کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1929992 | 1536784 | 2011 | 6 صفحه PDF | دانلود رایگان |
The ecto-nucleotide pyrophosphatase/phosphodiesterase family (E-NPPs) contains two membrane-bound members: E-NPP1 and E-NPP3. These enzymes mediate hydrolysis of extracellular nucleotides and their abnormal expression may affect intracellular signal transduction pathways, leading to cellular dysfunction, e.g., insulin resistance. Podocytes are insulin-dependent glomerular epithelial cells that regulate the glomerular filtration rate. Pathology of podocytes is a hallmark of diabetic nephropathy. Here, we investigated the expressions of E-NPP1 and E-NPP3 and activity of E-NPP enzymes in rat podocytes cultured with 5 mM (NG) or 30 mM glucose (HG). Insulin resistance was determined by measuring changes in [1,2-3H]-deoxy-d-glucose uptake in response to insulin. mRNAs of E-NPP1 and E-NPP3 were detected within podocytes. The E-NPP expressions were confirmed at the protein level using western blot and immunofluorescence techniques. At NG, insulin (300 nM, 3 min) increased glucose uptake 1.5-fold; however, this effect was abolished at HG. The protein expressions of E-NPP1 and E-NPP3 were not affected at HG. The E-NPP activities were 24.68 ± 0.72 and 26.51 ± 1.55 nmol/min/mg protein at NG and HG, respectively. In conclusion, ecto-nucleotide pyrophosphatase/phosphodiesterase 1 and 3 are expressed on podocytes, but changes in expression of these enzymes are most likely not involved in etiology of insulin resistance in podocytes.
► Ecto-nucleotide pyrophosphatase/phosphodiesterase (E-NPP) may affect cell function.
► E-NPP1 and 3 are expressed on podocytes.
► E-NPP expression is not accompanied with insulin resistance in podocytes.
Journal: Biochemical and Biophysical Research Communications - Volume 416, Issues 1–2, 9 December 2011, Pages 64–69