Overexpression of circ_0002538 improves demyelination and symptoms of DPN.
(A) Intraoperative images showing the sciatic nerve after the injection of lentiviral solution. Scale bar: 1500 μm. (B) Eight weeks after the injection of lentiviral solution. We observed green fluorescence in the sciatic nerve under a fluorescence microscope. Scale bar: 200 μm. (C) Eight weeks after the injection of LV-circ_0002538, we examined the mRNA expression level of circ_0002538 in the sciatic nerve via RT-PCR (n = 4). Y-axis: fold changes in circ_0002538 expression compared with the vector side. (D) Immunofluorescence staining of MPZ showed that GFP+ cells also expressed MPZ. The arrows indicate the co-localized regions. (E, F) Eight weeks after the injection of lentiviral solution, the mechanical (E) and thermal (F) nociceptive thresholds were evaluated in the circ_0002538 group and the vector group (n = 20). (G, H) SNCV and MNCV were measured in the circ_0002538 group and the control group (n = 20). (I) The number of abnormal myelin sheaths in the circ_0002538 group, detected by transmission electron microscopy, was lower than that in the vector group (n = 4). Arrows indicate abnormal myelin sheaths. Scale bars: 5 μm. (J) Quantification of the ratio of myelin abnormalities in I. The data are given as the mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001, vs. vector side (paired t-test). DAPI: 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride; GFP: green fluorescent protein; MNCV: motor nerve conduction velocity; MPZ: myelin protein zero; SNCV: sensory nerve conduction velocity; TEM: transmission electron microscope.