Navegando por Palavras-chave "Podócitos"

Agora exibindo 1 - 6 de 6
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Detecção de podocitúria em pacientes transplantados renais por PCR em tempo real: associação com características clínicas e histopatológicas
    (Universidade Federal de São Paulo (UNIFESP), 2018-11-28) Andrade, João Marcelo Medeiros de [UNIFESP]; Casarini, Dulce Elena [UNIFESP]; Torres, Leuridan Cavalcante [UNIFESP]; http://lattes.cnpq.br/4973562538598237; http://lattes.cnpq.br/0534906942293338; http://lattes.cnpq.br/0609807795827295; Universidade Federal de São Paulo (UNIFESP)
    Podocyturia has been identified as a prognostic factor in glomerulopathies, it is associated with histological findings characterized as high probability of progression to end stage renal disease. The role of podocyturia in kidney transplantation is unknown. The aim of this study was to evaluate the association between podocyturia and clinical and histological findings of kidney transplanted patients. This is a crosssectional, exploratory and translational study developed at the Instituto de Medicina Integral Prof. Fernando Figueira (IMIP) and at the Translational Research Laboratory A. C. Hart. The following study groups were established according to inclusion and exclusion criteria: renal transplant patients (PTR, n=152), aged between 18 and 70 years, who underwent protocol biopsies at 3 months (PTR3m, n=98) and at 24 months (PTR24m, n=54); negative control volunteers (PCN, n=15) composed by healthy volunteers and a positive control group (PCP, n=15) formed by pregnant women with preeclampsia according to the criteria of the International Society for the Study of Hypertension in Pregnancy (ISSHP), used for polymerase chain reaction (qPCR) validation. Podocyturia was determined by analyzing the messenger RNA (RNAm) expression in the urinary sediment of 5 podocyte-linked genes: NPHS1 (nephrin), NPHS2 (podocin), ACTN4 (alpha-actinin 4), PODXL (podocalyxin) and SYNPO2 (synaptopodin). Our results confirm that gene amplification occurs for ACTN4, SYNPO2, PODXL, NPHS1 and NPHS2 in 151 (99,34%), 151 (99,34%), 93 (61,18%), 81 (53,2%), 76 (50,0%) patients, respectively. The 5 genes expression was increased in the PTR group, compared to the PCN group, NPHS1 8,96x (p<0.0001), NPHS2 9,36x (p<0.0001), ACTN4 8,79x (p<0.0001), PODXL 8,61x (p <0.0001) and SYNPO2 9,12x(p <0.0001). There was no association between gene expression levels and R Alb/cr levels, as well as renal function. The correlation of NPHS2 gene expression levels with R Alb/cr was significant (p=0,003; r=0.38). No significant relationship was found between protocol biopsy findings at 3 months and 24 months with urinary podocytes gene expression. This study shows that there is a higher podocyte urinary loss in kidney transplant patients and that qPCR is a good method to determine podocytes genes expression in urine. The NPHS2 gene expression levels correlate with R Alb/cr levels. However, the analyzed genes cannot be considered as predictive biomarker of active glomerular disease.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Estudo do eixo intestino-rim: as alterações na microbiota intestinal em um modelo experimental de nefropatia induzida pela adriamicina
    (Universidade Federal de São Paulo (UNIFESP), 2018-04-28) Silva, Denis Goncalves [UNIFESP]; Camara, Niels Olsen Saraiva [UNIFESP]; http://lattes.cnpq.br/8098379714093877; http://lattes.cnpq.br/1625763026411693
