Figure 3

CXCR4 expression patterns in DRG sensory neurons. A-H: Confocal analysis of DRG isolated from non-diabetic CXCR4-eGFP mice fed with regular diet (RD) showing co-localization of CXCR4-eGFP in green with either CGRP (red) (B and F) or IB4 (purple) (C and G). The majority of DRG sensory neurons expressing CXCR4-eGFP are IB4 positive (C and G, arrows). Quantification: the percentage of CXCR4-eGFP positive cells expressing IB4 was 32.8 ± 6.5% (n = 9) compared to the percentage of CXCR4-eGFP positive cells expressing CGRP 1.78 ± 1.78% (n = 7). Values are expressed as means +/− SE% (p <0.001). I-P: Confocal analysis of DRG isolated from diabetic CXCR4-eGFP mice fed with High Fat Diet (HFD). CXCR4-eGFP reporter gene transcriptional activity appeared to be decreased in HFD induced diabetic DRG (I-P). Quantification: the percentage of IB4 positive DRG expressing CXCR4-EGFP in RD was 32.8 ± 6.5% (n = 9) compared to 1.0 ± 0.73% (n = 9) in HFD mice. Similarly, the percentage of CGRP positive DRG neurons expressing CXCR4-eGFP was also reduced in HFD-induced mice compared to RD non diabetic mice. Indeed, the percentage of CGRP positive DRG expressing CXCR4-EGFP in RD was 1.78 ± 1.78% (n = 7) compared with the 0.42 ± 0.42 (n = 9) in HFD DRG neurons. Values are expressed as means ± SE% (p <0.001). (Magnification 20x (scale bar 250 μm) in A-D and I-L; magnification 40x (scale bar 50 μm) in E-H and M-P). r: dorsal root.