Platelet-derived Growth Factor mRNA Research Articles

Effect of macrophage-derived exosomes on promoting hepatic stellate cell activation and platelet-derived growth factor expression

Objective: To explore the effect of macrophage-derived exosomes on the activation of hepatic stellate cells and its possible mechanism. Methods: Differential ultracentrifugation was used to extract macrophage exosomes. The exosomes were co-cultured with the mouse hepatic stellate cell line JS1, and a control group was established with phosphate buffered saline (PBS). Cell immunofluorescence was used to observe the expressional conditions of F-actin. Cell counting kit-8 (CCK8) was used to detect the survival rate of JS1 cells in the two groups. The activation indices of JS1 cells [collagen type Ⅰ (Col Ⅰ) and α-smooth muscle actin (α-SMA)] and its key signal pathway activation index expression level [transforming growth factor (TGF)-β1/Smads, platelet-derived growth factor (PDGF)] in the two groups were determined using Western blot and RT-PCR. Data comparison between two groups was performed using an independent sample t-test. Results: The membrane structure of exosomes was clearly observed by transmission electron microscopy. The expression of exosome marker proteins CD63 and CD81 was positive, suggesting that exosomes were successfully extracted. Exosomes were co-cultured with JS1 cells. Compared with the PBS control group, there was no statistically significant difference in the proliferation rate of JS1 cells in the exosomes group (P＞0.05). The expression of F-actin was significantly increased in the exosome group. The mRNA and protein expression levels of α-SMA and ColⅠwere significantly increased in exosome group JS1 cells (all P＜0.05). The mRNA relative expression levels of α-SMA in PBS and exosome group were 0.25±0.07 and 1.43±0.19, respectively, while that of ColⅠ was 1.03±0.04 and 1.57±0.06, respectively. The mRNA and protein expressions of PDGF were significantly increased in exosome group JS1 cells (P＜0.05). The mRNA relative expression levels of PDGF in the PBS group and exosome group were 0.27±0.04 and 1.65±0.12, respectively. There were no statistically significant differences in the mRNA and protein expressions of TGF-β1, Smad2 and Smad3 between the two groups (P＞0.05). Conclusion: Macrophage-derived exosomes significantly promote the activation of hepatic stellate cells. JS1 cells may be the underlying mechanism for the up-regulation of PDGF expression.

Bioinformatics Analysis of Exercise-Related Biomarkers in Diabetes.

Background Exercise is a regular behavioral activity that not only helps to lose weight but also reduces the risk of cardiovascular and cerebrovascular diseases. Diabetes is a common disease that plagues human health. It is shown that regular exercise can improve the insulin sensitivity of diabetic patients and have an important function in adjuvant therapy. Methods We downloaded the GSE101931 dataset from the Gene Expression Omnibus (GEO) database, 10 samples were obtained from the GSE101931 dataset, including 5 before exercise and 5 postexercise samples, and GEO2R was used to screen the differentially expressed genes (DEGs) exhibited by a heat map. Then, the enrichment analysis of DEGs in Gene Ontology (GO) function was analyzed by Metascape, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of DEGs was also analyzed by gene set enrichment analysis (GSEA). Next, the protein-protein interaction (PPI) network maps were drawn, and the hub genes were identified through Metascape. Finally, the expressions of the hub genes in the dataset were analyzed. Results Totally, 116 upregulated DEGs and 1017 downregulated DEGs were identified from these data. These DEGs were mainly enriched in the platelet-derived growth factor receptor signaling pathway and mRNA processing. Then, the GSEA analysis showed that 6 KEGG pathways were associated with postexercise prediabetic samples, namely, ABC transporters, focal adhesion, MAPK signaling pathway, prion diseases, melanogenesis, and gap junction. Afterward, three hub genes (HSPA8, STIP1, and HSPH1) were highly expressed after exercise through the box plot analysis. Conclusion A myriad of research results confirms that there is a certain connection between exercise and diabetes, which provides a favorable basis for emerging exercise into the treatment of diabetic patients.

Influence of Silica Exposure for Lung Silicosis Rat.

