluorescence and qRT-PCR. Untreated 5/6 nephrectomized rats were compared to CKD animals receiving the same amount of MMC-treated hiPSCs or RPCs. Renal function, histology, and immunohistochemistry were evaluated 45 days post-surgery. RESULTS: We successfully generated hiPSCs from peripheral blood and differentiated them into RPCs expressing renal progenitor genes (PAX2, WT1, SIX2, and SALL1) and podocyte-related genes (SYNPO, NPHS1). RPCs also exhibited reduced OCT4 expression, confirming the loss of pluripotency. After cell transplantation into CKD rats, the body weight change was significantly increased in both hiPSC and RPC groups, in comparison with the control group. Creatinine clearance (CCr) was preserved only in the hiPSC group. Similarly, the number of macrophages in the kidneys of the hiPSC group reached a statistically significant reduction, when compared to control rats. Both treatments reduced positive staining for the marker α-smooth muscle actin. Histological features showed decreased tubulointerstitial damage (interstitial fibrosis and tubular atrophy) as well as a reduction in glomerulosclerosis in both iPSC and RPC groups. CONCLUSIONS: In conclusion, we describe that both MMC-treated hiPSCs and RPCs exert beneficial effects in attenuating CKD progression. Both cell types were equally efficient to reduce histological damage and weight loss caused by CKD. hiPSCs seem to be more efficient than RPCs, possibly due to a paracrine effect triggered by hiPSCs. These results demonstrate that the use of MMC-treated hiPSCs and RPCs improves clinical and histological CKD parameters, avoided tumor formation, and therefore may be a promising cell therapy strategy for CKD.

Does protein supplementation and exercise interfere with renal function and structure? / A suplementação de proteína e o exercício interferem na função e estrutura renal? / ¿la suplementación de proteínas y el ejercicio interfieren en la función y estructura renal?

ABSTRACT Introduction: During physical activity, the body diverts blood to essential areas such as skeletal muscle, reducing the supply to non-essential areas such as the kidney. Whey protein is one of the most widely used supplements in gyms. Objectives: To evaluate renal function and renal structure in rats submitted to physical exercise with and without the use of protein supplementation. Methods: The protein used was Whey Hydro PRO 2 - Probiotica®. It was administered orally (by gavage), diluted in mineral water (1.8 g/kg of body weight, shortly after swimming training). The rats were divided into four groups: rats with exercise (Exc), rats without exercise (ñExc), rats with exercise and with protein supplementation (Prot/Exc) and rats without exercise and with protein supplementation (Prot/ñExc). The training consisted of swimming for 30 minutes, using load equivalent to 2% of body weight, five times a week for a total of 10 weeks. The protein was administered by gavage, once daily, immediately after the training. Results: A reduced glomerular filtration rate was observed in the animals of the Exc group compared to those of the Prot/Exc group. Plasma creatinine values were similar between the groups submitted to exercise and those not submitted to exercise. Plasma sodium and the sodium excretion fraction were lower in the Prot/Exc group compared to the Exc group. Urinary excretion was similar between groups. Histological analysis: Significant hydropic degeneration was observed in the animals that received protein supplementation and submitted to exercise. Conclusion: These results show that exercise associated with protein supplementation (2g/day/kg) leads to changes in the tubular mechanisms of sodium adjustments and structural changes in the renal parenchyma. Level of evidence II; Therapeutic studies - Investigation the results of treatment.

RESUMO Introdução: Durante a atividade física o corpo faz remanejamento sanguíneo para áreas essenciais como a musculatura esquelética, reduzindo o suprimento em áreas não essenciais como o rim. O whey protein (proteína do soro do leite) é um dos suplementos mais usados nas academias. Objetivos: Avaliar a função e a estrutura renal em ratos submetidos ao exercício físico sem e com o uso da suplementação de proteína. Métodos: A proteína usada foi Whey Hydro PRO 2 - Probiótica®, sendo administrada por via oral (gavagem), diluída em água mineral (1,8 g/kg de peso corporal logo após o treino de natação). Os ratos foram divididos em quatro grupos: ratos com exercício (Exc), ratos sem exercício (ñExc), ratos com exercício e com suplementação alimentar de proteína (Prot/Exc) e ratos sem exercício e com suplementação alimentar de proteína (Prot/ñExc). O treinamento consistia em natação por 30 minutos, com utilização de carga, equivalente a 2% do peso corporal, 5 vezes por semana em um total de 10 semanas. A proteína foi administrada por gavagem, uma vez ao dia e logo depois do treino. Resultados: Observou-se queda da filtração glomerular renal nos animais do grupo Exc vs. Prot/Exc. Os valores de creatinina plasmática foram semelhantes entre os grupos que praticaram o exercício vs. os que não praticaram. Para o sódio plasmático e a fração de excreção de sódio, os valores foram menores no grupo Prot/Exc quando comparados com o grupo Exc. A excreção urinária de ureia foi semelhante entre os grupos. Análise histológica: Observou-se degeneração hidrópica significativa nos animais que receberam a suplementação de proteína e realizaram o exercício. Conclusão: Esses resultados mostram que o exercício em conjunto com a suplementação de proteína (2 g/dia/Kg), determina alterações nos mecanismos tubulares de ajustes do sódio e alterações estruturais no parênquima renal. Nível de evidência II; Estudos terapêuticos - Investigação dos resultados do tratamento.

