@article{PoppSchmittBoehrerLangeretal.2021,
  author    = {Popp, Sandy and Schmitt-B{\"o}hrer, Angelika and Langer, Simon and Hofmann, Ulrich and Hommers, Leif and Schuh, Kai and Frantz, Stefan and Lesch, Klaus-Peter and Frey, Anna},
  title     = {5-HTT Deficiency in Male Mice Affects Healing and Behavior after Myocardial Infarction},
  series = {Journal of Clinical Medicine},
  volume    = {10},
  journal   = {Journal of Clinical Medicine},
  number    = {14},
  issn      = {2077-0383},
  doi       = {10.3390/jcm10143104},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242739},
  year      = {2021},
  abstract  = {Anxiety disorders and depression are common comorbidities in cardiac patients. Mice lacking the serotonin transporter (5-HTT) exhibit increased anxiety-like behavior. However, the role of 5-HTT deficiency on cardiac aging, and on healing and remodeling processes after myocardial infarction (MI), remains unclear. Cardiological evaluation of experimentally na{\"i}ve male mice revealed a mild cardiac dysfunction in ≥4-month-old 5-HTT knockout (-/-) animals. Following induction of chronic cardiac dysfunction (CCD) by MI vs. sham operation 5-HTT-/- mice with infarct sizes >30\% experienced 100\% mortality, while 50\% of 5-HTT+/- and 37\% of 5-HTT+/+ animals with large MI survived the 8-week observation period. Surviving (sham and MI < 30\%) 5-HTT-/- mutants displayed reduced exploratory activity and increased anxiety-like behavior in different approach-avoidance tasks. However, CCD failed to provoke a depressive-like behavioral response in either 5-Htt genotype. Mechanistic analyses were performed on mice 3 days post-MI. Electrocardiography, histology and FACS of inflammatory cells revealed no abnormalities. However, gene expression of inflammation-related cytokines (TGF-β, TNF-α, IL-6) and MMP-2, a protein involved in the breakdown of extracellular matrix, was significantly increased in 5-HTT-/- mice after MI. This study shows that 5-HTT deficiency leads to age-dependent cardiac dysfunction and disrupted early healing after MI probably due to alterations of inflammatory processes in mice.},
  language  = {en}
}
@article{KlenkHommersLohse2022,
  author    = {Klenk, Christoph and Hommers, Leif and Lohse, Martin J.},
  title     = {Proteolytic cleavage of the extracellular domain affects signaling of parathyroid hormone 1 receptor},
  series = {Frontiers in Endocrinology},
  volume    = {13},
  journal   = {Frontiers in Endocrinology},
  issn      = {1664-2392},
  doi       = {10.3389/fendo.2022.839351},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262055},
  year      = {2022},
  abstract  = {Parathyroid hormone 1 receptor (PTH1R) is a member of the class B family of G protein-coupled receptors, which are characterized by a large extracellular domain required for ligand binding. We have previously shown that the extracellular domain of PTH1R is subject to metalloproteinase cleavage in vivo that is regulated by ligand-induced receptor trafficking and leads to impaired stability of PTH1R. In this work, we localize the cleavage site in the first loop of the extracellular domain using amino-terminal protein sequencing of purified receptor and by mutagenesis studies. We further show, that a receptor mutant not susceptible to proteolytic cleavage exhibits reduced signaling to G\(_s\) and increased activation of G\(_q\) compared to wild-type PTH1R. These findings indicate that the extracellular domain modulates PTH1R signaling specificity, and that its cleavage affects receptor signaling.},
  language  = {en}
}
@article{JeanclosAlbersenRamosetal.2019,
  author    = {Jeanclos, Elisabeth and Albersen, Monique and Ramos, R{\´u}ben J. J. and Raab, Annette and Wilhelm, Christian and Hommers, Leif and Lesch, Klaus-Peter and Verhoeven-Duif, Nanda M. and Gohla, Antje},
  title     = {Improved cognition, mild anxiety-like behavior and decreased motor performance in pyridoxal phosphatase-deficient mice},
  series = {BBA - Molecular Basis of Disease},
  volume    = {1865},
  journal   = {BBA - Molecular Basis of Disease},
  doi       = {10.1016/j.bbadis.2018.08.018},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323396},
  pages     = {193-205},
  year      = {2019},
  abstract  = {Pyridoxal 5′-phosphate (PLP) is an essential cofactor in the catalysis of ~140 different enzymatic reactions. A pharmacological elevation of cellular PLP concentrations is of interest in neuropsychiatric diseases, but whole-body consequences of higher intracellular PLP levels are unknown. To address this question, we have generated mice allowing a conditional ablation of the PLP phosphatase PDXP. Ubiquitous PDXP deletion increased PLP levels in brain, skeletal muscle and red blood cells up to 3-fold compared to control mice, demonstrating that PDXP acts as a major regulator of cellular PLP concentrations in vivo. Neurotransmitter analysis revealed that the concentrations of dopamine, serotonin, epinephrine and glutamate were unchanged in the brains of PDXP knockout mice. However, the levels of γ-aminobutyric acid (GABA) increased by ~20\%, demonstrating that elevated PLP levels can drive additional GABA production. Behavioral phenotyping of PDXP knockout mice revealed improved spatial learning and memory, and a mild anxiety-like behavior. Consistent with elevated GABA levels in the brain, PDXP loss in neural cells decreased performance in motor tests, whereas PDXP-deficiency in skeletal muscle increased grip strength. Our findings suggest that PDXP is involved in the fine-tuning of GABA biosynthesis. Pharmacological inhibition of PDXP might correct the excitatory/inhibitory imbalance in some neuropsychiatric diseases.},
  language  = {en}
}