Primary culture of choroid plexuses from neonate rats containing progenitor cells capable of differentiation

Effects of passage and cryopreservation on neurotrophic factor secretion from choroid plexus epithelial cells

The aim of the present study was to evaluate the effects of passage and cryopreservation of choroid plexus epithelial cells on their secretion of neurotrophic factors. Choroid plexus epithelial cells were cryopreserved and thawed following primary culture or passage cultured for up to two passages. The supernatant of primary, first/second passage and cryopreserved-thawed choroid plexus epithelial cells was collected when cells reached 80-90% confluence. ELISA was used to quantify brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), nerve growth factor (NGF) and ciliary neurotrophic factor (CNTF) levels in the cell supernatant. First passage and cryopreserved-thawed cells secreted less BDNF and CNTF compared with primary cultured cells and increased levels of these two factors compared with second passage cells, and increased levels of GDNF and NGF compared with primary cultured and second passage cells (all P<0.05). Therefore, first passage culture decreased BDNF and CNTF secretion but increased NGF and GDNF compared with primary culture; second passage culture diminished neurotrophic factor secretion compared with first passage culture; and cryopreservation did not weaken the function of choroid plexus epithelial cells in secreting BDNF, GDNF, NGF and CNTF. The current study demonstrates that first passage and cryopreserved-thawed choroid plexus epithelial cells have an enhanced function to secrete neurotrophic factors including BDNF, GDNF, NGF and CNTF.

Secretion of BDNF and GDNF from free and encapsulated choroid plexus epithelial cells

Choroid plexus epithelial cells secrete numerous biologically active neurotrophic factors, which may be beneficial to the transplantation site. Encapsulated cells are often used in tissue transplantation. The present study was conducted to investigate the effect of encapsulation on the secretory function of choroid plexus epithelial cells. Neonatal rat choroid plexus epithelial cells were primarily cultured. After 9 days of culture, the cells were distributed into two groups, and one group of cells was encapsulated in vitro. The initial culture conditions such as cell numbers and medium volumes were the same. Supernatants in the free and encapsulated choroid plexus epithelial cells were collected at the time points of day 1 through day 7. Quantitative determination of the BDNF and GDNF levels was performed by enzyme-linked immunosorbent assay to assess the secretory function of the cells in the two forms. Statistical analyses were performed using a Student t test. P<0.05 was set to indicate statistical significance. A very similar secretion pattern was observed in both groups. In the first 4 days of encapsulation, the release of BDNF and GDNF in the encapsulated cells was significantly lower than that in the free cells, while the difference diminished after day 5. This in vitro study demonstrates that the secretion of BDNF and GDNF in encapsulated choroid plexus epithelial cells is different from that in non-encapsulated cells in the early stage of encapsulation treatment, whereas it is similar in the later stage.