Gene network analysis on the effect of Viscum album var. coloratum in T cells stimulated with anti-CD3/CD28 antibodies

Activated T cells induce proliferation of oligodendrocyte progenitor cells via release of vascular endothelial cell growth factor-A

Neuroinflammatory diseases such as multiple sclerosis are characterized by infiltration of lymphocytes into the central nervous system followed by demyelination and axonal degeneration. While evidence suggests that activated T lymphocytes induce neurotoxicity and impair function of neural stem cells, the effect of T cells on oligodendrocyte progenitor cells (OPCs) is still uncertain, partly due to the difficulty in obtaining human OPCs. Here we studied the effect of activated T cells on OPCs using OPCs derived from human hematopoietic stem cells or from human fetal brain. OPCs were exposed to supernatants (sups) from activated T cells. Cell proliferation was determined by EdU incorporation and CellQuanti-Blue assays. Surprisingly, we found that sups from activated T cells induced OPC proliferation by regulating cell cycle progression. Vascular endothelial growth factor A (VEGF-A) transcripts were increased in T cells after activation. Immunodepletion of VEGF-A from activated T cell sups significantly attenuated its effect on OPC proliferation. Furthermore, VEGF receptor 2 (VEGFR2) was expressed on OPCs and its inhibition also attenuated activated T cell-induced OPC proliferation. Thus, activated T cells have a trophic role by promoting OPC proliferation via the VEGFR2 pathway.

European Viscum album: a potent phytotherapeutic agent with multifarious phytochemicals, pharmacological properties and clinical evidence

Viscum albumL. or European mistletoe (Loranthaceae), a semi-parasitic shrub, has been used as a traditional medicine in Europe for centuries to treat various diseases like cancer, cardiovascular disorder, epilepsy, infertility, hypertension and arthritis.

Korean mistletoe lectin promotes proliferation and invasion of trophoblast cells through regulation of Akt signaling

Recently, Viscum album var. coloratum agglutinin (VCA) was shown to have various effects on cancer cells. However, most researchers are focused on high concentrations (1-1000 ng/ml) of VCA and its anti-cancer effects. Therefore, we wanted to know whether low concentrations of VCA have an effect on proliferation and invasion of human trophoblast cells (HTR-8/SVneo cell line). Cell proliferations at low concentration of VCA (1-10 pg/ml) were increased over 2-fold relative to the control. Also, gelatinolytic activities of matrix metalloproteinase-2 were increased after VCA treatment, while TIMP-1 expression was reduced. Furthermore, the expression of integrin subunits α5 and β1 were increased 1.5-fold when cells were treated with low dose of VCA (10 pg/ml). Lastly, VCA was able to promote trophoblast invasion through activation of the Akt signaling pathway. In conclusion, low concentrations of VCA can stimulate the ability of trophoblast cells to invade through the extracellular matrix in vitro.