Objective To investigate the influence of silica exposure on the expression of connective tissue growth factor (CTGF), transforming growth factor beta-1 (TGF-β1), and platelet-derived growth factor (PDGF) in lung silicosis rat. Methods Wistar rats were divided into an experimental group and a control group. In the experimental group, rats were exposed to silica by intratracheal instillation. In the control group, rats were exposed to physiological saline by intratracheal instillation. After 45 days, we compared the level of fibrosis and CTGF, TGF-β1, and PDGF in the lungs by immunohistochemistry or reverse transcription-polymerase chain reaction between the two groups. Results The results showed that the expression levels of CTGF, TGF-β1, and PDGF mRNA were significantly higher in the experimental group than those in the control group (P < 0.05). The positive staining of CTGF, TGF-β1, and PDGF mRNA was found in the cytoplasm, especially in the silicotic nodules of the hyalinisation section and cell endochylema of the alveolar macrophages, type II pneumonocytes, and lung tracheal epithelium. There were significantly positive correlations between CTGF, TGF-β1, and PDGF expressions (P < 0.05). A protein–protein interaction analysis showed interactions between TGF-β1, CTGF, and PDGF. Conclusions TGF-β/CTGF signaling pathway plays an important role in silicosis. Silicon dioxide exposure can induce the expression of CTGF, TGF-β1, and PDGF.

Crosstalk between Cancer Cells and Fibroblasts for the Production of Monocyte Chemoattractant Protein-1 in the Murine 4T1 Breast Cancer.

The chemokine monocyte chemoattractant protein-1 (MCP-1/CCL2) is shown to promote the progression of breast cancer. We previously identified cancer cell-derived granulocyte-macrophage colony-stimulating factor (GM-CSF) as a potential regulator of MCP-1 production in the murine 4T1 breast cancer, but it played a minimum role in overall MCP-1 production. Here, we evaluated the crosstalk between 4T1 cells and fibroblasts. When fibroblasts were co-cultured with 4T1 cells or stimulated with the culture supernatants of 4T1 cells (4T1-sup), MCP-1 production by fibroblasts markedly increased. 4T1 cells expressed mRNA for platelet-derived growth factor (PDGF)-a, b and c, and the PDGF receptor inhibitor crenolanib almost completely inhibited 4T1-sup-induced MCP-1 production by fibroblasts. However, PDGF receptor antagonists failed to reduce MCP-1 production in tumor-bearing mice. Histologically, 4T1 tumors contained a small number of αSMA-positive fibroblasts, and Mcp-1 mRNA was mainly associated with macrophages, especially those surrounding necrotic lesions on day 14, by in situ hybridization. Thus, although cancer cells have the capacity to crosstalk with fibroblasts via PDGFs, this crosstalk does not play a major role in MCP-1 production or cancer progression in this model. Unraveling complex crosstalk between cancer cells and stromal cells will help us identify new targets to help treat breast cancer patients.

Expression levels of circulatory mir-185-5p, vascular endothelial growth factor, and platelet-derived growth factor target genes in endometriosis.

BackgroundUsing blood-based biomarkers such as microRNAs (miRNAs) may allow particularly effective and minimally invasive diagnosis and treatment of endometriosis. Objective: We evaluated the differential expression of circulating miRNA-185-5p (miR-185-5p), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF) target genes between endometriosis and healthy women.Materials and Methods 25 women with a history of endometriosis (grad III-IV) diagnosed by laparoscopy as the case group and 25 women without endometriosis underwent laparoscopy for ovarian cysts or pelvic pain as the control group were enrolled in this case-control study. Blood samples were obtained, and total RNA was used for high-throughput small RNA sequencing, and this was confirmed by means of quantitative real-time polymerase chain reaction (qRT-PCR).ResultsmiRNA expression profiling using non-coding RNA sequencing revealed that one miRNA including miR-185-5p was significantly down-regulated in the case group compared with the controls. The qRT-PCR results showed significant downregulation of the expression level of miR-185-5p (p 0.01) in the plasma of the case group. Receiver operating characteristic (ROC) curve analysis showed the area of miR-185-5p under the ROC curve for endometriosis diagnosis was 0.919 (p 0.001). The RT-PCR results demonstrated that there was no significant difference in the expression of VEGF and PDGF mRNA of blood samples in the cases compared to the control group (PDGF, p = 0.09 and VEGF, p = 0.36).ConclusionThe low expression of miR-185-5p in the plasma of women with endometriosis could be employed as an important non-invasive biomarker for early detection and screening of endometriosis by blood samples.

