@article{OezdağAcarlıKleinEgenolfetal.2022, author = {{\"O}zdağ Acarl{\i}, Ay{\c{s}}e Nur and Klein, Thomas and Egenolf, Nadine and Sommer, Claudia and {\"U}{\c{c}}eyler, Nurcan}, title = {Subepidermal Schwann cell counts correlate with skin innervation - an exploratory study}, series = {Muscle \& Nerve}, volume = {65}, journal = {Muscle \& Nerve}, number = {4}, doi = {10.1002/mus.27496}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318726}, pages = {471 -- 479}, year = {2022}, abstract = {Introduction/Aims Schwann cell clusters have been described at the murine dermis-epidermis border. We quantified dermal Schwann cells in the skin of patients with small-fiber neuropathy (SFN) compared with healthy controls to correlate with the clinical phenotype. Methods Skin punch biopsies from the lower legs of 28 patients with SFN (11 men, 17 women; median age, 54 [range, 19-73] years) and 9 healthy controls (five men, four women, median age, 34 [range, 25-69] years) were immunoreacted for S100 calcium-binding protein B as a Schwann cell marker, protein-gene product 9.5 as a pan-neuronal marker, and CD207 as a Langerhans cell marker. Intraepidermal nerve fiber density (IENFD) and subepidermal Schwann cell counts were determined. Results Skin samples of patients with SFN showed lower IENFD (P < .05), fewer Schwann cells per millimeter (P < .01), and fewer Schwann cell clusters per millimeter (P < .05) than controls. When comparing SFN patients with reduced (n = 13; median age, 53 [range, 19-73] years) and normal distal (n = 15, median age, 54 [range, 43-68] years) IENFD, the number of solitary Schwann cells per millimeter (p < .01) and subepidermal nerve fibers associated with Schwann cell branches (P < .05) were lower in patients with reduced IENFD. All three parameters correlated positively with distal IENFD (P < .05 to P < .01), whereas no correlation was found between Schwann cell counts and clinical pain characteristics. Discussion Our data raise questions about the mechanisms underlying the interdependence of dermal Schwann cells and skin innervation in SFN. The temporal course and functional impact of Schwann cell presence and kinetics need further investigation.}, language = {en} } @phdthesis{Fischer2008, author = {Fischer, Stefan Martin}, title = {Regulation and functional consequences of MCP-1 expression in a model of Charcot-Marie-Tooth 1B disease}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-29189}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Charcot-Marie-Tooth 1B (CMT1B) is a progressive inherited demyelinating disease of human peripheral nervous system leading to sensory and/or motor function disability and is caused by mutations in the P0 gene. Mice heterozygously deficient for P0 (P0+/-) are an adequate model of this human disorder showing myelin degeneration, formation of onion bulbs, remyelination and a reduced motor conduction velocity of around 30m/s similar to patients. Previously, it had been shown that T-lymphocytes and macrophages play a crucial role during pathogenesis in peripheral nerves of P0+/- mice. Both, T-lymphocytes and macrophages increase in number in the endoneurium and deletion of T-lymphocytes or deletion of a macrophage-directed cytokine ameliorates the disease. In this study the monocyte chemoattractant protein-1 (MCP-1) was identified as an early regulated cytokine before onset of disease is visible at the age of six months. MCP-1 mRNA and protein expression could be detected in femoral quadriceps and sciatic nerves of P0+/- mice already at the age of one month but not in cutaneous saphenous nerves which are never affected by the disease. MCP-1 was shown to be expressed by Schwann cells and to mediate the immigration of immune cells into peripheral nerves. Deletion of MCP-1 in P0+/- mice accomplished by crossbreeding P0 and MCP-1 deficient mice revealed a substantial reduction of immune cells in peripheral nerves of P0+/-/MCP-1+/- and P0+/-/MCP-1-/- mice at the age of six months. In twelve months old mice reduction of immune cells in peripheral nerves is accompanied by amelioration of demyelinating disease in P0+/-/MCP-1+/- and aggravation of demyelinating disease in lumbar ventral roots of P0+/ /MCP-1-/- mice in comparison to P0+/ /MCP 1+/+ mice. Furthermore, activation of the MEK1/2-ERK1/2 signalling cascade could be demonstrated to take place in Schwann cells of affected peripheral nerves of P0+/- mice overlapping temporarily and spatially with MCP-1 expression. An animal experiment using a MEK1/2-inhibitor in vivo, CI-1040, revealed that upon reduction of ERK1/2 phosphorylation MCP-1 mRNA expression is diminished suggesting that the activation of the MEK1/2-ERK1/2 signalling cascade is necessary for MCP-1 expression. Additionally, peripheral nerves of P0+/- mice showing reduced ERK1/2 phosphorylation and MCP-1 mRNA expression also show reduced numbers of macrophages in the endoneurium. This study shows a molecular link between a Schwann cell based mutation and immune cell function. Inhibition of the identified signalling cascade might be a putative target for therapeutic approaches.}, subject = {Schwann-Zelle}, language = {en} }