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Updated: Aug 5, 2026
In Vitro Myelination of Peripheral Axons in a Coculture of Rat Dorsal Root Ganglion Explants and Schwann Cells
Published on: February 10, 2023
Case Report: Schwann cell reprogramming and PDGF-driven nerve hypertrophy in an NF1 patient with CIDP-like
Fei Wang1, Wenqian Cao2, Jiaye Lu1
1Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
Background And Aims:
Differentiating neoplastic proliferation from inflammatory fibrosis in peripheral nerve hypertrophy is critical. We report a patient with a neurofibromatosis type 1 (NF1) deletion exhibiting extreme diffuse nerve enlargement and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)-like autoimmunity. This study aims to elucidate the underlying endoneurial fibrotic mechanism, specifically focusing on the signaling networks between Schwann cells (SCs) and fibroblasts.
Methods:
Single-cell RNA sequencing was performed on a biopsied sural nerve to profile the cellular and transcriptomic landscape. Intercellular interactome and pseudotime trajectory analyses were utilized to map molecular evolution and signaling crosstalk.
Results:
Transcriptomic profiling revealed that SCs-which normally maintain myelin around axons and support peripheral nerve function-were pathologically entrapped in a dedifferentiated state. Serving as a genetic primer, the NF1 deletion lowered the threshold for SC reprogramming, a vulnerability that was subsequently unleashed by a severe autoimmune infiltrate consisting of macrophages and T cells. These reprogrammed SCs abandoned myelin-maintaining genes, such as MPZ, to acquire a pro-fibrotic phenotype. Through a coordinated platelet-derived growth factor (PDGF) dual-axis network involving PDGFC-PDGFRA and PDGFD-PDGFRB, the entrapped SCs exclusively secreted PDGF ligands that potently activated endoneurial fibroblasts and vascular mural cells. This persistent paracrine signaling orchestrated excessive extracellular matrix deposition, driving a massive expansion of the endoneurial interstitium and the formation of classic "onion bulbs".
Interpretation:
Our data suggest that the macroscopic hypertrophic changes observed in this specific clinical presentation may reflect an aberrant, immune-triggered fibrotic cascade-where autoimmune leukocyte infiltration continuously drives stromal overgrowth-complementing rather than entirely precluding the classical RAS/MAPK-driven neoplastic SC hyperproliferation. Furthermore, within the limitations of this pilot evaluation, characterizing this potential SC-fibroblast crosstalk indicates that the PDGF signaling pathway may warrant further investigation as a candidate translational therapeutic target for refractory hypertrophic neuropathies.
