ENHANCEMENT OF NIH3T3 CELL PROLIFERATION BY EXPRESSING MACROPHAGE COLONY STIMULATING FACTOR IN NUCLEI

Objective: To explore the effects of nuclear M-CSF on the process of tumorigenesis. Methods: Functional part of M-CSF cDNA was inserted into an eukaryotic expression plasmid pCMV/myc/nuc, which can add three NLS to the C-terminal of the expressed protein and direct the protein into the cell nuclei. The constructed plasmid was transferred into NIH3T3 cells and the cell clones were selected by G-418 selection. Cell clones stable expressing target protein were identified by RT-PCR, ABC immunohistochemistry assayand Western blot. Cell growth kinetics analyses throughgrowth curves, cell doubling time, MTT test and anti-sense oligodeoxynucleotide (ASODN) inhibiting cell growth testwere performed to identify cells proliferation potential.Results: The transfected cells showed elevated proliferation potential over the control cells. Conclusion: Abnormalappearance of M-CSF in nucleus could enhance cellproliferation, which suggests that cytokine isoforms within cell nucleus might play transcription factor-like role.

IP10, KC and M-CSF Are Remarkably Increased in the Brains from the Various Strains of Experimental Mice Infected with Different Scrapie Agents

Activation of inflammatory cells and upregulations of a number of cytokines in the central nervous system(CNS)of patients with prion diseases are frequently observed.To evaluate the potential changes of some brain cytokines that were rarely addressed during prion infection,the levels of 17 different cytokines in the brain homogenates of mice infected with different scrapie mouse-adapted agents were firstly screened with Luminex assay.Significant upregulations of interferon gamma-induced protein 10(IP10),keratinocyte chemoattractant(KC)and macrophage colony stimulating factor(M-CSF)were frequently detected in the brain lysates of many strains of scrapie infected mice.The upregulations of those three cytokines in the brains of scrapie infected mice were further validated by the individual specific ELISA and immunohistochemical assay.Increased specific mRNAs of IP10,M-CSF and KC in the brains of scrapie infected mice were also detected by the individual specific qRT-PCRs and IP10-specific digital PCR.Dynamic analyses of the brain samples collected at different time points post infection revealed the time-dependent increases of those three cytokines,particularly IP10 during the incubation period of scrapie infection.In addition,we also found that the levels of IP10 in cerebral spinalfluid(CSF)of 45 sporadic Creutzfeldt–Jakob disease(sCJD)patients were slightly but significantly higher than those of the cases who were excluded the diagnosis of prion diseases.These data give us a better understanding of inflammatory reaction during prion infection and progression of prion disease.