Decreased serum platelet derived growth factor BB levels in acute and increased in chronic pancreatitis

AIM: To examine circulating growth factor concentrations in patients with acute pancreatitis (AP) and chronic pancreatitis (CP), and walled-off pancreatic necrosis (WOPN).

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.

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.

Primary multiple extragastrointestinal stromal tumors of the omentum with different mutations of c-kit gene

The author reports a very rare case of sporadic primary multiple extragastrointestinal stromal tumors (EGISTs) of the omentum associated with different mutations of the exon 11 of the c-kit gene in a 75-year-old man with gastric cancer. During an operation for the cancer, two solid tumors (10 mm and 8 mm) were found in the omentum. Both tumors consisted of cellular spindle cells. Mitotic figures were two and three per 50 high power fields. The tumor cells were positive for KIT, CD34 and vimentin, but negative for desmin, S100 protein, α-smooth muscle actin and p53 protein. Ki67 labeling was 2% and 3%. The larger EGIST showed a deletion of codons 552-558 of exon 11 of the c-kit gene, while the smaller EGIST had a point mutation at codon 559 (GTT←GAT) in exon 11 of the c-kit gene. Exons 9, 13, and 17 of the c-kit gene, and exons 12 and 18 of the platelet derived growth factor receptor α genes showed no mutations. The case shows that sporadic multiple EGISTs can occur in the omentum.

KIT exon 11 codon 557/558 deletion/insertion mutations define a subset of gastrointestinal stromal tumors with malignant potential

AIM: To study the association of the frequency and pattern of KIT and PDGFRA mutations and clinicopathological factors in a group of patients with gastrointestinal stromal tumors (GIST). METHODS: Thirty patients with GIST were examined. Exons 9, 11, 13, and 17 of the KIT and exons 12 and 18 of the PDGFRA gene were analyzed for the presence of mutations by PCR amplification and direct sequencing. RESULTS: KIT or PDGFRA mutations were detected in 21 of the 30 patients (70%). Sixteen patients had mutations within KIT exon 11, three within KIT exon 9, and two within PDGFRA exon 18. GISTs with KIT exon 9 mutations were predominantly located in the small intestine, showed a spindle cell phenotype, and were assessed as potentially malignant. GISTs with KIT exon 11 mutations were located in the stomach and intestine, showed mainly a spindle cell phenotype, and were scored as potentially malignant (P < 0.05). Tumors with KIT exon 11 codon 557/558 deletion/insertion mutations were found to be associated with a potentially malignant clinical behaviour (P < 0.003). GISTs with PDGFRA mutations located in stomach showed a mixedcell phenotype and were classified as of very low or low moderate malignant potential. CONCLUSION: Determination of KIT and PDGFRA mutations should be additional parameters for the better prediction of GISTs clinical behaviour. Tumors with deletion/insertion mutations affecting codons 557/558 of the KIT gene seem to represent a distinct subset of malignant GISTs.

Amelanotic malignant melanoma of the esophagus:Report of two cases with immunohistochemical and molecular genetic study of KIT and PDGFRA

The author reports herein two cases of amelanotic malignant melanoma of the esophagus. Case 1 is an 87-year-old woman who was admitted to our hospital because of nausea and vomiting. Endoscopic examination revealed an ulcerated tumor of the distal esophagus, and a biopsy was taken. The biopsy showed malignant polygonal and spindle cells. No melanin pigment was recognized. Immunohistochemically, the tumor cells were positive for melanosome （HMB45）, S100 protein, KIT and Platelet derived growth factor receptor-α （PDG- FRA）. The patient was treated by chemotherapy and radiation, but died of systemic metastasis 12 mo after the presentation. Case 2 is a 56-year-old man presenting with dysphagia. Endoscopic examination revealed a polypoid tumor in the middle esophagus, and a biopsy was obtained. The biopsy showed malignant spindle cells without melanin pigment. Immunohistochemically, the tumor cells were positively labeled for melanosome,S100 protein, KIT and PDGFRA. The patient refused operation, and was treated by palliative chemotherapy and radiation. He died of metastasis 7 mo aEer the admission. In both cases, molecular genetic analyses of gene （exons 9, 11, 13 and 17） and PDGFRA gene （exons 12 and 18） were performed by the PCR direct sequencing method, which showed no mutations of KIT and PDGFRA genes. This is the first report of esophageal malignant melanoma with an examination of the expression of KIT and PDGFRA and the mutational status of K/T and PDGFRA genes.

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.

Effects of Salvia miltiorrhiza injectional powder on the development of liver fibrosis initiated by dimethylnitrosamine in rats

Salvia miltiorrhiza （Sm） is a traditional herbal medicine with multiple effects on various diseases. Its water-soluble parts have been used to produce injectional powder. In this study, liver fibrosis rats were induced by intraperitoneal injection of dimethylnitrosarnine for 3 consecutive days per week for 4 weeks. After 2 weeks, rats in the positive drug group were subcutaneously injected with 8×10^5 IU/kg IFNα2b, while the Sm treatment groups were intraperitoneally injected with 50, 100 and 200 mg/kg solution of Sm injectional powder, respectively, for 6 days per week for 4 weeks. The results showed that either IFNα2b or the Sm injectional powder significantly increased the body weight and liver to spleen ratio, and three doses of the powder brought down the spleen index. Serum analysis showed that both IFNα2b and the Sm powder reduced levels of alanine transaminase and total bilirubin, while only 100 and 200 mg/kg of the Sm powder ameliorated aspartate transaminase and albumin levels. In the collagen examination, reduced hyaluronic acid and procollagen type III levels, less fibrous hyperplasia and collagen deposits, and improved hepatocyte states were clearly observed in rats treated with either IFNα2b or Sm injectional powder. In addition, the mechanism of action of the Sm powder was also studied. Immunohistochemical staining showed that IFNα2b and Sm injectional powder significantly down-regulated the expression of transforming growth factor-β1 （TGF-β1） and platelet derived growth factor （PDGF）. In conclusion, Sm injectional powder has protective effects on dimethylnitrosamine-initiated liver fibrosis in rats, and the mechanism may include the down-regulation of TGF-β1 and PDGF.