Showing papers by "Gdańsk Medical University published in 1970"
TL;DR: A novel mechanism of metformin action, which increases extracellular ATP concentration leads to activation of P2 receptors and consequent modulation of the podocytes' metabolism through AMPK and NAD(P)H oxidase which, in turn, may affect podocyte functioning.
Abstract: Hyperglycemia affects the functioning numbers of podocytes and leads to a gradual decline of renal function. The normalization of glucose level is a principle therapeutic goal in diabetic patients and metformin is a popular hypoglycemic drug used in type 2 diabetes mellitus. Metformin activates AMP-activated kinase (AMPK) and decreases NAD(P)H oxidase activity in podocytes leading to reduction of free radical generation. Similar effects are observed after activation of P2 receptors. Therefore, we investigated whether metformin increases extracellular ATP concentration and affects the activities of NAD(P)H oxidase and AMPK through P2 receptors. Experiments were performed on cultured mouse podocytes. NAD(P)H oxidase activity was measured by chemiluminescence and changes in AMPK activity were estimated by immunoblotting against AMPKα-Thr(172)-P. Metformin increased extracellular ATP concentration by reduction of ecto-ATPase activity, decreased NAD(P)H oxidase activity and increased AMPK phosphorylation. A P2 receptor antagonist, suramin (300 µM), prevented metformin action on NAD(P)H oxidase and AMPK phosphorylation. The data suggests a novel mechanism of metformin action, at least in podocytes. Metformin, which increases extracellular ATP concentration leads to activation of P2 receptors and consequent modulation of the podocytes' metabolism through AMPK and NAD(P)H oxidase which, in turn, may affect podocyte functioning.
23 citations
TL;DR: Levels of TGF-β1 protein in plasma and corresponding mRNA in intestinal tissue were significantly higher in IBD patients than in controls, and longitudinal assessment of this cytokine in a single patient may help to monitor the clinical course of IBD.
Abstract: Previously published studies on levels of the transforming growth factor-β1 (TGF-β1) protein and mRNA of the corresponding gene in patients suffering from inflammatory bowel diseases (IBD) gave varying results, leading to contradictory conclusions. To solve the contradictions, we aimed to assess longitudinally TGF-β1 protein and mRNA levels at different stages of the disease in children suffering from IBD. The study group consisted of 19 pediatric patients with IBD at the age between 3.5 and 18.4 years. The control group consisted of 42 children aged between 2.0 and 18.0 years. The plasma TGF-β1 concentration was measured with ELISA. mRNA levels of the TGF-β1 gene isolated from samples of the intestinal tissue were assessed by reverse transcription and real-time PCR. Levels of TGF-β1 protein in plasma and corresponding mRNA in intestinal tissue were significantly higher in IBD patients than in controls. TGF-β1 and corresponding transcripts were also more abundant in plasma and intestinal tissue, respectively, in patients at the active stage of the disease than during remission. In every single IBD patient, plasma TGF-β1 level and mRNA level in intestinal tissue was higher at the active stage of the disease than during remission. Levels of TGF-β1 and corresponding mRNA are elevated during the active stage of IBD but not during the remission. Longitudinal assessment of this cytokine in a single patient may help to monitor the clinical course of IBD.
2 citations