@article{NairHocherVerkaartetal.2012, author = {Nair, Anil V. and Hocher, Berthold and Verkaart, Sjoerd and van Zeeland, Femke and Pfab, Thiemo and Slowinski, Torsten and Chen, You-Peng and Schlingmann, Karl Peter and Schaller, Andre and Gallati, Sabina and Bindels, Rene J. and Konrad, Martin and H{\"o}nderop, Joost G.}, title = {Loss of insulin-induced activation of TRPM6 magnesium channels results in impaired glucose tolerance during pregnancy}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {28}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1113811109}, pages = {11324 -- 11329}, year = {2012}, abstract = {Hypomagnesemia affects insulin resistance and is a risk factor for diabetes mellitus type 2 (DM2) and gestational diabetes mellitus (GDM). Two single nucleotide polymorphisms (SNPs) in the epithelial magnesium channel TRPM6 ((VI)-I-1393, (KE)-E-1584) were predicted to confer susceptibility for DM2. Here, we show using patch clamp analysis and total internal reflection fluorescence microscopy, that insulin stimulates TRPM6 activity via a phosphoinositide 3-kinase and Rac1-mediated elevation of cell surface expression of TRPM6. Interestingly, insulin failed to activate the genetic variants TRPM6 ((VI)-I-1393) and TRPM6((KE)-E-1584), which is likely due to the inability of the insulin signaling pathway to phosphorylate TRPM6(T-1391) and TRPM6(S-1583). Moreover, by measuring total glycosylated hemoglobin (TGH) in 997 pregnant women as a measure of glucose control, we demonstrate that TRPM6((VI)-I-1393) and TRPM6((KE)-E-1584) are associated with higher TGH and confer a higher likelihood of developing GDM. The impaired response of TRPM6((VI)-I-1393) and TRPM6((KE)-E-1584) to insulin represents a unique molecular pathway leading to GDM where the defect is located in TRPM6.}, language = {en} }