    Introduction: Kidney diseases are a global epidemic, with a high economic burden for global health systems. Recently, the gut-kidney axis is gaining strength as organs that influence each other, however little is known on how glomerulopathies, as Focal segmental glomerulosclerosis (FSGS), can modify and affect the composition of the gut microbiota and metabolites. The progressive loss of podocytes is a major cause of chronic kidney disease (CKD), with a high prevalence rate and limited current etiological knowledge. Objective: Explore the interrelationship between the renal injury caused by glomerular dysfunction and changes in gut microbiota. Methods: Wild type Balb/c mice were chemically-induced to develop glomerulopathy (Adriamycin, ADR) and were evaluated for 30 days. In parallel, 14 days before receiving ADR, a group of Balb/c mice underwent microbiota depletion, administering broad spectrum antibiotics (ampicillin, metronidazole, neomycin, vancomycin) in autoclaved drinking water and then they were induced the same way to develop glomerulopathy. Results: ADR caused renal histopathological lesions, such as glomerular collapse, decreased number of podocytes per glomerulus, glomerular barrier dysfunction and uremia. In addition, ADR-induced animals showed histological changes in gut colon, with increased levels in amorphous cell mass and a decrease in claudin-1 expression. Structural changes in intestinal colon were also associated with gut microbiota dysbiosis, with reduced Bacteroidetes phylum and less gut mucus. Disease-induced animals that had previously depleted gut microbiota exhibited better glomerular barrier function, with lower levels of protein and albumin in the urine. Conclusion: Our results shows, for the first time in literature, that the development of ADR-induced glomerulopathy promotes changes in the structure of the colon and in the proportion of gut bacterial phyla. Interestingly, initial results showed that depletion of gut microbiota conferred protection to the loss of glomerular barrier function.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    A investigação do inflamassoma NLRP3 no desenvolvimento da glomeruloesclerose segmentar e focal experimental
    (Universidade Federal de São Paulo (UNIFESP), 2020-01-30) Santos, Amandda Rakel Peixoto Dos [UNIFESP]; Silva Filho, Alvaro Pacheco E [UNIFESP]; Universidade Federal de São Paulo
    Introduction. Chronic inflammation has been associated with several diseases including chronic kidney disease (CKD), and among those, focal segmental glomerulosclerosis (FSGS), a glomerulopathy in which inflammatory and degenerative mechanisms are implicated in podocyte damage. FSGS is a disease in which 50% of the patients are resistant to corticotherapy. In the past decades, the innate immune sensor system called NLRP3 inflammasome has been widely studied, showing its important contribution to the immune response. However, little has been investigated about FSGS and NLRP3 inflammasome. Aims. As it has been observed in other diseases, we speculated that NLRP3 inflammasome may also contribute to the development of FSGS. Therefore, we have investigated NLRP3 inflammasome components in experimental FSGS in order to unravel new mechanisms of the immune responses in renal diseases. Methods. Through Adriamycin Nephropathy (DOX) in wild type mice, C57BL/6J, mutants, such as NLRP3 KO, ASC KO, CASP-1 KO, and CRE Lox transgenic mice, we evaluated and compared NLRP3 inflammasome activation. We studied renal function, as well as gene and protein expression of molecules associated with podocytopathy, inflammation and tissue repair. Results. Our data showed that NLRP3 inflammasome activation happened early, in the second day of the nephropathy model, in C57BL/6J, with increased expression of nlrp3 (p=0,0275), casp-1 (p=0,0038), pro-il-18 (p<0,0001) and serum IL-18 (p<0,0001), associated with diminished expression of genes responsible for structural podocytes proteins and slit diaphragm proteins, actn4, synpo, nphs1 and kirrel (p<0,0001), we have also found diminished numbers of podocytes, WT1 (p=0,0009), and podocyte effacement through transmission electron microscopy (TEM). Among the knockout and CRE Lox transgenic mice, we pointed out that NLRP3 KO were protected against DOX- induced injury, podocytes mainly, not showing differences in podocytes molecules