Functional metabotropic glutamate receptor 1 and 5 expression in podocytes / 中华肾脏病杂志

ABSTRACT

Objective To investigate the expression of metabotropic glutamate receptor (mGluR) in murine podocytes.Methods Conditional immortalized podocytes were used in the research.RT-PCR was used to estimate the mRNA expression.Western blotting,immunofluorescence staining and immunoelectron microscopy were employed to determine the protein production.EIA,EMSA and Western blotting were used to examine the cAMP generation and cAMP response element-binding protein (CREB) activation.Intracellular calcium was investigated using confocal microscopy.Results mGluR1 and 5 mRNA and protein were expressed in murine brain and podocytes.In glomeruli,most of mGluR1 expression located in podocytes and was expressed in the submembrane space of the podocytes.Podocytes treated with (S)-3,5-dihydroxyphenylglycine (DHPG,an agonist for mGluR1/5) rapidly generated cAMP and activated CREB.(RS)-1-Aminoindan-1,5-dicarboxylic acid (AIDA,a selective antagonist of mGluR1/5) and SQ22536 (an adenylate cyclase inhibitor),but not 2-aminoethoxydiphenyl borate (2-APB an antagonist of canonical transient receptor potential) blocked DHPG-induced cAMP generation and CREB activation.Following DHPG treatment,intracellular calcium level rose and was prevented by pre-treatment with AIDA and 2-APB.DHPG-induced calcium influx was also prevented by incubation with calcium-free medium.Conclusion Podocytes express functional mGluR1 and mGluR5.