The Yin and Yang of Autosomal Recessive Primary Microcephaly Genes: Insights from Neurogenesis and Carcinogenesis.

The stem cells of neurogenesis and carcinogenesis share many properties, including proliferative rate, an extensive replicative potential, the potential to generate different cell types of a given tissue, and an ability to independently migrate to a damaged area. This is also evidenced by the common molecular principles regulating key processes associated with cell division and apoptosis. Autosomal recessive primary microcephaly (MCPH) is a neurogenic mitotic disorder that is characterized by decreased brain size and mental retardation. Until now, a total of 25 genes have been identified that are known to be associated with MCPH. The inactivation (yin) of most MCPH genes leads to neurogenesis defects, while the upregulation (yang) of some MCPH genes is associated with different kinds of carcinogenesis. Here, we try to summarize the roles of MCPH genes in these two diseases and explore the underlying mechanisms, which will help us to explore new, attractive approaches to targeting tumor cells that are resistant to the current therapies.

Regulatory action of charred Gossamer urocteae on the functions of mouse oral fibroblasts.

OBJECTIVE: To explore the influence of charred Gossamer urocteae (CGU) on the functions of primary cultured mouse oral fibroblasts and reveal its mechanism in wound healing. METHODS: CGU was extracted with different solvents and ethanol extract (EE), ethyl acetate fraction (EF), n-butanol fraction (BF) and aqueous fraction (AF) were obtained. The effects of different fractions on the proliferation, matrix metalloproteinase-2,9 (MMP-2,9) activities, synthesis of collagen and tissue inhibitor of metalloproteinase 1 (TIMP-1) in the mouse oral fibroblasts were determined by MTT, gelatin zymography, chloramine-T method, and enzyme-linked immunosorbent assay (ELISA) respectively. RESULTS: EE, EF and BF at high concentrations could significantly inhibit proliferation of fibroblasts (P<0.05 or P<0.01), and at low concentrations EF and BF could promote proliferation of fibroblasts, and BF and AF could significantly inhibit collagen synthesis (P<0.05 or P<0.01). EE, EF and AF at high concentrations could significantly increase the MMP-9 activity, and BF and AF could significantly inhibit synthesis of TIMP-1. CONCLUSION: CGU at high concentrations can inhibit the proliferations of fibroblasts and synthesis of collagen, and in healing of wound, CGU at high concentrations possibly has the functions of anti-fibrosis and anti-scar, and the mechanism to promote degradation of collagen is possibly related to the increase in MMP-9 activity and the inhibition of TIMP-1 synthesis.

[Regulation of calculus bovis on the function of mice oral fibroblasts].

To explore the influence of calculus bovis on the function of primary cultured mice oral fibroblasts, we determined the effects of calculus bovis on the fibroblast proliferation, collagen production, matrix metalloproteinases-2, -9 activities and tissue inhibitor of metalloproteinase-1 production by MTT assay, chloramine T method, gelatin zymography and enzyme-linked immunosorbent assays respectively. The results showed that calculus bovis could significantly inhibit the proliferation of fibroblasts and collagen synthesis in a concentration dependent manner, could significantly (P<0.05) suppress matrix metalloproteinases-2 activity and very significantly (P<0.01) inhibit the production of tissue inhibitor of metalloproteinase-1. In conclusion, the major function of calculus bovis in the process of ulcer healing is not to promote tissue regeneration, the mechanism that calculus bovis inhibits collagen synthesis may be partly due to its ability to very significantly (P<0.01) suppress the production of tissue inhibitor of metalloproteinase-1.