Endothelium in vitro:A review of human vascular endothelial cell lines for blood vessel-related research

Endothelial cells (EC) are currently used as in vitro model systems for various physiological and pathological processes, especially in angiogenesis research. Primary EC have a limited lifespan and display characteristics that differ from batch to batch due to their multidonor origin. In recent years many groups have established EC lines. This Review gives an overview of the advantages and disadvantages of currently available vascular EC lines. Its aim is to help the investigator to decide which cell line matches his or her research goal best. Truly immortalized cell lines are generally better characterized and more stable in their endothelial traits than EC that were given an extended life span. Presently the best characterized macro- and micro-vascular EC lines are EA.hy926 and HMEC-1, respectively.</p

Combination of vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP) to improve angiogenic gene therapy

To improve current angiogenic gene therapy with a vascular endothelial growth factor (VEGF)-encoding plasmid (Baumgartner et al. Circulation 1998; 97: 1114-23 [1]; Kusumanto et al. Fifth Annual Meeting of the American Society of Gene Therapy, Boston, 2002, Abstr. 621 [2]), we have generated a combination plasmid, encoding the VEGF gene and the thymidine phosphorylase (TP, also known as platelet-derived endothelial growth factor (PD-ECGF) or gliostatin (GLS)) gene: phVEGF165-TP.MB. Upon transfection in COS-7 cells both gene products were expressed and functional as shown by Western blots, ELISAs and bioassays. Culture supernatants of COS-7 cells transfected with this plasmid were able to induce endothelial proliferation. In an in vitro angiogenesis assay with recombinant proteins, TP was able to increase VEGF-induced tube formation. The phVEGF165-TP.MB plasmid is therefore a promising candidate for in vivo angiogenesis studies.</p

Combination of vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP) to improve angiogenic gene therapy

To improve current angiogenic gene therapy with a vascular endothelial growth factor (VEGF)-encoding plasmid (Baumgartner et al. Circulation 1998; 97: 1114-23 [1]; Kusumanto et al. Fifth Annual Meeting of the American Society of Gene Therapy, Boston, 2002, Abstr. 621 [2]), we have generated a combination plasmid, encoding the VEGF gene and the thymidine phosphorylase (TP, also known as platelet-derived endothelial growth factor (PD-ECGF) or gliostatin (GLS)) gene: phVEGF165-TP.MB. Upon transfection in COS-7 cells both gene products were expressed and functional as shown by Western blots, ELISAs and bioassays. Culture supernatants of COS-7 cells transfected with this plasmid were able to induce endothelial proliferation. In an in vitro angiogenesis assay with recombinant proteins, TP was able to increase VEGF-induced tube formation. The phVEGF165-TP.MB plasmid is therefore a promising candidate for in vivo angiogenesis studies.</p

Imaging retinal inflammatory biomarkers after intravitreal steroid and anti-VEGF treatment in diabetic macular oedema

PURPOSE: To evaluate changes of specific retinal imaging biomarkers [intraretinal hyper-reflective retinal spots: HRS ; subfoveal neuroretinal detachment: SND; and increased foveal autofluorescence: IFAF after intravitreal steroid or anti-vascular endothelial growth factor treatment in diabetic macular oedema (DME)] as possible indicators of retinal inflammatory condition.METHODS: Retrospective analysis of images and clinical charts of 49 eyes (49 patients) with DME treated with intravitreal dexamethasone (dexamethasone, 23 eyes) or intravitreal ranibizumab (ranibizumab, 26 eyes). All patients had fundus colour photograph, spectral domain optical coherence tomography (SD OCT) and fundus autofluorescence (FAF), best-corrected visual acuity (BCVA) and microperimetry recorded before and 1 month after the end of treatment. Central macular thickness (CMT), number of HRS and presence of SND were evaluated by SD OCT. Fundus autofluorescence images were evaluated for area of (IFAF). Retinal sensitivity within 4\ub0 and 12\ub0 from fovea was quantified by microperimetry. Changes in morphologic and functional parameters were assessed, and correlation was performed by Pearson's correlation. RESULTS: Best-corrected visual acuity and CMT improved in all patients, (p < 0.05, for both groups). Mean number of HRS decreased after both treatments (p < 0.0001). Subfoveal neuroretinal detachment resolved in 85.7% dexamethasone-treated eyes (p = 0.014) and in 50% ranibizumab-treated eyes (p = 0.025). Mean IFAF area decreased in both groups, (p < 0.0001, for both). A significantly higher decrease in CMT was observed in dexamethasone- versus ranibizumab-treated eyes, (p = 0.032). In dexamethasone group, higher number of HRS at baseline and larger IFAF were correlated with higher increase in retinal sensitivity; eyes with SND at baseline had major decrease in CMT versus those without SND, (p = 0.003). CONCLUSION: Higher number of HRS, larger area of IFAF and presence of SND may indicate a prevalent inflammatory condition in DME with specific response to targeted treatment