Objective To investigate the effects of vascular endothelial growth factor C (VEGF-C) gene modified lymph nodes on promoting proliferation of lymphatic endothelial cells in the surrounding tissues. Methods Thirty-six Sprague Dawley rats, weighing 200.1-271.5 g, were randomly divided into 2 groups (n=18). After the in situ axillary lymph nodes transplantation models were established in both groups, 1.5 × 108 PFU Ad-VEGF-C-Flag and Ad-Flag were injected into the transplanted lymph nodes in experimental group and control group, respectively. At 3 days after injection, the axillary lymph nodes were harvested to observe the expression of Flag; at 1, 2, and 4 weeks after injection, the axillary lymph nodes and the surrounding tissues were harvested to observe the expression of Prxo-1 protein and to calculate the fluorescence density; at 2 and 4 weeks after injection, the absorbance (A) value of treated blood at 620 nm was calculated to observe lymphatic back-flow function improvement; the rats without treatment served as normal control group, and the rats with in situ axillary lymph nodes transplantation model served as blank control group. Results At 3 days after injection, the expression of Flag could be detected in experimental group and control group. The fluorescence density of Prox-1 protein in experimental group increased at 1, 2, and 4 weeks, and it was significantly higher than that in control group (P lt; 0.05). The A values of normal control group and blank control group were 0.539 ± 0.020 and 0.151 ± 0.007, respectively. The A values of experimental group and control group were 0.170 ± 0.011 and 0.168 ± 0.010 at 2 weeks, and 0.212 ± 0.016 and 0.197 ± 0.006 at 4 weeks, which were significantly lower than those of normal control group (P lt; 0.05), but no significant difference was found when compared with blank control group, and between the experimental group and control group (P gt; 0.05). Conclusion The VEGF-C gene modified lymph nodes can stimulate the proliferation of lymphatic endothelial cells in the surrounding tissues. However, it has no improved effect on lymphatic back-flow function in the affected limb.
Abstract In order to investigate the mechanism ofregeneration of lymphatic vessel, the regulatory control of various cell factors on the new born bovine lymphatic endothelial cell (NBLEC) was observed. The cell factors used for investigation were bFGF, TGFα, EGF, TNFα and IL-1α. The results showed that bFGF, TGFα and EGF could stimulate NBLEC proliferation and DNA synthesis in dosage-dependent pattern. Combined use of either two factorsdid not increase the effect, and bFGF could increase cell migration and improve the activity of tissue plasminogen activator (t-PA). TNFα and IL-α inhibited NBLEC regeneration and DNA synthesis but TNFα improved the activity of t-PA. It could be concluded that growth factor and inflammatory factor had differentrole on regeneration of NBLEC, such as cell proliferation, migration and t-PA activity. bFGF was the main factor which improved the regenerationof lymphatic endothelial cell.