Prolonged propagation of rat neural stem cells relies on inhibiting autocrine/paracrine bone morphogenetic protein and platelet derived growth factor signals

Continuous expansion of rat neural stem cell lines has not been achieved due to proliferation arrest and spontaneous differentiation in vitro. In the current study, neural precursor cells derived from the subventricular zone of adult rats spontaneously underwent astroglial and oligodendroglial differentiation after limited propagation. This differentiation was largely induced by autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signals. The results showed that, by inhibiting bone morphogenetic protein and platelet derived growth factor signals, adult rat neural precursor cells could be extensively cultured in vitro as tripotent stem cell lines. In addition to adult rat neural stem cells, we found that bone morphogenetic protein antagonists can promote the proliferation of human neural stem cells. Therefore, the present findings illustrated the role of autocrine or paracrine bone morphogenetic protein and platelet derived growth factor signaling in determining neural stem cell self-renewal and differentiation. By antagonizing both signals, the long-term propagation of rat neural stem cell lines can be achieved.

Effects of Xinfeng Capsule(新风胶囊) on the Expression of Platelet Derived Growth Factor in Synovium of Adjuvant Arthritis Rats

Objective： To observe the effects of Xinfeng Capsule （新风胶囊, XFC） on platelet parameters in peripheral blood and expression of platelet derived growth factor （PDGF） in synovium of adjuvant arthritis （AA） rats. Methods： A total of 40 male Sprague-Dawley （SD） rats were randomized into 5 groups： normal control （NC）, AA model control （MC）, methotrexate （MTX） treatment, Tripterygium wilfordii polycoride tablet （TPT） treatment, and XFC treatment. Excluding the NC group, the AA model was induced by intracutaneous injection of 0.1 mL Freund＇s complete adjuvant in the right hind limb. Induction of AA and the effects of drug treatments were assessed by voix pedis swelling, arthritis index （AL） body mass, and the pathological changes of joints and cartilage with a light microscopy. Platelet parameters in peripheral blood were detected with an automated hematology analyzer. PDGF in synovium was detected with immunohistochemical methods and PDGF mRNA expression in synovium was detected with reverse transcription polymerase chain reaction. Results： Compared with the NC group, the MC group had significantly increased voix pedis swelling, AI, platelet （PLT） and plateletcrit （PCT） in peripheral blood and PDGF as well as PDGF mRNA in synovium （all P〈0.01） and the joint cartilage was also highly degenerated. Compared with the MC group, the 3 treated groups had significantly decreased voix pedis swelling, AI, PLT, PCT, PDGF, and PDGF mRNA （P〈0.01）. The body mass in the XFC group was significantly higher than those in MTX and TPT groups （P〈0.05）. The levels of PLT, PCT, PDGF, and PDGF mRNA in the XFC group showed a decreasing tendency with no significant difference compared with the M＇IX and TPT groups （P〉0,05）. PDGF and PDGF mRNA of AA rats were positively correlated with voix pedis swelling, AI, PLT, and PCT （P〈0.05 or P〈0.01）. Conclusions： The expression and biosynthesis of PDGF increase in the synovium of AA rats and correlate with voix pedis swelling, AI, PLT, and PCT. XFC can decrease the levels of PDGF, PDGF mRNA, PLT, and PCT, thereby mitigating inflammation induced by platelet activation and reducing voix pedis swelling and the AI in AA rats.

Platelet derived growth factor and basic fibroblast growth factor immunolocalized in proliferative retinal diseases

Objective To study the role of platelet derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) in the development of proliferative vitreoretinopathy (PVR) Methods Immunohistochemical localization was performed on frozen sections of the epiretinal or subretinal membranes from 21 PVR patients using!monoclonal antibodies against PDGF and bFGF and the streptavidin peroxidase system Results PDGF was expressed in 15 of 21 specimens (71 4%), and bFGF was expressed in 14 specimens (66 7%) Different cell density was seen in different types of epiretinal membranes The cell density of vascular membranes induced by PDR and Eales disease was the highest (≥61 cells/field, ×1000); nonvascular membranes induced by PVR or traumatic PVR had moderate cell density (31-60 cells/field); and the macular membrane had the lowest cell density (≤30 cells/field) Conclusion The presents of PDGF and bFGF in PVR tissues suggest that PDGF and bFGF may play an important role in the development of PVR

Cloning, expression and functional analyses of human platelet-derived growth factor-B chain peptide for wound repair of cat corneal endothelial cells

Objective: To investigate the biological function of platelet-derived growth factor B (PDGF-B) on the survival and proliferation of cat corneal endothelial cells so as to provide bases for further studies of its role in wound repair and its clinical application.Methods: Total RNA was extracted from the placenta tissues of healthy pregnant women undergoing hysterotokotomy and PDGF eDNA was obtained with re-verse transcription-polymerase chain reaction (RT-PCR). The prokaryotic expression vector pET-PDGF-B was constructed and expressed the recombinant PDGF-B in Escherichia coli (E.coli) BL21 (DE3). After purification and refolding on Ni2+-chelation affinity chromatography (NTA) column, it was used to culture cat corneal endothelial cells. Cell proliferation was tested by modified tertrazolium salt (MTT) and flow cytometer. And the morphologic change and the ultrastructure were ob-served under an inverted phase contrast microscope, a scan-ning electron microscope and a transmission electon microscope, respectively.Results: PDGF-B chain peptide (PDGF-BB) gene was successfully inserted into the prokaryotic expression vector, pET-28a(+). The purified recombined protein pET-PDGF-B showed a single band on sodium dodecyl sulfate polyacry-lamide gel electropheresis (SDS-PAGE) with the molecular weight of about 27 u, which was in agreement with the de-duced value. MTT and flow cytometry showed that PDGF-BB promoted the survival and proliferation of cat corneal en-dothelial cells.Conclusions: The construction of recombinant prokary-otic expression vector pET-PDGF-B and the preparation of PDGF-BB protein provide a foundation for further study of the function of PDGF-BB and producing biological PDGF-BB protein. The expressed PDGF-BB promotes the prolif-eration of cultured cat corneal endothelial cells.

Effects of Serum of Kawasaki Disease on PDGF Expression in Monocytes and on Endothelial Cell Apoptosis

The effects of serum of patients with Kawasaki disease on the platelet derived growth factor B (PDGF B) chain protein expression in monocytes were studied by immunocytochemical method and the effects of the serum on the endothelial cellular (EC) apoptosis were observed by flow cytometric technique. It was found that the serum of patients with Kawasaki disease induced significantly the expression of PDGF B chain protein. Likewise, EC apoptosis was increased significantly in the experimental group as compared with the control group ( P < 0.01). The results suggest that PDGF in monocytes increase and EC apoptosis play an important role in the development of coronary artery complication in Kawasaki disease.