OBJECTIVE To investigate the effects of targeted muscular injection of ciliary neurotrophic factor (CNTF) on the regeneration of injured peripheral nerves. METHODS The left sciatic nerves of 80 Sprague-Dawley rats were excised to form 6 mm defect and the two ends were bridged by silicone tubes, they were randomly divided into two groups, CNTF group and normal saline (NS) group. The CNTF group was given recombinant human CNTF, 1 mg/kg every other day for 30 days, and the NS group was given equal quantity of normal saline as NS group. The sciatic nerve functional index (SFI), electrophysiological assessment, morphometric analysis of axons, and choleratoxin horseradish peroxidase (CB-HRP) retrograde-labelling were measured postoperatively. RESULTS The SFI, electrophysiological parameters (nerve conduction velocity, latency and amplitude of compound muscle action potentials), myelinated axons counts, mean axons diameters and myelin sheath thickness, number of CB-HRP labelled ventral horn motor neurons of spinal cord were significantly higher in CNTF group than that of NS group. CONCLUSION Targeted muscular injection of CNTF can promote the regeneration of peripheral nerve and improve the nerve functional recovery.
Objective To observe the morphological changes and gene expression during the transdifferentiation of adult retinal pigment epith elial(RPE) cells into neuronal phenotype in vitro induced by retrovirus and ciliary neurotrophic factor (CNTF). Meothds The adult RPE cells derived from CRL 2302 were infected by retrovirus with green fluoresence protein(GFP)and then were transfected further by liposome mediated CNTF expressing plasmid.The cellular ability of producing CNTG,and the expression of CNTF, CNTF receptor (CNTFR), and signal transduction molecule janus tyrosine kinases (JAK) were detected by enzyme linked immunosorbent assay, immunohistochemical stainin gand Western blotting method. Results After infected by retrovirus, the configuration of adult RPE cells didnrsquo;t change much, but expressions of neurons and some glial cells markers likeneurofilament (NF) protein and glial fibraillary acidic protein (GFAP) were detected. After further transfected by CNTF expressing plasmid, RPE cells which expressed CNTF highly and continuously had differential neurocytes; the expression of CNTFR didnrsquo;t change, but the distribution position changed to the cell membrane; expression of signal transduction molecule JAK increased obviously. Conclusion The adult RPE cells may transdifferentiate into neurons induced by retrvirus and CNTF. The transdifferentiation may relate to CNTF-CNTFR-JAK signal transduction pathway. (Chin J Ocul Fundus Dis, 2006, 22: 400-403)
ObjectiveTo observe the morphological and functional changes of retinal degeneration in mice with CLN7 neuronal ceroid-lipofuscinosis, and the therapeutic effects of glial cell derived neurotrophic factor (GDNF) and/or ciliary neurotrophic factor (CNTF) based on neural stem cells (NSC) on mouse photoreceptor cells. MethodsA total of 100 CLN7 mice aged 14 days were randomly divided into the experimental group and the control group, with 80 and 20 mice respectively. Twenty C57BL/6J mice aged 14 days were assigned as wild-type group (WT group). Mice in control group and WT group did not receive any interventions. At 2, 4, and 6 months of age, immunohistochemical staining was conducted to examine alterations in the distribution and quantity of cones, rod-bipolar cells, and cone-bipolar cells within the retinal of mice while electroretinography (ERG) examination was utilized to record scotopic a and b-waves and photopic b-wave amplitudes. At 14 days of age, the mice in the experimental group were intravitreally injected with 2 μl of CNTF-NSC, GDNF-NSC, and a 1:1 cell mixture of CNTF-NSC and GDNF-NSC (GDNF/CNTF-NSC). Those mice were then subdivided into the CNTF-NSC group, the GDNF-NSC group, and the GDNF/CNTF-NSC group accordingly. The contralateral eyes of the mice were injected with 2 μl of control NSC without neurotrophic factor (NTF) as their own control group. At 2 and 4 months of age, the rows of photoreceptor cells in mice was observed by immunohistochemical staining while ERG was performed to record amplitudes. At 4 months of age, the differentiation of grafted NSC and the expression of NTF were observed. Statistical comparisons between the groups were performed using a two-way ANOVA. ResultsCompared with WT group, the density of cones in the peripheral region of the control group at 2, 4 and 6 months of age (F=285.10), rod-bipolar cell density in central and peripheral retina (F=823.20, 346.20), cone-bipolar cell density (F=356.30, 210.60) and the scotopic amplitude of a and b waves (F=1 911.00, 387.10) in central and peripheral retina were significantly decreased, with statistical significance (P＜0.05). At the age of 4 and 6 months, the density of retinal cone cells (F=127.30) and b-wave photopic amplitude (F=51.13) in the control group were significantly decreased, and the difference was statistically significant (P＜0.05). Immunofluorescence microscopy showed that the NSC transplanted in the experimental group preferentially differentiated into astrocytes, and stably expressed CNTF and GDNF at high levels. Comparison of retinal photoreceptor nucleus lines in different treatment subgroups of the experimental group at different ages: CNTF-NSC group, at 2 months of age: the whole, central and peripheral regions were significantly different (F=31.73, 75.06, 75.06; P＜0.05); 4 months of age: The difference between the whole area and the peripheral region was statistically significant (F=12.27, 12.27; P＜0.05). GDNF/CNTF-NSC group, 2 and 4 months of age: the whole (F=27.26, 27.26) and the peripheral area (F=16.01, 13.55) were significantly different (P＜0.05). In GDNF-NSC group, there was no statistical significance at all in the whole, central and peripheral areas at different months of age (F=0.00, 0.01, 0.02; P＞0.05). ConclusionsCLN7 neuronal ceroid-lipofuscinosis mice exhibit progressively increasing degenerative alterations in photoreceptor cells and bipolar cells with age growing, aligning with both morphological and functional observations. Intravitreal administration of stem cell-based CNTF as well as GDNF/CNTF show therapeutic potential in rescuing photoreceptor cells. Nevertheless, the combined application of GDNF/CNTF-NSC do not demonstrate the anticipated synergistic protective effect. GDNF has no therapeutic effect on the retinal morphology and function in CLN7 neuronal ceroid-lipofuscinosis mice.