@article{BenKraiemSauerNorwigetal.2021,
  author    = {Ben-Kraiem, Adel and Sauer, Reine-Solange and Norwig, Carla and Popp, Maria and Bettenhausen, Anna-Lena and Atalla, Mariam Sobhy and Brack, Alexander and Blum, Robert and Doppler, Kathrin and Rittner, Heike Lydia},
  title     = {Selective blood-nerve barrier leakiness with claudin-1 and vessel-associated macrophage loss in diabetic polyneuropathy},
  series = {Journal of Molecular Medicine},
  volume    = {99},
  journal   = {Journal of Molecular Medicine},
  number    = {9},
  doi       = {10.1007/s00109-021-02091-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265237},
  pages     = {1237-1250},
  year      = {2021},
  abstract  = {Diabetic polyneuropathy (DPN) is the most common complication in diabetes and can be painful in up to 26\% of all diabetic patients. Peripheral nerves are shielded by the blood-nerve barrier (BNB) consisting of the perineurium and endoneurial vessels. So far, there are conflicting results regarding the role and function of the BNB in the pathophysiology of DPN. In this study, we analyzed the spatiotemporal tight junction protein profile, barrier permeability, and vessel-associated macrophages in Wistar rats with streptozotocin-induced DPN. In these rats, mechanical hypersensitivity developed after 2 weeks and loss of motor function after 8 weeks, while the BNB and the blood-DRG barrier were leakier for small, but not for large molecules after 8 weeks only. The blood-spinal cord barrier remained sealed throughout the observation period. No gross changes in tight junction protein or cytokine expression were observed in all barriers to blood. However, expression of Cldn1 mRNA in perineurium was specifically downregulated in conjunction with weaker vessel-associated macrophage shielding of the BNB. Our results underline the role of specific tight junction proteins and BNB breakdown in DPN maintenance and differentiate DPN from traumatic nerve injury. Targeting claudins and sealing the BNB could stabilize pain and prevent further nerve damage.},
  language  = {en}
}
@article{BrumbergKuzkinaLapaetal.2021,
  author    = {Brumberg, Joachim and Kuzkina, Anastasia and Lapa, Constantin and Mammadova, Sona and Buck, Andreas and Volkmann, Jens and Sommer, Claudia and Isaias, Ioannis U. and Doppler, Kathrin},
  title     = {Dermal and cardiac autonomic fiber involvement in Parkinson's disease and multiple system atrophy},
  series = {Neurobiology of Disease},
  volume    = {153},
  journal   = {Neurobiology of Disease},
  doi       = {10.1016/j.nbd.2021.105332},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260061},
  pages     = {105332},
  year      = {2021},
  abstract  = {Pathological aggregates of alpha-synuclein in peripheral dermal nerve fibers can be detected in patients with idiopathic Parkinson's disease and multiple system atrophy. This study combines skin biopsy staining for p-alpha-synuclein depositions and radionuclide imaging of the heart with [\(^{123}\)I]-metaiodobenzylguanidine to explore peripheral denervation in both diseases. To this purpose, 42 patients with a clinical diagnosis of Parkinson's disease or multiple system atrophy were enrolled. All patients underwent a standardized clinical workup including neurological evaluation, neurography, and blood samples. Skin biopsies were obtained from the distal and proximal leg, back, and neck for immunofluorescence double labeling with anti-p-alpha-synuclein and anti-PGP9.5. All patients underwent myocardial [\(^{123}\)I]-metaiodobenzylguanidine scintigraphy. Dermal p-alpha-synuclein was observed in 47.6\% of Parkinson's disease patients and was mainly found in autonomic structures. 81.0\% of multiple system atrophy patients had deposits with most of cases in somatosensory fibers. The [\(^{123}\)I]-metaiodobenzylguanidine heart-to-mediastinum ratio was lower in Parkinson's disease than in multiple system atrophy patients (1.94 +/- 0.63 vs. 2.91 +/- 0.96; p < 0.0001). Irrespective of the diagnosis, uptake was lower in patients with than without p-alpha-synuclein in autonomic structures (1.42 +/- 0.51 vs. 2.74 +/- 0.83; p < 0.0001). Rare cases of Parkinson's disease with p-alpha-synuclein in somatosensory fibers and multiple system atrophy patients with deposits in autonomic structures or both fiber types presented with clinically overlapping features. In conclusion, this study suggests that alpha-synuclein contributes to peripheral neurodegeneration and mediates the impairment of cardiac sympathetic neurons in patients with synucleinopathies. Furthermore, it indicates that Parkinson's disease and multiple system atrophy share pathophysiologic mechanisms of peripheral nervous system dysfunction with a clinical overlap.},