Overexpression of Platelet-Derived Growth Factor and Its Receptor Are Correlated with Oral Tumorigenesis and Poor Prognosis in Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is a cancerous disease with poor prognosis. According to the statistics, the 5-year survival rate has not improved significantly over the past 20 years. The platelet-derived growth factor (PDGF) and its signaling pathway is a key regulator of angiogenesis and tumorigenesis. High level of PDGF and its receptor (PDGFR) have been reported in several types of malignancies. In this study, we investigated the relationship of the molecular expression levels of PDGF and PDGFR with clinicopathological parameters in OSCC. To this end, we measured the mRNA and protein levels of PDGF and PDGFR by real-time quantitative PCR (qRT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA), respectively. We found positive correlations of the mRNA levels of PDGFA, PDGFB, and PDGFRB with lymph node metastasis and poor overall survival (OS). High expression of PDGF, PDGFRA, and PDGFRB were remarkably associated with lymph node metastasis and poor OS, as determined by immunohistochemistry. Preoperative serum levels of PDGF-AA and PDGF-BB had a positive correlation with preoperative platelet count. Elevated serum levels of PDGF-AA. PDGF-BB, and platelet count correlated with lymph node metastasis and an unfavorable outcome. In multivariate Cox regression analysis, PDGFA mRNA, PDGFB mRNA, PDGFRB mRNA, PDGF immunoexpression, PDGFRB immunoexpression, serum PDGF-AA, serum PDGF-BB, and platelet count emerged as significant independent prognostic factors for OS. In vitro, we found that elevated PDGF promotes colony formation, migration, and invasiveness of SAS and OECM-1 cancer cell lines. Our results suggest that the expression level of serum PDGF has the potential to become a useful diagnostic marker for the prognosis of OSCC. In addition, PDGFR should be considered as a potential therapeutic target for OSCC. Furthermore, research should be undertaken to elucidate the role of PDGF and PDGFR regarding the behavior of tumor cells in OSCC.

Serum lipid, homocysteine, and platelet derived growth factor in patients with hypertension

Purpose The purpose of this paper is to study serum lipids, lipoproteins, homocysteine (Hcy) and platelet-derived growth factor (PDGF), and to evaluate the relationship between serum lipids, lipoproteins, Hcy and PDGF in patients with hypertension. Design/methodology/approach In total, 85 patients with hypertension (34 males, 51 females) were recruited from October to December 2015 at Saraphi Hospital, Chiang Mai Province using purposive sampling. PDGF mRNA levels of the patients were analyzed using the RT-PCR method. Hcy was analyzed by high-performance liquid chromatography. An enzymatic-colorimetric method was used to measure serum cholesterol, high-density lipoprotein cholesterol and triglyceride. A low-density lipoprotein cholesterol (LDL-C) level was calculated using Friedewald’s formula. Descriptive statistics and the Pearson product moment were also used in the analysis. Findings Among the patients with hypertension, hypercholesterolemia, high levels of LDL-C, hypertriglyceridemia and hyperhomocysteinemia were found in 54.1, 70.7, 25.9 and 44.7 percent, respectively. In addition, PDGF was significantly correlated with Hcy (r=0.705; p&lt;0.005). There was no association between serum lipids or lipoproteins and Hcy or PDGF in patients with hypertension. Practical implications The results of this study provide direction on how serum lipids, lipoproteins, Hcy and PDGF can be used as a guide to improving dietary management as a means of reducing cardiovascular disease, and stroke in patients with hypertension. Originality/value This manuscript is not currently under consideration, in press or published elsewhere. This manuscript is truthful original work without fabrication, fraud or plagiarism. The authors have made important scientific contributions to this study. The authors are familiar with the primary data, and have read the entire manuscript and take responsibility for it content. No benefits were received by the authors or any member of the authors’ family or the research team, from any commercial source, directly or indirectly related to this work. Moreover, no one affiliated with has any financial interest related to the subject matter of this manuscript.