RESUMEN Introducción: Durante la actividad física el cuerpo hace reubicación sanguínea hacia áreas esenciales como la musculatura esquelética, reduciendo el suministro en áreas no esenciales como el riñón. La whey protein (proteína del suero de la leche) es uno de los suplementos más usados en los gimnasios. Objetivos: Evaluar la función y la estructura renal en ratones sometidos al ejercicio físico sin y con el uso de la suplementación de proteína. Métodos: La proteína utilizada fue Whey Hydro PRO 2 - Probiótica® siendo administrada vía oral (gavaje), diluida en agua mineral (1,8 g/kg de peso corporal luego después del entrenamiento de natación). Los ratones fueron divididos en cuatro grupos: ratones con ejercicio (Exc), ratones sin ejercicio (ñExc), ratones con ejercicio y con suplementación alimentaria de proteína (Prot/Exc) y ratones sin ejercicio y con suplementación alimenticia de proteína (Prot/ñExc). El entrenamiento consistía en natación por 30 minutos, con uso de carga, equivalente al 2% del peso corporal, 5 veces por semana en un total de 10 semanas. La proteína fue administrada por gavaje, una vez al día y luego después del entrenamiento. Resultados: Se observó caída de la filtración glomerular renal en los animales del grupo Exc vs Prot/Exc. Los valores de creatinina plasmática fueron semejantes entre los grupos que practicaron el ejercicio vs los no practicaron. Para el sodio plasmático y la fracción de excreción de sodio, los valores fueron menores en el grupo Prot/Exc cuando comparados con el Exc. La excreción urinaria de urea fue semejante entre los grupos. Análisis histológico: Se observó degeneración hidrópica significativa en los animales que recibieron la suplementación de proteínas y no realizaron el ejercicio. Conclusión: Estos resultados muestran que el ejercicio en conjunto con la suplementación de proteína (2 g/día/Kg), determina alteraciones en los mecanismos tubulares de ajustes del sodio y alteraciones estructurales en el parénquima renal. Nivel de evidencia II; Estudios terapéuticos - Investigación de los resultados del tratamiento.

Prior intake of Brazil nuts attenuates renal injury induced by ischemia and reperfusion.

INTRODUCTION: Ischemia-reperfusion (IR) injury results from inflammation and oxidative stress, among other factors. Because of its anti-inflammatory and antioxidant properties, the Brazil nut (BN) might attenuate IR renal injury. OBJECTIVE: The aim of the present study was to investigate whether the intake of BN prevents or reduces IR kidney injury and inflammation, improving renal function and decreasing oxidative stress. METHODS: Male Wistar rats were distributed into six groups (N=6/group): SHAM (control), SHAM treated with 75 or 150 mg of BN, IR, and IR treated with 75 or 150 mg of BN. The IR procedure consisted of right nephrectomy and occlusion of the left renal artery with a non-traumatic vascular clamp for 30 min. BN was given daily and individually for 7 days before surgery (SHAM or IR) and maintained until animal sacrifice (48h after surgery). We evaluated the following parameters: plasma creatinine, urea, and phosphorus; proteinuria, urinary output, and creatinine clearance; plasmatic TBARS and TEAC; kidney expression of iNOS and nitrotyrosine, and macrophage influx. RESULTS: Pre-treatment with 75 mg of BN attenuated IR-induced renal changes, with elevation of creatinine clearance and urinary output, reducing proteinuria, urea, and plasmatic phosphorus as well as reducing kidney expression of iNOS, nitrotyrosine, and macrophage influx. CONCLUSION: Low intake of BN prior to IR-induced kidney injury improves renal function by inhibition of macrophage infiltration and oxidative stress.

