Effect Of The High Consistency Amino Acids On Human Renal Tubular Epithelial Cells

Objective: This experiment simulates the status of amino acid in plasma of person who have a large amount of dietary protein intake. To investigate the influence on the proliferation of renal tubular epithelial cells, the excrete of transforming growth factorβ1(TGF-β1) and express of the angiotensinⅡreceptor typeⅠ(ATR1) by high-consistency mixing amino acids, high-consistency glycine and high-consistency lysine.Methods: Human renal tubular epithelial cells (HK-2 cell) at logarithmic phase are adopted and placed in different types of amino acid to culture for 12 hours, 24 hours, 36 hours and 48 hours. There are four groups: Control group (RPMI-1640 solution, with 5% of blood serum); High-consistency mixing amino acid solution group (For each type of amino acid, the level is 1.5 to 6 times of corresponding level in 1640 solution, with 5% of blood serum); High-consistency glycine solution group (only the glycine consistency is higher than 1640 solution, with 5% of blood serum); High-consistency lysine solution group (only the lysine consistency is higher than 1640 solution, with 5% of blood serum). The proliferation ability of cells is inspected with MTT, thereby the influence on HK-2 cell proliferation by different solutions after different effecting time is observed. Select the time when the stimulation on proliferation is the most obvious and use ELISA to inspect the consistency of TGF-β1 in the supernatant, use immunocytochemical stain to inspect the status of AT1R's expression. All data are expressed with mean and standard deviation ((?)±s), use SPSS 13.00 statistic software to make statistic analysis, if double P is less than or equal to 0.05, the result has its statistical significance.Results: 1. MTT experiment shows that HK-2 proliferation is stimulated in high-consistency mixing amino acid group, single high-consistency glycine group and lysine group. Comparing with control group, the optical density of each group is added (p＜0.05). For each group, the proliferation effect starts at the 24th hour, at the 36th hour the proliferation rate is the biggest, after 48 hours the proliferation rate drops a little. Comparing with the other two experiment groups, the proliferation effect of high-consistency mixing amino acid group is more obvious and the optical density of this group is bigger (p＜0.05). After comparing respective data, the proliferation rate of glycine group and lysine group are similar (p＞0.05).2. ELISA results show the TGF-β1 consistency in the supernatant intervened by high-consistency mixing amino acid rises obviously, it has a statistical sense comparing with the control group (p＜0.05). For glycine group and lysine group, there is no TGF-β1 consistency difference comparing with control group (p＞0.05).3. Immunocytochemical stain shows the AT1R expression by HK-2 is more obvious after high-consistency mixing amino acid culture, comparing with control group the coloration is obviously deeper. For glycine group and lysine group, there is no AT1R expression difference comparing with control group (p＞0.05).Conclusion: 1. High-consistency mixing amino acid, high-consistency glycine and high-consistency lysine can promote the proliferation of renal tubular epithelial cells. The promotion effect starts at the 24th hour, reaches the summit at the 36th hour. The high-consistency mixing amino acid has an obviously better proliferation effect, while the high-consistency glycine and lysine have similar proliferation effect.2. High-consistency mixing amino acid promotes renal tubular epithelial cells to excrete more TGF-β1. High-consistency glycine and high-consistency lysine do not have such effect.3. High-consistency mixing amino acid promotes renal tubular epithelial cells express AT1R better. High-consistency glycine and high-consistency lysine do not have such effect.