RESUMEN
Renal fibrosis is the usual outcome of an excessive accumulation of extracellular matrix (ECM) that frequently occurs in membranous and diabetic nephropathy. The result of renal fibrosis would be end-stage renal failure, which requires costly dialysis or kidney transplantation. Renal fibrosis typically results from chronic inflammation via production of several molecules, such as growth factors, angiogenic factors, fibrogenic cytokines, and proteinase. All of these factors can stimulate excessive accumulation of ECM components through epithelial to mesenchymal transition (EMT), which results in renal fibrosis. Among these, transforming growth factor-beta (TGF-ß) is proposed to be the major regulator in inducing EMT. Besides ECM protein synthesis, TGF-ß is involved in hypertrophy, proliferation, and apoptosis in renal cells. In particular, TGF-ß is likely to be most potent and ubiquitous profibrotic factor acting through several intracellular signaling pathways including protein kinases and transcription factors. Factors that regulate TGF-ß expression in renal cell include hyperglycemia, angiotensin II, advance glycation end products, complement activation (C5b-9), and oxidative stress. Over the past several years, the common understanding of the pathogenic factors that lead to renal fibrosis in nephropathy has improved considerably. This review will discuss the recent findings on the mechanisms and role of TGF-ß in membranous and diabetic nephropathy.
Asunto(s)
Nefropatías Diabéticas , Transición Epitelial-Mesenquimal/inmunología , Matriz Extracelular , Factor de Crecimiento Transformador beta/inmunología , Animales , Nefropatías Diabéticas/inmunología , Nefropatías Diabéticas/patología , Matriz Extracelular/inmunología , Matriz Extracelular/patología , Fibrosis , HumanosRESUMEN
In recent years, oxidative stress has been implicated in the pathophysiology of a large number of diseases or disorders which are initiated and/or exacerbated by pro-oxidants such as various drugs including alcohol and food additives. The present study was carried out to evaluate the effects of oral treatment with polyherbal formulation Normeta (2 ml and 4 ml/kg) on hepatic damage induced by alcohol 10-30% (blood alcohol was maintained at levels between 150 and 350 mg/dl), thermally oxidized oil (polyunsaturated fatty acids) (15% of diet) and carbonyl iron (1.5-2% of diet) for 30 days in rats. In vitro studies with 1, 1-Diphenyl, 2-Picrylhydrazyl (DPPH), Nitric oxide and Ferric chloride (Fe(+3) ions) showed that Normeta possesses antioxidant and metal chelating activity. Alcohol, polyunsaturated fatty acids and iron feeding produced an increase in serum levels of iron, serum glutamate pyruvate transaminase and decrease in serum proteins. It was also associated with elevated lipid peroxidation (thiobarbituric acid reactive substances) and disruption of antioxidant defence mechanism in liver, decreased body weight and increased liver to body weight ratio. Oral administration of Normeta along with alcohol, polyunsaturated fatty acids and iron decreased the serum iron, serum glutamate pyruvate transaminase levels and increased serum protein levels. The levels of liver thiobarbituric acid reactive substances were decreased and the activities of antioxidant enzymes superoxide dismutase and catalase were increased. Improvement in body weight and liver to body weight ratio was also observed. The effects of Normeta on physico-metabolic parameters were comparable with silymarin. This indicates that Normeta has favourable effect in bringing down the severity of hepatotoxicity.