Fig 1: SEMA3B transiently interrupts axonal adhesion to facilitate nmSC-nmA adhesion.a UMAP plot illustrating L1cam expression in iSCs and nmSCs. b FISH on transverse section of P28 sciatic nerve. Arrowheads indicate L1cam+Scn7a+SOX10+ nmSCs and arrows indicate L1cam-Scn7a-SOX10+ mSCs. The experiment was repeated 3 times on 3 mice. c STED image of the RB from P28 Plp1CreERT2;R26tdTOM sciatic nerves. The experiment was repeated 3 times on 3 mice. c’ Magnified view of the boxed area in (c) illustrating a high L1CAM expression level in the contacting area between TUJ1+ axons and TOM+ SC lamellipodia. Note the presence of L1CAM signals in TOM+ SC lamellipodia. d Drawing a line to calculate the fluorescence intensity across the section. e Quantification of the fluorescence intensities of TOM, TUJ1, and L1CAM signals. f Representative E14.5 DRG SNs cultured on Fc- and L1CAM-coated coverslips. g Quantification of the numbers of attached sensory neurons. n = 6 independent experiments for both group. h SCs purified from P0 sciatic nerves cultured on Fc- or L1CAM-coated coverslips. i Quantification of the numbers of attached SCs. n = 6 independent experiments for both groups. j Assay for mimicking the acute and chronic effect of SEMA3B on attached SNs and SCs on L1CAM-coated coverslip. k Images showing attached SNs under different conditions. l Quantification of the numbers of attached SNs under different conditions. n = 6 independent experiments for all groups. m Images showing attached SCs under different conditions. n Quantification of the numbers of attached SCs under different conditions. n = 6 independent experiments for all groups. o Schematic representation of the three biological events involved in RB assembly: nmA-nmA adhesion, nmA-nmA deadhesion, and nmA-nmSC adhesion. The corresponding molecular mechanisms are depicted. nmSC-derived SEMA3B interacts with axonal NRP1/L1CAM receptor complex to shift CAM-induced nmA-nmA adhesion to CAM-induced nmA-nmSC adhesion. The lower panel presents STED images illustrating the dynamic distribution patterns of CAM during the three events of RB assembly. All data are presented as mean ± SEM. **p < 0.01, *p < 0.05. Detailed statistics are provided in Supplementary Table 2. Source data are provided as a Source Data file.
Fig 2: Elevating SEMA3B expression level in SCs alleviates PN injury-induced pain.a UMAP visualization of SCs from scRNA-seq data in sham mice and nerve-injury mice. b Relative proportions of SC lineages in total SCs of sham mice and nerve-injury mice. c Dot plot showing expression levels of Scn7a, Sema3b, and L1cam in SCs of sham mice and nerve-injury mice. d Cartoon depicting that the distal part of the injury site is harvested for analysis. e Sema3b expression levels in SOX10+ SC following different days post ligation (dpl) of control mice. f Sema3b expression levels in SOX10+ SCs following different days post-ligation (dpl) of Sema3btgSC mice. Sema3b transcript levels demonstrated relatively stable after nerve injury. g Quantification using qPCR showing Sema3b transcript levels in sciatic nerves without injury (sham) and with 7 and 21 days post ligation (dpl). n = 6 mice for all groups. h–j Representative TEM images of the sciatic nerves from control and Sema3btgSC mice. Note that the contact area between nmSC lamellipodia and axons is significantly decreased in the RB of control mice after injury. In contrast, the deficient RB assembly is noticeably reduced in Sema3btgSC mice with injury. Asterisks and circles indicate axons that are adjacent and partially wrapped, respectively. Arrowheads indicate lamellipodia protruding into the endoneurial space. k Quantification of RBM indexes of control and Sema3btgSC mice without and with nerve crush. n = 6 mice for all groups. l Measurements of sensitivity to von Frey filaments in control and Sema3btgSC mice without and with nerve injury. n = 6 mice for all groups. m Measurements of sensitivity to hot laser in control and Sema3btgSC mice without and with nerve injury. n = 6 mice for all groups. All data are presented as mean ± SEM. **p < 0.01, *p < 0.05. Detailed statistics are provided in Supplementary Table 2. Source data are provided as a Source Data file.
