Understanding limb development not only gives insights into the outgrowth and differentiation of the limb, but also has clinical relevance. Limb development begins with two paired limb buds (forelimb and hindlimb buds), which are initially undifferentiated mesenchymal cells tipped with a thickening of the ectoderm, termed the apical ectodermal ridge (AER). As a transitional embryonic structure, the AER undergoes four stages and contributes to multiple axes of limb development through the coordination of signalling centres, feedback loops, and other cell activities by secretory signalling and the activation of gene expression. Within the scope of proximodistal patterning, it is understood that while fibroblast growth factors (FGFs) function sequentially over time as primary components of the AER signalling process, there is still no consensus on models that would explain proximodistal patterning itself. In anteroposterior patterning, the AER has a dual-direction regulation by which it promotes the sonic hedgehog (Shh) gene expression in the zone of polarizing activity (ZPA) for proliferation, and inhibits Shh expression in the anterior mesenchyme. In dorsoventral patterning, the AER activates Engrailed-1 (En1) expression, and thus represses Wnt family member 7a (Wnt7a) expression in the ventral ectoderm by the expression of Fgfs, Sp6/8, and bone morphogenetic protein (Bmp) genes. The AER also plays a vital role in shaping the individual digits, since levels of Fgf4/8 and Bmps expressed in the AER affect digit patterning by controlling apoptosis. In summary, the knowledge of crosstalk within AER among the three main axes is essential to understand limb growth and pattern formation, as the development of its areas proceeds simultaneously.
Animals ; Apoptosis ; Body Patterning ; Bone Morphogenetic Proteins/biosynthesis* ; Developmental Biology ; Ectoderm/metabolism* ; Extremities/embryology* ; Fibroblast Growth Factor 10/metabolism* ; Fibroblast Growth Factors/biosynthesis* ; Gene Expression Regulation ; Hedgehog Proteins/biosynthesis* ; Homeodomain Proteins/biosynthesis* ; Mesoderm/metabolism* ; Mice ; Signal Transduction ; Wnt Proteins/biosynthesis*

Cell Line ; Epidermal Growth Factor ; biosynthesis ; genetics ; Fibroblast Growth Factor 2 ; biosynthesis ; genetics ; Hepatocytes ; metabolism ; Humans ; Interleukin-10 ; pharmacology ; Platelet-Derived Growth Factor ; pharmacology ; Proto-Oncogene Proteins c-sis ; RNA, Messenger ; biosynthesis ; genetics

To clone KGF-2 gene, get hKGF-2 protein and detemine its activity. The cNDA of human KGF-2 was isolated from fetal lung by RT-PCR and cloned into pBV220 plasmid. The recombinant pBV220-hKGF-2 plasmid was transformed into E. coli (BL21), induced at 42 degrees C for the expression of hKGF-2. Recombinant human KGF-2 was purified from the ultrasonic-treated BL21 by heparin-Sepharose CL-6B treated column chromatography and cation exchange column chromatography. MTT method was used for the determination of its biological activity. SDS-PAGE showed that rhKGF-2 was expressed in E. coli BL21 as soluble protein of approximately 20kD. The rhKGF-2 protein can stimulate the proliferation of NIH3T3 cells significantly from 1 ng/mL to 10 ng/mL. HKGF-2 cDNA wasclned and highly expressed in E. coli BL21 and the purified rhKGF-2 showed the mitogenic activity on NIH3T3 cells.
Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Fetus ; Fibroblast Growth Factor 10 ; biosynthesis ; genetics ; isolation & purification ; Genetic Vectors ; genetics ; Humans ; Lung ; chemistry ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification

This study is to investigate the effect of recombinant hFGF-10 adenovirus on the proteome of HaCat cells, and to speculate further the possible mechanism of the effect of hFGF-10 on HaCat cells via differentially expressed proteins identified. Two-dimensional gel electrophoresis (2-DE) combined with tandem time-of-flight mass spectrometry was applied to identify the differentially expressed protein spots on the 2-DE maps of the whole-cell proteins from Ad infected and rAd-hFGF-10 infected HaCat cells. The mRNA and protein levels of the differentially expressed proteins were confirmed with semi-quantitative RT-PCR and Western blotting. The results showed that the 2-DE maps with high resolution were obtained, and four selected differentially expressed proteins involved in cell apoptosis, cytoskeleton regulation and protein degradation were identified with MALDI-TOF/TOF. The mRNA and protein levels of one of the differentially expressed proteins, VDAC2, were up-regulated in HaCat cells infected with the recombinant hFGF-10 adenovirus. The differentially expressed protein, VDAC2, may be related to the bioactivities of hFGF-10.
Adenoviridae ; genetics ; Cell Line ; Electrophoresis, Gel, Two-Dimensional ; Fibroblast Growth Factor 10 ; genetics ; metabolism ; Humans ; Keratinocytes ; cytology ; metabolism ; Proteomics ; methods ; RNA, Messenger ; metabolism ; Recombinant Proteins ; metabolism ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Transfection ; Up-Regulation ; Voltage-Dependent Anion Channel 2 ; biosynthesis ; metabolism