  language  = {en}
}
@article{KuzkinaBargarSchmittetal.2021,
  author    = {Kuzkina, Anastasia and Bargar, Connor and Schmitt, Daniela and R{\"o}ßle, Jonas and Wang, Wen and Schubert, Anna-Lena and Tatsuoka, Curtis and Gunzler, Steven A. and Zou, Wen-Quan and Volkmann, Jens and Sommer, Claudia and Doppler, Kathrin and Chen, Shu G.},
  title     = {Diagnostic value of skin RT-QuIC in Parkinson's disease: a two-laboratory study},
  series = {NPJ Parkinson's Disease},
  volume    = {7},
  journal   = {NPJ Parkinson's Disease},
  number    = {1},
  doi       = {10.1038/s41531-021-00242-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260451},
  year      = {2021},
  abstract  = {Skin alpha-synuclein deposition is considered a potential biomarker for Parkinson's disease (PD). Real-time quaking-induced conversion (RT-QuIC) is a novel, ultrasensitive, and efficient seeding assay that enables the detection of minute amounts of alpha-synuclein aggregates. We aimed to determine the diagnostic accuracy, reliability, and reproducibility of alpha-synuclein RT-QuIC assay of skin biopsy for diagnosing PD and to explore its correlation with clinical markers of PD in a two-center inter-laboratory comparison study. Patients with clinically diagnosed PD (n = 34), as well as control subjects (n = 30), underwent skin punch biopsy at multiple sites (neck, lower back, thigh, and lower leg). The skin biopsy samples (198 in total) were divided in half to be analyzed by RT-QuIC assay in two independent laboratories. The a-synuclein RT-QuIC assay of multiple skin biopsies supported the clinical diagnosis of PD with a diagnostic accuracy of 88.9\% and showed a high degree of inter-rater agreement between the two laboratories (92.2\%). Higher alpha-synuclein seeding activity in RT-QuIC was shown in patients with longer disease duration and more advanced disease stage and correlated with the presence of REM sleep behavior disorder, cognitive impairment, and constipation. The alpha-synuclein RT-QuIC assay of minimally invasive skin punch biopsy is a reliable and reproducible biomarker for Parkinson's disease. Moreover, alpha-synuclein RT-QuIC seeding activity in the skin may serve as a potential indicator of progression as it correlates with the disease stage and certain non-motor symptoms.},
  language  = {en}
}
@article{SommerCarrollKoikeetal.2021,
  author    = {Sommer, Claudia and Carroll, Antonia S. and Koike, Haruki and Katsuno, Masahisa and Ort, Nora and Sobue, Gen and Vucic, Steve and Spies, Judith M. and Doppler, Kathrin and Kiernan, Matthew C.},
  title     = {Nerve biopsy in acquired neuropathies},
  series = {Journal of the Peripheral Nervous System},
  volume    = {26},
  journal   = {Journal of the Peripheral Nervous System},
  number    = {S2},
  doi       = {10.1111/jns.12464},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259555},
  pages     = {S21-S41},
  year      = {2021},
  abstract  = {A diagnosis of neuropathy can typically be determined through clinical assessment and focused investigation. With technological advances, including significant progress in genomics, the role of nerve biopsy has receded over recent years. However, making a specific and, in some cases, tissue-based diagnosis is essential across a wide array of potentially treatable acquired peripheral neuropathies. When laboratory investigations do not suggest a definitive diagnosis, nerve biopsy remains the final step to ascertain the etiology of the disease. The present review highlights the utility of nerve biopsy in confirming a diagnosis, while further illustrating the importance of a tissue-based diagnosis in relation to treatment strategies, particularly when linked to long-term immunosuppressive therapies,},
  language  = {en}
}