Profibrotic epithelial phenotype: a central role for MRTF and TAZ

Epithelial injury is a key initiator of fibrosis but - in contrast to the previous paradigm - the epithelium in situ does not undergo wide-spread epithelial-mesenchymal/myofibroblast transition (EMT/EMyT). Instead, it assumes a Profibrotic Epithelial Phenotype (PEP) characterized by fibrogenic cytokine production. The transcriptional mechanisms underlying PEP are undefined. As we have shown that two RhoA/cytoskeleton-regulated transcriptional coactivators, Myocardin-related transcription factor (MRTF) and TAZ, are indispensable for EMyT, we asked if they might mediate PEP as well. Here we show that mechanical stress (cyclic stretch) increased the expression of transforming growth factor-β1 (TGFβ1), connective tissue growth factor (CTGF), platelet-derived growth factor and Indian Hedgehog mRNA in LLC-PK1 tubular cells. These responses were mitigated by siRNA-mediated silencing or pharmacological inhibition of MRTF (CCG-1423) or TAZ (verteporfin). RhoA inhibition exerted similar effects. Unilateral ureteral obstruction, a murine model of mechanically-triggered kidney fibrosis, induced tubular RhoA activation along with overexpression/nuclear accumulation of MRTF and TAZ, and increased transcription of the above-mentioned cytokines. Laser capture microdissection revealed TAZ, TGFβ1 and CTGF induction specifically in the tubular epithelium. CCG-1423 suppressed total renal and tubular expression of these proteins. Thus, MRTF regulates epithelial TAZ expression, and both MRTF and TAZ are critical mediators of PEP-related epithelial cytokine production.

Relaxin receptor deficiency promotes vascular inflammation and impairs outward remodeling in arteriovenous fistulas.

The pathophysiology of arteriovenous fistula (AVF) maturation failure is not completely understood but impaired outward remodeling (OR) and intimal hyperplasia are thought to be contributors. This adverse vascular response after AVF surgery results from interplay between vascular smooth muscle cells (VSMCs), the extracellular matrix (ECM), and inflammatory cells. Relaxin (RLN) is a hormone that acts on the vasculature via interaction with RLN/insulin-like peptide family receptor 1 (RXFP1), resulting in vasodilatation, ECM remodeling, and decreased inflammation. In the present study, we evaluated the consequences of RXFP1 knockout ( Rxfp1-/-) on AVF maturation in a murine model of AVF failure. Rxfp1-/- mice showed a 22% decrease in vessel size at the venous outflow tract 14 d after AVF surgery. Furthermore, a 43% increase in elastin content was observed in the lesions of Rxfp1-/- mice and coincided with a 41% reduction in elastase activity. In addition, Rxfp1-/- mice displayed a 6-fold increase in CD45+ leukocytes, along with a 2-fold increase in monocyte chemoattractant protein 1 (MCP1) levels, when compared with wild-type mice. In vitro, VSMCs from Rxfp1-/- mice exhibited a synthetic phenotype, as illustrated by augmentation of collagen, fibronectin, TGF-β, and platelet-derived growth factor mRNA. In addition, VSMCs derived from Rxfp1-/- mice showed a 5-fold increase in cell migration. Finally, RXFP1 and RLN expression levels were increased in human AVFs when compared with unoperated cephalic veins. In conclusion, RXFP1 deficiency hampers elastin degradation and results in induced vascular inflammation after AVF surgery. These processes impair OR in murine AVF, suggesting that the RLN axis could be a potential therapeutic target for promoting AVF maturation.-Bezhaeva, T., de Vries, M. R., Geelhoed, W. J., van der Veer, E. P., Versteeg, S., van Alem, C. M. A., Voorzaat, B. M., Eijkelkamp, N., van der Bogt, K. E., Agoulnik, A. I., van Zonneveld, A.-J., Quax, P. H. A., Rotmans, J. I. Relaxin receptor deficiency promotes vascular inflammation and impairs outward remodeling in arteriovenous fistulas.

Influence of amygdalin on PDG, IGF and PDGFR expression in HSC-T6 cells.

