Leptin Induces Cyclin D1 Expression and Proliferation of Human Nucleus Pulposus Cells via JAK/STAT, PI3K/Akt and MEK/ERK Pathways
Figure 1
Morphology, immunofluorescence characterization and real-time quantitative PCR validation of primary cultured human NP cells.
(A) Phase-contrast photomicrograph of primary NP cells cultured in vitro for about 1 week, just before reaching complete confluence. Original magnification, ×40. (B) Real-time RT-PCR analysis of novel NP cell marker gene CA12 in NP cells, chondrocytes, NP and AF. Real-time RT-PCR analysis was performed in triplicate and the expression levels of CA12 mRNAs were normalized to GAPDH mRNAs. Error bars represent standard deviration. (C) Fluorescence microscopy images showing collagenase type II were observed in NP cells. Nuclei were stained with DAPI, shown in blue. Images were acquired using laser scanning confocal microscopy under a 40× objective. (D) Fluorescence microscopy images showing cytokeratin 19 were observed in NP cells. Nuclei were stained with DAPI, shown in blue. Images were acquired using laser scanning confocal microscopy under a 40× objective. Real-time RT-PCR analysis of novel negative NP cell marker gene IBSP (E) and FBN1 (F) in NP cells, chondrocytes, NP and AF. Real-time RT-PCR analysis was performed in triplicate and the expression levels of IBSP and FBN1 mRNAs were normalized to GAPDH mRNAs.