@article{SchaeferFriedrichJorgensenetal.2018, author = {Sch{\"a}fer, Nadine and Friedrich, Maximilian and J{\o}rgensen, Morten Egevang and Kollert, Sina and Koepsell, Hermann and Wischmeyer, Erhard and Lesch, Klaus-Peter and Geiger, Dietmar and D{\"o}ring, Frank}, title = {Functional analysis of a triplet deletion in the gene encoding the sodium glucose transporter 3, a potential risk factor for ADHD}, series = {PLoS ONE}, volume = {13}, journal = {PLoS ONE}, number = {10}, doi = {10.1371/journal.pone.0205109}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176495}, pages = {e0205109}, year = {2018}, abstract = {Sodium-glucose transporters (SGLT) belong to the solute carrier 5 family, which is characterized by sodium dependent transport of sugars and other solutes. In contrast, the human SGLT3 (hSGLT3) isoform, encoded by SLC5A4, acts as a glucose sensor that does not transport sugar but induces membrane depolarization by Na\(^{+}\) currents upon ligand binding. Whole-exome sequencing (WES) of several extended pedigrees with high density of attention-deficit/hyperactivity disorder (ADHD) identified a triplet ATG deletion in SLC5A4 leading to a single amino acid loss (ΔM500) in the hSGLT3 protein imperfectly co-segregating with the clinical phenotype of ADHD. Since mutations in homologous domains of hSGLT1 and hSGLT2 were found to affect intestinal and renal function, respectively, we analyzed the functional properties of hSGLT3[wt] and [ΔM500] by voltage clamp and current clamp recordings from cRNA-injected Xenopus laevis oocytes. The cation conductance of hSGLT3[wt] was activated by application of glucose or the specific agonist 1-desoxynojirimycin (DNJ) as revealed by inward currents in the voltage clamp configuration and cell depolarization in the current clamp mode. Almost no currents and changes in membrane potential were observed when glucose or DNJ were applied to hSGLT3[ΔM500]-injected oocytes, demonstrating a loss of function by this amino acid deletion in hSGLT3. To monitor membrane targeting of wt and mutant hSGLT3, fusion constructs with YFP were generated, heterologously expressed in Xenopus laevis oocytes and analyzed for membrane fluorescence by confocal microscopy. In comparison to hSGLT3[wt] the fluorescent signal of mutant [ΔM500] was reduced by 43\% indicating that the mutant phenotype might mainly result from inaccurate membrane targeting. As revealed by homology modeling, residue M500 is located in TM11 suggesting that in addition to the core structure (TM1-TM10) of the transporter, the surrounding TMs are equally crucial for transport/sensor function. In conclusion, our findings indicate that the deletion [ΔM500] in hSGLT3 inhibits membrane targeting and thus largely disrupts glucose-induced sodium conductance, which may, in interaction with other ADHD risk-related gene variants, influence the risk for ADHD in deletion carriers.}, language = {en} } @article{JanschGuentherWaideretal.2018, author = {Jansch, Charline and G{\"u}nther, Katharina and Waider, Jonas and Ziegler, Georg C. and Forero, Andrea and Kollert, Sina and Svirin, Evgeniy and P{\"u}hringer, Dirk and Kwok, Chee Keong and Ullmann, Reinhard and Maierhofer, Anna and Flunkert, Julia and Haaf, Thomas and Edenhofer, Frank and Lesch, Klaus-Peter}, title = {Generation of a human induced pluripotent stem cell (iPSC) line from a 51-year-old female with attention-deficit/hyperactivity disorder (ADHD) carrying a duplication of SLC2A3}, series = {Stem Cell Research}, volume = {28}, journal = {Stem Cell Research}, doi = {10.1016/j.scr.2018.02.005}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176654}, pages = {136-140}, year = {2018}, abstract = {Fibroblasts were isolated from a skin biopsy of a clinically diagnosed 51-year-old female attention-deficit/hyperactivity disorder (ADHD) patient carrying a duplication of SLC2A3, a gene encoding neuronal glucose transporter-3 (GLUT3). Patient fibroblasts were infected with Sendai virus, a single-stranded RNA virus, to generate transgene-free human induced pluripotent stem cells (iPSCs). SLC2A3-D2-iPSCs showed expression of pluripotency-associated markers, were able to differentiate into cells of the three germ layers in vitro and had a normal female karyotype. This in vitro cellular model can be used to study the role of risk genes in the pathogenesis of ADHD, in a patient-specific manner.}, language = {en} } @article{FrankeMicheliniAshersonetal.2018, author = {Franke, Barbara and Michelini, Giorgia and Asherson, Philip and Banaschewski, Tobias and Bilbow, Andrea and Buitelaar, Jan K. and Cormand, Bru and Faraone, Stephen V. and Ginsberg, Ylva and Haavik, Jan and Kuntsi, Jonna and Larsson, Henrik and Lesch, Klaus-Peter and Ramos-Quiroga, J. Antoni and R{\´e}thelyi, J{\´a}nos M. and Ribases, Marta and Reif, Andreas}, title = {Live fast, die young? A review on the developmental trajectories of ADHD across the lifespan}, series = {European Neuropsychopharmacology}, volume = {28}, journal = {European Neuropsychopharmacology}, doi = {10.1016/j.euroneuro.2018.08.001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228407}, pages = {1059-1088}, year = {2018}, abstract = {Attention-deficit/hyperactivity disorder (ADHD) is highly heritable and the most common neurodevelopmental disorder in childhood. In recent decades, it has been appreciated that in a substantial number of cases the disorder does not remit in puberty, but persists into adulthood. Both in childhood and adulthood, ADHD is characterised by substantial comorbidity including substance use, depression, anxiety, and accidents. However, course and symptoms of the disorder and the comorbidities may fluctuate and change over time, and even age of onset in childhood has recently been questioned. Available evidence to date is poor and largely inconsistent with regard to the predictors of persistence versus remittance. Likewise, the development of comorbid disorders cannot be foreseen early on, hampering preventive measures. These facts call for a lifespan perspective on ADHD from childhood to old age. In this selective review, we summarise current knowledge of the long-term course of ADHD, with an emphasis on clinical symptom and cognitive trajectories, treatment effects over the lifespan, and the development of comorbidities. Also, we summarise current knowledge and important unresolved issues on biological factors underlying different ADHD trajectories. We conclude that a severe lack of knowledge on lifespan aspects in ADHD still exists for nearly every aspect reviewed. We encourage large-scale research efforts to overcome those knowledge gaps through appropriately granular longitudinal studies.}, language = {en} }