The aim of the present study was to elucidate the mechanism of amygdalin treatment on reducing liver fibrosis by investigating its role in regulating the expression level of platelet-derived growth factor (PDGF), insulin-like growth factor (IGF) and PDGF receptor (PDGFR) in the hepatic stellate cell (HSC)-T6 line. HSC-T6 cells were used as an in vitro model and randomly assigned into four groups: control, high-dose amygdalin, mid-dose amygdalin and low-dose amygdalin. Following amygdalin treatment, compared with the control, a high dose of amygdalin significantly suppressed the mRNA expression of PDGF and IGF (each P<0.05), whereas moderate and low doses showed no significant effect, relatively low doses of amygdalin are not sufficient to transfer signals to its receptor. The high-dose amygdalin and low-dose amygdalin displayed suppressed protein expression of PDGF at 24, 48 and 72 h, with the high-dose group exhibiting the most marked suppression at all three time points. By reducing the transcription of PDGF and IGF mRNA and the expression of PDGF protein, amygdalin decreased the synthesis and release of PDGF and IGF, thereby reducing the influence of PDGF and IGF on HSCs, thus protecting the liver from fibrosis.

Bone marrow-derived mesenchymal stem cells induced by inflammatory cytokines produce angiogenetic factors and promote prostate cancer growth

BackgroundProstate is susceptible to infection and pro-inflammatory agents in a man’s whole life. Chronic inflammation might play important roles in the development and progression of prostate cancer. Mesenchymal stem cells (MSCs) are often recruited to the tumor microenvironment due to local inflammation. We have asked whether stimulation of MSCs by pro-inflammatory cytokines could promote prostate tumor growth. The current study investigated the possible involvement of MSCs stimulated by pro-inflammatory cytokines in promotion and angiogenesis of prostate cancer through relative pathway in vitro and in vivo.MethodsA syngeneic mouse model of C57 was established. The murine prostate cancer cells (RM-1) mixing with MSCs treated with tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) or vehicle were subcutaneously injected into C57 mice. Tumor volume of C57 mouse model was estimated and serum level of platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) was test by Enzyme-linked Immunosorbent Assay (ELISA). A hen egg test-chorioallantoic membrane (HET-CAM) assay was applied to test the effect of conditioned media of stimulated MSCs in chorioallantoic membrane angiogenesis. Short interfering RNA (siRNA) knocked down either hypoxia-inducible factor-1alpha (HIF-1α) or nuclear factor-erythroid-2-related factor 2 (NRF2) were employed. mRNA of PDGF and VEGF in MSCs, as well as NRF2 and HIF-1α was test by Real time polymerase chain reaction (PCR) analyses. Protein expression levels of PDGF and VEGF from conditioned medium, NRF2, HIF-1α, as well as PDGF and VEGF in MSCs were detected by Western blot analysis.ResultsMSCs treated with TNF-α and IFN-γ promote tumor growth in C57 syngeneic mouse model, correlating with increased serum level of PDGF, VEGF. HET-CAM assay shows the angiogenic effect of conditioned medium of MSCs pre-treated with the pro-inflammatory cytokines. mRNA and protein levels of two pro-angiogenic factors (PDGF and VEGF) and key hypoxia regulators (HIF-1α and NRF2) in MSCs were induced after MSCs’ pretreatment. siRNA knockdown either HIF-1α or NRF2 results reduction of PDGF and VEGF expression.ConclusionsMSCs stimulated by pro-inflammatory cytokines increase the expression of PDGF and VEGF via the NRF2-HIF-1α pathway and accelerate prostate cancer growth in mice.

Effect of cannabinoid receptor-2 agonist AM1241 on platelet-derived growth factor expression in the liver tissue of mice with hepatic fibrosis