Prior intake of Brazil nuts attenuates renal injury induced by ischemia and reperfusion / A ingestão prévia de castanha-do-brasil atenua a lesão renal induzida por isquemia e reperfusão

ABSTRACT Introduction: Ischemia-reperfusion (IR) injury results from inflammation and oxidative stress, among other factors. Because of its anti-inflammatory and antioxidant properties, the Brazil nut (BN) might attenuate IR renal injury. Objective: The aim of the present study was to investigate whether the intake of BN prevents or reduces IR kidney injury and inflammation, improving renal function and decreasing oxidative stress. Methods: Male Wistar rats were distributed into six groups (N=6/group): SHAM (control), SHAM treated with 75 or 150 mg of BN, IR, and IR treated with 75 or 150 mg of BN. The IR procedure consisted of right nephrectomy and occlusion of the left renal artery with a non-traumatic vascular clamp for 30 min. BN was given daily and individually for 7 days before surgery (SHAM or IR) and maintained until animal sacrifice (48h after surgery). We evaluated the following parameters: plasma creatinine, urea, and phosphorus; proteinuria, urinary output, and creatinine clearance; plasmatic TBARS and TEAC; kidney expression of iNOS and nitrotyrosine, and macrophage influx. Results: Pre-treatment with 75 mg of BN attenuated IR-induced renal changes, with elevation of creatinine clearance and urinary output, reducing proteinuria, urea, and plasmatic phosphorus as well as reducing kidney expression of iNOS, nitrotyrosine, and macrophage influx. Conclusion: Low intake of BN prior to IR-induced kidney injury improves renal function by inhibition of macrophage infiltration and oxidative stress.

RESUMO Introdução: a lesão por isquemia-reperfusão (IR) resulta, entre outros fatores, de inflamação e estresse oxidativo. Devido às suas propriedades anti-inflamatórias e antioxidantes, a castanha-do-brasil (BN) pode atenuar a lesão renal causada por IR. Objetivo: O objetivo foi investigar se a ingestão prévia de BN reduz a lesão e a inflamação renal causadas por IR, melhorando a função renal e o estresse oxidativo. Métodos: Ratos Wistar machos foram distribuídos em seis grupos (N=6/grupo): SHAM (controle), SHAM tratado com 75 ou 150 mg de BN, IR, e IR tratado com 75 ou 150 mg de BN. O procedimento de IR consistiu na nefrectomia à direita e oclusão da artéria renal esquerda por 30 minutos. A castanha foi administrada diariamente e individualmente por sete dias antes da cirurgia (SHAM ou IR), e mantida até o sacrifício (48h pós-cirurgia). Os seguintes parâmetros foram avaliados: creatinina, ureia e fósforo plasmáticos; proteinúria, volume urinário e depuração de creatinina; TBARS e TEAC (capacidade antioxidante) plasmáticos; expressão renal de iNOS e nitrotirosina, e influxo de macrófagos. Resultados: O pré-tratamento com 75 mg de BN atenuou os parâmetros de função renal alterados pela IR, com elevação da depuração de creatinina e o volume urinário, redução da proteinúria, ureia e fósforo plasmáticos, e diminuição da expressão de iNOS, nitrotirosina e da infiltração de macrófagos. Conclusão: A ingestão de baixa quantidade de BN, previamente ao processo de IR, melhora a função renal pela inibição da infiltração de macrófagos e do estresse oxidativo.

Validation of an Experimental Model to Study Less Severe Chronic Renal Failure.

PURPOSE: The 5/6 nephrectomy, mimics the stages of human chronic renal failure (CRF), but the procedure causes severe renal functional and morphological damage that could interfere with the evaluation of therapies for slowing the progression of the disease. This study summarizes the results of renal function, histology, and immunohistochemical findings in rats undergoing a 2/3 nephrectomy. METHODS: The rats were distributed in groups according to the type of nephrectomy: CRF5/6: induced by a 5/6 renal mass reduction and CRF2/3: less severe CRF. The body weight and blood pressure were monitored, and the serum creatinine (SCr), creatinine clearance (CCr), urine osmolality, and 24-h proteinuria (PT24h) were measured. CRF progression was evaluated by the rate of decline of CCr (RCCr). Histology and immunohistochemistry were performed in the remnant kidneys. Statistical analysis was done by unpaired t-test, and a P-value < 0.05 was taken as a statistical significance. RESULTS: Compared to the CRF5/6 group, the CRF2/3 model had a lower SCr, PT24h, CCr, and variations of the SCr from baseline. The disease progression was also significantly slower. The renal histopathological findings revealed fewer chronic lesions in rats with CRF2/3. Similarly, we observed less macrophage accumulation as well as lower proliferative activity and expression of fibronectin and a-smooth muscle-actin in the CRF2/3 model. CONCLUSIONS: The CRF2/3 model presented with a pattern of less severe CRF, functionally and morphologically, compared to the classical CRF5/6 model, and the CRF2/3 model may be useful for evaluating therapeutic interventions that target the early stages of CRF.

Annexin A1 protein attenuates cyclosporine-induced renal hemodynamics changes and macrophage infiltration in rats.

