Figure 9.

The absence of SPARC inhibits the BDNF/TrkB signaling pathway at the L2/3 level in spinal cord.

(A) Immunofluorescence staining of βIII-tubulin (green) with BDNF (red). Lower BDNF expression was observed in SPARC-null mice compared with WT mice in the whole spinal cord in neurons. (B) Immunofluorescence staining of Iba1 (green) with BDNF (red). Lower BDNF expression was observed in SPARC-null mice compared with WT mice in the whole spinal cord in microglia. Scale bars: 20 µm. (C) Western blot and quantitative analysis of BDNF and TrkB. Data are normalized to β-actin and shown as mean ± SD (n = 3 mice in each group). **P < 0.01, ****P < 0.0001 (Student’s t-test). BDNF: Brain-derived neurotrophic factor; SPARC: secreted protein, acidic and rich in cysteine; TrkB: tropomyosin related kinase B; WT: wild-type.