Objective: To investigate the effect of cannabinoid receptor-2 (CB2) agonist AM1241 on the mRNA and protein expression of platelet-derived growth factor (PDGF) and collagen-III (Col-III) in the liver tissue of mice with experimental liver fibrosis induced by carbon tetrachloride (CCl(4)). Methods: Totally 38 8-week-old male C57BL/6J mice were randomly divided into control group, model group, 3 mg/kg CB2 receptor agonist (AM1241) group, and 9 mg/kg AM1241 group. All mice, except for the control group, were treated with 30% CCl(4) (three times a week, 5 ml/kg body weight, 16 weeks) to establish a liver fibrosis model. Meanwhile, 3 and 9 mg/kg AM1421 was intraperitoneally injected for daily intervention, respectively. The dosage was adjusted according to actual body weight. The same solvent was given in the control group. The serum level of aspartate aminotransferase (AST) was measured by serum enzyme digestion. The liver inflammation and fibrosis were observed by HE staining of tissue slices. The mRNA and protein expression of PDGF and Col-III in hepatic tissue was determined by real-time PCR and immunohistochemistry. Results: Compared with the control group, the mice in model group showed severe liver fibrosis, significantly elevated serum AST level (742 ± 300.8 U/L vs 118.1 ± 31.1 U/L, P < 0.05), and significantly increased mRNA and protein expression of PDGF and Col-III in liver tissue (P < 0.05). Compared with the model group, the mice in 3 mg/kg AM1241 group and 9 mg/kg AM1241 group had less severe liver fibrosis, and significantly reduced serum AST levels (116.6 ± 13.68 U/L vs 742 ± 300.8 U/L, P < 0.05; 113.8 ± 16.01 U/L vs 742 ± 300.8 U/L, P < 0.05) and mRNA and protein expression of PDGF and Col-III in liver tissue (P < 0.05). Conclusion: CB2 receptor agonist AM1241 can inhibit the mRNA and protein expression of PDGF in the liver tissue of mice with hepatic fibrosis, and reduce extracellular matrix synthesis.

Combination therapy with human umbilical cord mesenchymal stem cells and angiotensin-converting enzyme 2 is superior for the treatment of acute lung ischemia-reperfusion injury in rats.

Acute lung ischemia-reperfusion injury (ALIRI) is a serious disease that seriously affects human's life. In this study, we aimed to explore a more effective treatment method by combining human umbilical cord mesenchymal stem cells (HUMSCs) and angiotensin-converting enzyme 2 (ACE2) for ALIRI. Fifty rats were firstly divided into five groups, namely sham surgery group (sham) and four model groups (model, ACE2, HUMSCs and HUMSCs + ACE2) that were reperfused with 0.1 ml physiological saline (PS), 0.1 ml PS containing 1 × 10(6) lentiviral-ACE2/HUMSCs/ACE2 + UMSCs, respectively. Quantitative reverse transcription-PCR (qRT-PCR) and western blot assays were then conducted to detect the messenger RNA (mRNA) and protein levels of inflammatory cytokines [intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), tumour necrosis factor α (TNF-α), nuclear factor κB (NF-κB), platelet-derived growth factor (PDGF) and angiotensin II (Ang II)], antioxidant proteins [NAD(P)H quinone oxidoreductase 1 (NQO1), heme oxygenase 1 (HO-1)], DNA damage and apoptotic indicators [BCL2-associated X (Bax), cleaved caspase-3 (C-Csp 3), cleaved-poly(ADP-ribose) polymerase (C-PARP), Y-H2AX], anti-apoptotic indicator (Bcl-2) and smooth muscle cell proliferation indicator [connexin 43 (Cx43)]. According to the qRT-PCR and western results, the mRNA and protein expression levels of ICAM-1, VCAM-1, TNF-α, NF-κB, PDGF, Bax, C-Csp 3, C-PARP and Y-H2AX were significantly higher in model group than those in sham group and they were significantly reduced by HUMSCs or ACE2 treatment (P < 0.05). On the contrary, Bcl-2 showed an opposite expression trend with the previous proteins. The mRNA and protein levels of NQO1 and HO-1 were sequentially increased in sham, model, ACE2, HUMSCs and HUMSCs + ACE2 groups. Besides, HUMSCs combined with ACE2 exhibited a better inhibition effect on ALIRI than HUMSCs or ACE2 alone (P < 0.05). In summary, HUMSCs combined with ACE2 was demonstrated to have the best therapeutic effect on ALIRI through anti-inflammation, oxidative stress and anti-apoptotic processes.

Effects of Xinfeng Capsule on the expression of platelet derived growth factor in synovium of adjuvant arthritis rats.

To observe the effects of Xinfeng Capsule (, XFC) on platelet parameters in peripheral blood and expression of platelet derived growth factor (PDGF) in synovium of adjuvant arthritis (AA) rats. 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 (AI), 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. 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 MTX 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). 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.

Aberrant DNA methylation of the PDGF gene in homocysteine‑mediated VSMC proliferation and its underlying mechanism.