BACKGROUND: Cyclosporine (CsA) remains an important immunosuppressant for transplantation and for treatment of autoimmune diseases. The most troublesome side effect of CsA is renal injury. Acute CsA-induced nephrotoxicity is characterized by reduced renal blood flow (RBF) and glomerular filtration rate (GFR) due to afferent arteriole vasoconstriction. Annexin A1 (ANXA1) is a potent anti-inflammatory protein with protective effect in renal ischemia/reperfusion injury. Here we study the effects of ANXA1 treatment in an experimental model of acute CsA nephrotoxicity. METHODS: Salt-depleted rats were randomized to treatment with VH (vehicles 1 mL/kg body weight/day), ANXA1 (Ac2-26 peptide 1 mg/kg body weight/day intraperitoneally), CsA (20 mg/kg body weight/day subcutaneously) and CsA + ANXA1 (combination) for seven days. We compared renal function and hemodynamics, renal histopathology, renal tissue macrophage infiltration and renal ANXA1 expression between the four groups. RESULTS: CsA significantly impaired GFR and RBF, caused tubular dilation and macrophage infiltration and increased ANXA1 renal tissue expression. Treatment with ANXA1 attenuated CSA-induced hemodynamic changes, tubular injury and macrophage infiltration. CONCLUSION: ANXA1 treatment attenuated renal hemodynamic injury and inflammation in an acute CsA nephrotoxicity model.

Effect of cyclosporine a on glucose interstitial concentration in renal cortex and medulla from rats.

AIM: To standardize microdialysis in rat kidneys and address cyclosporine A (CsA) effects on renal cortex and medulla interstitial glucose. METHODS: Munich-Wistar rats were treated with vehicle or CsA (15 mg/kg/day) for 3 weeks. Glucose was assessed by spectrophotometry in dialysate samples from cortex, medulla and arterial plasma. Plasma insulin was measured by radioimmunoassay. Renal blood flow (RBF) was measured by Doppler ultrasound. Creatinine and urea were measured by spectrophotometry. RESULTS: CsA significantly increased the plasma levels of urea and creatinine (1.5 +/- 0.20 vs. 0.73 +/- 0.03 mg/dl in controls, p < 0.05). Medullary glucose in control was 44% lower than arterial glucose (56 +/- 6 vs. 101 +/- 8 mg/dl, p < 0.05). At the same time, CsA increased arterial (163 +/- 35 vs. 101 +/- 8 mg/dl in controls, p < 0.05) and medullary interstitial glucose (100 +/- 18 vs. 56 +/- 6 mg/dl in controls, p < 0.05), but did not affect cortical glucose (114 +/- 21 vs. 90 +/- 11 mg/dl in controls). These changes occurred in the presence of a decreased plasma insulin level (2.7 +/- 0.2 vs. 9.3 +/- 0.4 microU/ml in controls, p < 0.05). The increment in medullary glucose in CsA group occurred despite a reduction in RBF (4.6 +/- 0.8 vs. 6.5 +/- 1.0 ml/min/kidney in controls, p < 0.05). CONCLUSIONS: Microdialysis was an adequate tool to investigate in vivo regulation of renal glucose metabolism. Renal glucose uptake was dependent on medullary cells and CsA treatment induced diabetogenic effects on renal medulla in situ.

Aspectos toxocinéticos dos inseticidas piretróides / Toxokinetic aspectos an toxicity of pyrethroid insecticides

Os piretróides são inseticidas com ampla utilização na eliminação de insetos na agricultura, campanhas de saúde pública, medicina humana, medicina veterinária e ambiente doméstico. Eles são frequentemente associados a substâncias sinergistas como o butóxido de piperonila que é responsável por um aumento da potência desses venenos. Esses inseticidas são considerados pouco tóxicos aos mamíferos em função da sua rápida biotransformação e da ausência de acúmulo destas substâncias nos tecidos. A intoxicação aguda está mais relacionada com os efeitos alérgicos do que com as manifestações neurotóxicas. A toxicidade em humanos é, portanto, caracterizado por renite, asma, cefaléia, dermatite de contato, pneumonite e menos frequentemente esta associada com um prejuízo das funções do sistema nervoso

Acidente escorpiônico de evoluçäo fatal / Scorpion accident of fatal evolution

Relatamos o caso de uma criança de cinco anos de idade, vítima de acidente escorpiônico pelo "Tityus serrulatus"(escorpiao amarelo), com evoluçao fatal mesmo após soroterapia específica. Sao analisados o quadro clínico e a evoluçao do caso com o resultado da necropsia. Mostra-se, pois, a importância desse problema sanitário haja vista a freqüente possibilidade de complicaçao dos casos, principalmente em crianças.