TY  - JOUR
A1  - Wiessler, Anna-Lena
A1  - Talucci, Ivan
A1  - Piro, Inken
A1  - Seefried, Sabine
A1  - Hörlin, Verena
A1  - Baykan, Betül B.
A1  - Tüzün, Erdem
A1  - Schaefer, Natascha
A1  - Maric, Hans M.
A1  - Sommer, Claudia
A1  - Villmann, Carmen
T1  - Glycine receptor β–targeting autoantibodies contribute to the pathology of autoimmune diseases
JF  - Neurology: Neuroimmunology & Neuroinflammation
N2  - Background and Objectives
Stiff-person syndrome (SPS) and progressive encephalomyelitis with rigidity and myoclonus (PERM) are rare neurologic disorders of the CNS. Until now, exclusive GlyRα subunit–binding autoantibodies with subsequent changes in function and surface numbers were reported. GlyR autoantibodies have also been described in patients with focal epilepsy. Autoimmune reactivity against the GlyRβ subunits has not yet been shown. Autoantibodies against GlyRα1 target the large extracellular N-terminal domain. This domain shares a high degree of sequence homology with GlyRβ making it not unlikely that GlyRβ-specific autoantibody (aAb) exist and contribute to the disease pathology.

Methods
In this study, we investigated serum samples from 58 patients for aAb specifically detecting GlyRβ. Studies in microarray format, cell-based assays, and primary spinal cord neurons and spinal cord tissue immunohistochemistry were performed to determine specific GlyRβ binding and define aAb binding to distinct protein regions. Preadsorption approaches of aAbs using living cells and the purified extracellular receptor domain were further used. Finally, functional consequences for inhibitory neurotransmission upon GlyRβ aAb binding were resolved by whole-cell patch-clamp recordings.

Results
Among 58 samples investigated, cell-based assays, tissue analysis, and preadsorption approaches revealed 2 patients with high specificity for GlyRβ aAb. Quantitative protein cluster analysis demonstrated aAb binding to synaptic GlyRβ colocalized with the scaffold protein gephyrin independent of the presence of GlyRα1. At the functional level, binding of GlyRβ aAb from both patients to its target impair glycine efficacy.

Discussion
Our study establishes GlyRβ as novel target of aAb in patients with SPS/PERM. In contrast to exclusively GlyRα1-positive sera, which alter glycine potency, aAbs against GlyRβ impair receptor efficacy for the neurotransmitter glycine. Imaging and functional analyses showed that GlyRβ aAbs antagonize inhibitory neurotransmission by affecting receptor function rather than localization.
KW  - autoantibody (aAb)
KW  - glycine receptor (GlyR)
KW  - stiff-person syndrome (SPS)
KW  - clinical neurology
KW  - movement disorders
KW  - progressive encephalitis with rigidity and myoclonus (PERM)
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-349958
VL  - 11
IS  - 2
ER  - 
TY  - JOUR
A1  - Prieto‐Garcia, Cristian
A1  - Hartmann, Oliver
A1  - Reissland, Michaela
A1  - Braun, Fabian
A1  - Fischer, Thomas
A1  - Walz, Susanne
A1  - Schülein‐Völk, Christina
A1  - Eilers, Ursula
A1  - Ade, Carsten P.
A1  - Calzado, Marco A.
A1  - Orian, Amir
A1  - Maric, Hans M.
A1  - Münch, Christian
A1  - Rosenfeldt, Mathias
A1  - Eilers, Martin
A1  - Diefenbacher, Markus E.
T1  - Maintaining protein stability of ∆Np63 via USP28 is required by squamous cancer cells
JF  - EMBO Molecular Medicine
N2  - The transcription factor ∆Np63 is a master regulator of epithelial cell identity and essential for the survival of squamous cell carcinoma (SCC) of lung, head and neck, oesophagus, cervix and skin. Here, we report that the deubiquitylase USP28 stabilizes ∆Np63 and maintains elevated ∆NP63 levels in SCC by counteracting its proteasome‐mediated degradation. Impaired USP28 activity, either genetically or pharmacologically, abrogates the transcriptional identity and suppresses growth and survival of human SCC cells. CRISPR/Cas9‐engineered in vivo mouse models establish that endogenous USP28 is strictly required for both induction and maintenance of lung SCC. Our data strongly suggest that targeting ∆Np63 abundance via inhibition of USP28 is a promising strategy for the treatment of SCC tumours.
KW  - ∆Np63
KW  - NOTCH
KW  - squamous cell carcinoma
KW  - 28
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218303
VL  - 12
IS  - 4
ER  -