It is well established that homocysteine (Hcy) is an independent risk factor for atherosclerosis (AS), which is characterized by vascular smooth muscle cell (VSMC) proliferation. However, the molecular mechanism underlying AS in VSMCs is yet to be elucidated. The aim of this study was to investigate the potential involvement of aberrant DNA methylation of the platelet‑derived growth factor (PDGF) gene in Hcy‑mediated VSMC proliferation and its underlying mechanism. Cultured human VSMCs were treated with varying concentrations of Hcy. VSMC proliferation, PDGF mRNA and protein expression and PDGF promoter demethylation showed a dose‑dependent increase with Hcy concentration, suggesting an association among them. Cell cycle analysis revealed a decreased proportion of VSMCs in G0/G1 and an increased proportion in Sphase, indicating that VSMC proliferation was increased under Hcy treatment. Furthermore, S‑adenosylhomocysteine (SAH) levels were observed to increase and those of S‑adenosylmethionine (SAM) were observed to decrease. The consequent decrease in the ratio of SAM/SAH may partially explain the hypomethylation of PDGF with Hcy treatment. Folate treatment exhibited an antagonistic effect against Hcy‑induced VSMC proliferation, aberrant PDGF methylation and PDGF expression. These data suggest that Hcy may stimulate VSMC proliferation through the PDGF signaling pathway by affecting the epigenetic regulation of PDGF through the demethylation of its promoter region. These findings may provide novel insight into the molecular association between aberrant PDGF gene demethylation and the proliferation of VSMCs in Hcy‑associated AS.

Platelet-derived Growth Factor-C (PDGF-C) Induces Anti-apoptotic Effects on Macrophages through Akt and Bad Phosphorylation

PDGF-C, which is abundant in the malignant breast tumor microenvironment, plays an important role in cell growth and survival. Because tumor-associated macrophages (TAMs) contribute to cancer malignancy, macrophage survival mechanisms are an attractive area of research into controlling tumor progression. In this study, we investigated PDGF-C-mediated signaling pathways involved in anti-apoptotic effects in macrophages. We found that the human malignant breast cancer cell line MDA-MB-231 produced high quantities of PDGF-C, whereas benign MCF-7 cells did not. Recombinant PDGF-C induced PDGF receptor α chain phosphorylation, followed by Akt and Bad phosphorylation in THP-1-derived macrophages. MDA-MB-231 culture supernatants also activated macrophage PDGF-Rα. PDGF-C prevented staurosporine-induced macrophage apoptosis by inhibiting the activation of caspase-3, -7, -8, and -9 and cleavage of poly(ADP-ribose) polymerase. Finally, TAMs isolated from the PDGF-C knockdown murine breast cancer cell line 4T1 and PDGF-C knockdown MDA-MB-231-derived tumor mass showed higher rates of apoptosis than the respective WT controls. Collectively, our results suggest that tumor cell-derived PDGF-C enhances TAM survival, promoting tumor malignancy.

The PDGFRβ–AKT Pathway Contributes to CDDP-Acquired Resistance in Testicular Germ Cell Tumors

We examined whether PI3K-AKT or extracellular signal-regulated kinase (ERK) signaling pathways could play a role in the development of cisplatin (CDDP) resistance in testicular germ cell tumor (TGT) cells. We compared AKT and ERK activation levels in CDDP-sensitive testicular tumor cells and in their corresponding CDDP-resistant-derived cells. We also analyzed these pathways in orthotopic testicular tumors and human patient samples. Our results indicated that there was overactivation of AKT in CDDP-resistant cells compared with sensitive cells, but no effect on activated ERK levels. We observed an increase in mRNA and protein levels for platelet-derived growth factor (PDGF) receptor β and PDGF-B ligand. These were responsible for AKT overactivation in CDDP-resistant cells. When PDGFRβ levels were decreased by short hairpin RNA (shRNA) treatment or its activation was blocked by pazopanib, CDDP-resistant cells behaved like sensitive cells. Moreover, CDDP-resistant cells were more sensitive to incubation with PDGFRβ inhibitors such as pazopanib or sunitinib than sensitive cells, a finding consistent with these cells being dependent on this signaling pathway. We also found overexpression of PDGFRβ and pAKT in CDDP-resistant choriocarcinoma orthotopic tumor versus their CDDP-sensitive counterparts. Finally, we found high PDGFRβ levels in human testicular tumors, and overexpression in CDDP-resistant testicular choriocarcinomas compared with the CDDP-sensitive and nontreated tumors. The PDGFRβ-AKT pathway plays a critical role in the development of CDDP resistance in testicular tumoral cells.

