Navegando por Palavras-chave "Ácidos graxos de cadeia curta"

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    Butirato, produto da microbiota intestinal, previne dano aos podócitos via mecanismos epigenéticos e dependentes de receptores acoplados a proteína G
    (Universidade Federal de São Paulo (UNIFESP), 2017-07-31) Felizardo, Raphael Jose Ferreira [UNIFESP]; Camara, Niels Olsen Saraiva [UNIFESP]; http://lattes.cnpq.br/8098379714093877; http://lattes.cnpq.br/9834749309169873; Universidade Federal de São Paulo (UNIFESP)
    Introduction: Chronic Kidney Disease (CKD) is characterized by structural abnormalities and progressive decrease of kidney function until complete loss of filtration capacity. Damages to podocytes, specialized cells involved on filtration process, are one of the major causes that lead to a CKD. The literature comprises a large number of experimental attempts that focus on mitigating the damage to the podocytes. In recent years, many studies point to the gut microbiota as a modulator of intestinal and extraintestinal diseases through the generation of short chain fatty acids (SCFA). It is already known that chronic kidney patients have an imbalanced gut microbiota and lower production of SCFA. Thus, we have explored the role of butyrate, an AGCC able to regulate epigenetic processes and activate G protein coupled receptors (GPR), during the progression of experimental nephropathy induced by adriamycin, focusing mainly on the protection of podocytes. Methods: Wild type mice in a Balb/c background, Gpr109a-/- mice and Gpr109a-/-.Gpr43-/- mice were induced to develop glomerulopathy by a single dose of adriamycin and treated with butyrate. Results: Wild type mice treated with butyrate showed improvement of renal function, associated to a preserved podocyte layer in the glomerular basement membrane and reduction of pro-inflammatory and pro-fibrotic markers in the kidneys. Particularly, butyrate modulated the activity of enzymes involved on epigenetic modifications in the kidneys and changed the frequency of histone markers (H3K9Ac, H3K4me3 and H3K9me3) in the promoter region of the genes encoding synaptopodin, podocin and NEPH-1 in the podocytes. Concomitantly, treatment with butyrate was not sufficient to improve the renal function of Gpr109a -/- mice and Gpr109a-/-.Gpr43-/-mice. Activation of the receptors was associated with the regulations of small GTPases activity Rac1 and Cdc42 and maintenance of the organization of actin filaments in the podocytes grown in vitro. Conclusion: Our results demonstrate that butyrate exerts important effects on podocyte homeostasis during experimental nephropathy through epigenetic and GPR109a receptors-mediated mechanisms.
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    O papel do acetato como modulador da lesão renal aguda induzida por cisplatina
    (Universidade Federal de São Paulo (UNIFESP), 2017-12-20) Cruz, Mário Costa [UNIFESP]; Câmara, Niels Olsen Saraiva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Bacterial fermentation metabolites have increasingly been associated with systemic immune-inflammatory responses, besides their involvement in diseases such as cancer, obesity, diabetes and kidney damage. Recent evidence of a relationship between short chain fatty acids (SCFAs) and renal lesions suggests different roles of SCFAs as a therapeutic strategy for renal injury; however, their role in cisplatin-induced acute kidney injury (AKI) has not been determined. Cisplatin (CDDP) is an antineoplastic drug used in more than 500 treatment protocols for different types of cancer and its most common side effect is nephrotoxicity. Despite many efforts, no definitive treatment protocol can prevent cisplatin-induced AKI without affecting its antitumor properties. In this study, we evaluated the effect of acetate, a SCFA, as a possible protector of cisplatin-induced nephrotoxicity. We observed that acetate treatment reverses cisplatin-induced effects by preventing renal damage and decrease the level of urea, creatinine and Kim-1 in the serum. Transmission electron microscopy and Seahorse Analyzer showed that acetate prevents cisplatin-induced mitochondrial damage of renal tubule cells, restores the mitochondrial function by increasing the oxygen consumption rate (OCR), decreasing the extracellular acidification rate (ECAR) and the induction of reactive oxygen species (ROS) which results in the inhibition of cisplatin-induced cell death and AKI. The immune system plays a key role in the outcome and progression of cisplatin-induced AKI, we showed that acetate treatment prevents cisplatin-induced AKI infiltration of neutrophils and macrophages Ly6C+Ly6G- in the kidney. The macrophages CCR2 and CX3CR1 participate in the cisplatin-induced AKI while acetate treatment modulated these populations to a less inflammatory profile during renal injury. Our findings indicate that acetate ameliorates cisplatin-induced AKI both in vitro and in vivo, by a combinatory effect of preventing tubular cell death, and polarizing the macrophage-mediated inflammatory response.