expression between the groups (p>0,05), or significant changes in podocytes structure by TEM; and, although they have presented increased expression of col4a1 (p=0,0056), fsp-1 (p=0,0217) and il-33 (p=0,0132), the mmp9/timp1 ratio was decreased (p<0,0001), indicating less extracellular matrix deposit when nlrp3 is not present. Conclusions. Our results indicated that NLRP3 inflammasome participates in experimental FSGS development, specially through IL-18 and IL-33 modulation. We believe that NLRP3 inflammasome activation promotes severe podocyte damage through IL-18, but, on the other hand, without NLRP3 inflammasome, IL-33 is not inactivated by caspase-1, and without this important limiting mechanism, IL-33 induces cellular infiltration and augmented expression of pro-fibrotic molecules. Thus, NLRP3 inflammasome and FSGS relation should be deeply investigated to guide the development of drugs that act accurately, blocking podocyte damage, without compromising the surveillance of this important innate immunity component.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    O papel dos receptores de cininas na Glomeruloesclerose segmentar e focal experimental
    (Universidade Federal de São Paulo (UNIFESP), 2012) Pereira, Rafael Luiz [UNIFESP]
    A glomeruloesclerose segmentar e focal (GESF) e uma das principais causas de insufiCiência renal cronica (IRC) no mundo. E uma doenca caracterizada por lesoes fibroticas glomerulares e tubulares associadas ao acometimento das celulas epiteliais viscerais (podocitos), o que leva a perda da permeseletividade glomerular e consequente proteinuria. Modelos experimentais de GESF sao desenvolvidos por meio da utilizacao de drogas que induzem sinais que mimetizam a GESF humana, dentre essas drogas, uma que vem sendo citada classicamente na literatura e a Adriamicina (ADM). Devido a morbidade e mortalidades elevadas das doencas renais, diversos estudos acerca de mecanismos renoprotetores em humanos e modelos experimentais vem sendo desenvolvidos. Dentre esses estudos, destacam-se aqueles acerca do papel dos sistemas das cininas. Diversos trabalhos evidenciam o importante papel desse sistema, em especial de seus receptores, o B1RBK e o B2RBK, amenizando ou exacerbando a progressao de varios modelos experimentais. Apesar de varios dados da literatura apontarem os receptores de cininas, como alvo terapeutico em doencas renais, nenhum trabalho ate o momento tinha mostrado o papel dos mesmos na progressao da GESF. Nosso trabalho visou estudar o papel dos receptores de cininas na progressao da GESF induzida por ADM. Verificamos um aumento da expressao dos receptores de cininas ao longo da progressao da GESF, em especial do B1RBK 24h e do B2RBK 7 dias apos administracao da ADM. O proximo passo foi a ativacao do receptor B1RBK, atraves da utilizacao de um agonista especifico, o DABK. Esse agonista aumentou os indices de proteinuria e albuminuria dos animais em comparacao ao grupo somente tratado com ADM, alem de contribuir para diminuicao da expressao de moleculas podocitarias como a podocina. Por outro lado, o uso do antagonista especifico de B1RBK, o DALBK, que preveniu, e o mais importante reverteu diversos sinais da GESF. O uso desse antagonista aumentou a expressao de mRNA e proteinas de moleculas podocitarias, como a nefrina, podocina e alfa-actinina-4, alem de prevenir o aumento de sinais fibroticos , pro-inflamatorios e a infiltracao de macrofagos, caracteristicos da GESF. Essa protecao foi evidenciada com a observacao da preservacao da arquitetura podocitaria no grupo de animais tratados com DALBK, associada a prevencao do desenvolvimento da esclerose segmentar. Em uma segunda parte de nosso trabalho modulamos a participacao do receptor B2RBK, com o uso de um antagonista especifico, o HOE-140. O uso de HOE-140, assim como o DALBK, preveniu e reverteu diversos sinais da GESF, como aumento de citocinas proinflamatorias, infiltracao de