Iloprost Up-regulates Vascular Endothelial Growth Factor Expression in Human Dental Pulp Cells In Vitro and Enhances Pulpal Blood Flow In Vivo

IntroductionProstacyclin (PGI2) is a biomolecule capable of enhancing angiogenesis and cellular proliferation. MethodsWe investigated the influence of a PGI2 analogue (iloprost) on dental pulp revascularization in vitro and in vivo by using human dental pulp cells (HDPCs) and a rat tooth injury model, respectively. Iloprost stimulated the human dental pulp cell mRNA expression of vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), and platelet-derived growth factor (PDGF) in a significant dose-dependent manner. This mRNA up-regulation was significantly inhibited by pretreatment with a PGI2 receptor antagonist and forskolin (a protein kinase A activator). In contrast, a protein kinase A inhibitor significantly enhanced the iloprost-induced mRNA expression of VEGF, FGF-2, and PDGF. Pretreatment with a fibroblast growth factor receptor inhibitor attenuated the VEGF, FGF-2, and PDGF mRNA expression, indicating opposing regulatory mechanisms. ResultsThe effect of iloprost on the dental pulp was investigated in vivo by using a rat molar pulp injury model. The iloprost-treated group exhibited a significant increase in pulpal blood flow at 72 hours compared with control. ConclusionsThe present study indicates that iloprost may be a candidate agent to promote neovascularization in dental pulp tissue, suggesting the potential clinical use of iloprost in vital pulp therapy.

PKCδ Impaired Vessel Formation and Angiogenic Factor Expression in Diabetic Ischemic Limbs

Decreased collateral vessel formation in diabetic peripheral limbs is characterized by abnormalities of the angiogenic response to ischemia. Hyperglycemia is known to activate protein kinase C (PKC), affecting the expression and activity of growth factors such as vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). The current study investigates the role of PKCδ in diabetes-induced poor collateral vessel formation and inhibition of angiogenic factors expression and actions. Ischemic adductor muscles of diabetic Prkcd+/+ mice exhibited reduced blood reperfusion, vascular density, and number of small vessels compared with nondiabetic Prkcd+/+ mice. By contrast, diabetic Prkcd−/− mice showed significant increased blood flow, capillary density, and number of capillaries. Although expression of various PKC isoforms was unchanged, activation of PKCδ was increased in diabetic Prkcd+/+ mice. VEGF and PDGF mRNA and protein expression were decreased in the muscles of diabetic Prkcd+/+ mice and were normalized in diabetic Prkcd−/− mice. Furthermore, phosphorylation of VEGF receptor 2 (VEGFR2) and PDGF receptor-β (PDGFR-β) were blunted in diabetic Prkcd+/+ mice but elevated in diabetic Prkcd−/− mice. The inhibition of VEGFR2 and PDGFR-β activity was associated with increased SHP-1 expression. In conclusion, our data have uncovered the mechanisms by which PKCδ activation induced poor collateral vessel formation, offering potential novel targets to regulate angiogenesis therapeutically in diabetic patients.

Cytomegalovirus Infection Accelerates the Process of Chronic Rejection in Rat Liver Transplantation

ObjectiveAnalysis of the pathogenesis of cytomegalovirus (CMV) infection for rat chronic liver rejection. MethodsBased on animal models that we previously developed, we divided control and a CMV infection group to analyze survival, histopathology and rejection activity. The level and mRNA expression of transforming growth factor-β1, platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF) were measured in peripheral blood serum and liver tissue. ResultsObliterative arteriopathy and fibrosis was significantly greater in the CMV infection versus the control group (P < .05). PDGF mRNA expression in rat liver and in peripheral blood were significantly higher in the CMV infection versus the control group (P < .05). bFGF mRNA expression in the CMV infection group was also significantly higher than among the controls (P < .05). ConclusionsCMV infection aggravated foam cell obliterative arteriopathy and liver fibrosis in chronic liver rejection, processes that accelerate the immune response, which may correlate with early high PDGF and bFGF expression.