Fig 3: SC-derived SEMA3B promotes localized axon deadhesion and CAM clearance.a STED images showing TUJ1 signals on axon bundles treated with Fc and SEMA3B. Arrowheads indicate axonal beading. b Fasciculation index is calculated as the axonal area divided by the total area. c Quantification of the fasciculation indexes for axon bundles treated with Fc and SEMA3B. n = 6 axon shafts from 3 DRGs for both groups. d KEGG pathway analysis of up-regulated DEGs in nmSN. Pathway enrichment was analyzed by a two-tailed Wald test with Benjamini-Hochberg correction (FDR-adjusted p-value < 0.05 and |log₂ fold change|> 0.25). e Dot plot illustrating genes in the cell adhesion molecules pathway. f, g STED images of P7 Plp1CreERT2;R26tdTom RBs. Dotted lines demarcate RB boundaries. Asterisks denote axons ensheathed by TOM+ mSCs. The experiment was repeated 3 times on 3 mice. f’, g’ Magnified views of the boxed areas in (f) and (g). Dotted lines demarcate unmyelinated axon boundaries. Arrowheads indicate lamellipodia undergoing separating fasciculated axons. The asterisk in (g’) denotes an axon wrapped by SC lamellipodia, with strong CDH2 signals in the contact region. h STED images showing TUJ1 signals on axon bundles. i Quantification of the fasciculation indexes for axon bundles with SEMA3B or SEMA3B+Dynasore treatment. n = 6 axons bundles from 3 DRGs for both groups. j, k L1CAM and CDH2 particles on the membrane of sensory axon shafts from E14.5 DRG. l Quantification of artificial fluorescence intensity of L1CAM on the membrane of sensory axon shafts. n = 7 axon bundles from 3 DRGs for all groups. m Quantification of artificial fluorescence intensity of CDH2 on the membrane of sensory axon shafts. n = 6 axon bundles from 3 DRGs for all groups. n–p STED images of the RBs from P7 control, Sema3btgSC, and Sema3b∆SC mice. Dotted lines delineate the assumed RB boundaries. q Quantification of the numbers of L1CAM particles per RB. n = 6 RBs from 3 mice for all groups. r Schematic summary: nmSC-derived SEMA3B induces the endocytosis of axonal CAMs, leading to axonal segregation. All data are presented as mean ± SEM. **p < 0.01, *p < 0.05. Detailed statistics are provided in Supplementary Table 2. Source data are provided as a Source Data file.
Fig 4: Elevating SEMA3B expression level in SCs accelerates RB assembly.a Schematic illustration of the strategy for generating Sema3btgSC mice. b, c FISH on the sciatic nerve showing an increased Sema3b expression level in SOX10+ SCs of P14 Sema3btgSC mice. Arrowheads and arrows in b indicate Sema3b+SOX10+ SCs and Sema3b-SOX10+ SCs. Note that in Sema3btgSC mice, Sema3b expression is ubiquitous in all SOX10+ SCs, which concurrently express TOM. d Quantification of Sema3b transcript level with qPCR in the sciatic nerve of P14 control (n = 6) and Sema3btgSC(n = 6) mice. e, f Representative TEM images of the sciatic nerve from P7 and P28 control and Sema3btgSC mice. Asterisks and circles denote axons that are adjacent and partially wrapped, respectively. Arrowheads indicate lamellipodia protruding into the endoneurial space. g Quantification of the RBM indexes from P7 and P28 control (n = 6 for both P7 and P28) and Sema3btgSC (n = 6 for both P7 and P28) mice. All data are presented as mean ± SEM. *p < 0.05. Detailed statistics are provided in Supplementary Table 2. Source data are provided as a Source Data file.
Fig 5: SC-derived SEMA3B regulates RB assembly.a Quantitative real-time PCR (qPCR) analysis of Sema3b mRNA expression in sciatic nerves across postnatal development (P0, P7, P14, P28, and P60). n = 3 sciatic nerves per time point. b Transversal section of the P14 sciatic nerve showing that SEMA3B+SOX10+MBP- SCs ensheath unmyelinated TUJ1+ axons. The arrowhead and arrow indicate SEMA3B+SOX10+MBP- nmSCs and SEMA3B-SOX10+MBP+ mSCs, respectively. The experiment was repeated 3 times on 3 mice. c, d Representative TEM images of the sciatic nerve from P60 control and Sema3b∆SC mice. nmSC lamellipodia are pseudo-colored to highlight their locations. Asterisks denote adjacent axons and circles denote partially wrapped axons. Arrowheads indicate lamellipodia protruding into the endoneurial space. The experiment was repeated 3 times on 3 mice. e, f Lateral views of 3D-reconstructed RB from the sciatic nerve of P60 control and Sema3b∆SC mice. g Quantification of the RBM indexes from P60 control (n = 7) and Sema3b∆SC (n = 7) mice. h Quantification of the RBM indexes from P7 (n = 5 for both groups) and P28 Sema3bi∆SC (n = 5 for both groups) mice with coil (CO) and tamoxifen (TM) treatment at P0. i Measurements of sensitivity to laser heat in control (n = 6 for all groups) and Sema3b∆SC (n = 7 for all groups) mice. j Measurements of sensitivity to von Frey filaments in control (n = 6) and Sema3b∆SC (n = 6) mice. All data are presented as mean ± SEM. **p < 0.01, *p < 0.05, ns not significant. Detailed statistics are provided in Supplementary Table 2. Source data are provided as a Source Data file.
Supplier Page from R&D Systems, a Bio-Techne Brand for Recombinant Mouse Semaphorin 3B Fc Chimera Protein, CF