macrofagos associada a um aumento de moleculas quimioatratoras para os mesmos e esclerose glomerular associada a proteinuria e albuminuria. Mesmo em longo prazo, o bloqueio dos receptores de cininas, tanto o B1RBK quanto o B2RBK foram capazes de proteger os animais dos sinais da GESF. No caso a protecao via bloqueio de B2RBK, parece estar envolvida com a diminuicao da expressao de B1RBK, pois o uso do HOE-140 diminuiu a expressao desse receptor, que esta associado a producao de citocinas pro-inflamatorias como a IL-1β e TNF-α, fatores relacionados a lesao podocitaria. Esse trabalho foi o primeiro a mostrar a importancia dos receptores de cininas na GESF, mostrando que ambos os receptores B1RBK e B2RBK quando bloqueados contribuem para prevencao e reversao dos sinais dessa doenca, fazendo dos mesmos potenciais alvos terapeuticos a serem estudados
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Pesquisa De Podocitúria: Desenvolvimento E Padronização De Métodos
    (Universidade Federal de São Paulo (UNIFESP), 2018-02-22) Pereira, Amelia Rodrigues [UNIFESP]; Kirsztajn, Gianna Mastroianni [UNIFESP]
    Introduction: Podocytes Are Fundamental Cells For Maintaining The Functionality Of The Glomerular Filtration Barrier, Which Is Characterized By Selective Permeability. Podocyturia, Excretion Of Podocytes In Urine, Has Been Studied In Several Glomerulopathies As A Potential Marker Of Disease Activity. It Is A Non-Invasive Method That Can Reflect In Real Time The Podocyte Lesion, And It Can Be A More Sensitive And Earlier Marker Of This Kind Of Lesion. It Presents Potential Applicability In Assessing The Activity Of Glomerular Diseases And Understanding Their Pathogenesis, As Well As Guiding Future Therapeutic Interventions. Objectives: To Standardize And Validate The Methodology For The Investigation Of Podocyturia By Two Techniques, Indirect Immunofluorescence And Quantification By Polymerase Chain Reaction In Real Time, In Addition To Determine Which Technique Is Most Suitable For This Purpose. Material And Methods: The Study Of Podocyturia Occurred In A Group Of 71 Individuals, 21 (29,17%) Patients With Foc
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Podocituria: e indicativo de pre-eclampsia? Avaliacao de parametros renais e podocituria na pre-eclampsia
    (Universidade Federal de São Paulo (UNIFESP), 2011) Facca, Thais Alquezar [UNIFESP]
    Introdução: Pre-eclampsia (PE) e uma importante causa de glomerulopatia. Recentemente, a pesquisa de podocituria foi descrita como um marcador precoce de lesao renal na gestacao, mas ainda precisa ser testada. A determinacao urinaria da proteina transportadora de retinol (RBP) e um marcador de disfuncao tubular proximal, a albuminuria e um marcador de dano vascular e a relacao proteina total/creatinina (RPC) urinaria tem o seu papel como teste preditivo de doenca renal ao longo da vida. Objetivos: Deteminar se a podocituria esta presente na PE e na gestacao normal e correlaciona-la com outros parametros renais. Metodos: Estudo caso-controle com 39 pacientes com idade gestacional (IG) superior a 20 semanas. Grupo controle (GC), n=25; grupo PE, n=14.Foram avaliadas proteinuria isolada, albuminuria, relacao albumina/creatinina (RAC) urinaria, RPC urinaria e RBP urinaria. Resultados: As medias dos dados avaliados no GC e na PE foram respectivamente: idade de 26,9 e 26,4 anos; IG de 37,1 e 30,6 semanas; RBP urinaria de 0,4 mg/L e 2,0 mg/L; albuminuria de 7,3 mg/L e 2267,4 mg/L; RAC urinaria de 8,2 mg/g e 3778,9 mg/g. Media da RPC urinaria na PE de 6,7. Nao houve diferenca estatisticamente significante entre a podocituria na PE e no GC. Conclusao: Albuminuria, RBP, PCR e PAC urinarias estao elevadas na PE em comparacao ao GC. Podocituria nao se revelou um bom preditor de PE na populacao estudada. A avaliacao renal na gestacao pode adicionar importante informacao clinica e no que tange a deteccao e seguimento de glomerulopatias