OBJECTIVETo assess how trace element selenium and B27 supplements affect the neural stem cell (NSc) differentiation in vitro.

METHODSThe development and differentiation of NSc from the newborn rat were observed with primary culture and subculture during treating by sodium-selenite, and selenium-methyl-cysteine (SMC). The immunocytochemistry techniques were used to identify the NSc and mature protein expression with neuron marker beta-tubulin, astrocyte marker GFAP, and oligodendrocyte marker CNPase. The neurosphere morphology and neurite outgrowth were observed.

RESULTSAdding the complete B-27 serum-free supplement, Selenium could promote the neurosphere viability, development and differentiation. Without selenium and B-27, neurosphere could not survive and differentiate. Without B-27 in the medium but there containing selenium, the neurosphere could promote the viability and development into neuron, astrocyte and oligodendrocyte, as compared with the no-containing B-27 and selenium groups, these differentiated cells might have more quantity, more branches and better morphological nerve net. The count of the neuron, astrocyte and oligodendrocyte was 11.2/Hp, 16.1/Hp and 9.3/Hp.

CONCLUSIONSThe selenium should be very important for neural stem cells' survival. Selenium could promote the neurosphere cells differentiation and development.

Animals ; Animals, Newborn ; Cell Differentiation ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Culture Media, Serum-Free ; pharmacology ; Cysteine ; analogs & derivatives ; pharmacology ; Female ; Glial Fibrillary Acidic Protein ; metabolism ; Immunohistochemistry ; Male ; Neurons ; cytology ; drug effects ; metabolism ; Organoselenium Compounds ; pharmacology ; Rats ; Rats, Wistar ; Selenium ; pharmacology ; Selenocysteine ; analogs & derivatives ; Sodium Selenite ; pharmacology ; Stem Cells ; cytology ; drug effects ; metabolism ; Tubulin ; metabolism

OBJECTIVEHuman selenoprotein P (HSelP) is unique protein that contains 10 selenocysteines encoded by 10 inframe UGA, which typically function as stop codon. The function of HSelP remains unclear, in part due to the inability to express it by gene recombinant technique. This study is to investigate expression and purification of recombinant HSelP in prokaryotic expression system, and its activity to induce apoptosis in vitro.

METHODSThe shorter HSelP isoform was cloned. After the selenocysteine (SeCys) at 40th position from N terminus of the HSelP shorter isoform was mutated into cysteine by PCR, it was expressed in E. coli. The expressed product was purified with DEAE column and identified by Western blot. Subsequently, its function on induction of mitochondrial apoptotic activity was studied.

RESULTSThe mutant HSelP shorter isoform expressed in prokaryotic system was purified by DEAE column to 90% homogeneity. The purified product, HSelP280m, induced the opening of mitochondrial permeability transition pore (PTP) and decreased the transmembrane potential in a dose-dependent manner. These events could be abolished by PTP specific inhibitors.

CONCLUSIONHSelP280m can induce the opening of mitochondrial PTP, which provides a basis for investigating the structure and function of recombinant HSelP.

Animals ; Apoptosis ; drug effects ; Cloning, Molecular ; Cysteine ; genetics ; Escherichia coli ; metabolism ; Humans ; Ion Channels ; drug effects ; Male ; Membrane Potentials ; drug effects ; Mice ; Mice, Inbred BALB C ; Mitochondria, Liver ; physiology ; Mitochondrial Membrane Transport Proteins ; Mutation ; Protein Isoforms ; Proteins ; genetics ; metabolism ; pharmacology ; Selenium ; Selenocysteine ; genetics ; Selenoprotein P ; Selenoproteins