Fengming Luo

High glucose upregulates connective tissue growth factor expression in human vascular smooth muscle cells

BackgroundConnective tissue growth factor (CTGF) is a potent profibrotic factor, which is implicated in fibroblast proliferation, angiogenesis and extracellular matrix (ECM) synthesis. It is a downstream mediator of some of the effects of transforming growth factor β (TGFβ) and is potentially induced by hyperglycemia in human renal mesangial cells. However, whether high glucose could induce the CTGF expression in vascular smooth muscle cells (VSMCs) remains unknown. Therefore, this study was designed to test whether high glucose could regulate CTGF expression in human VSMC. The effect of modulating CTGF expression on VSMC proliferation and migration was further investigated.ResultsExpression of CTGF mRNA was up-regulated as early as 6 hours in cultured human VSMCs after exposed to high glucose condition, followed by ECM components (collagen type I and fibronectin) accumulation. The upregulation of CTGF mRNA appears to be TGFβ-dependent since anti-TGFβ antibody blocks the effect of high glucose on CTGF gene expression. A small interference RNA (siRNA) targeting CTGF mRNA (CTGF-siRNA) effectively suppressed CTGF up-regulation stimulated by high glucose up to 79% inhibition. As a consequence of decreased expression of CTGF gene, the deposition of ECM proteins in the VSMC was also declined. Moreover, CTGF-siRNA expressing vector partially inhibited the high glucose-induced VSMC proliferation and migration.ConclusionOur data suggest that in the development of macrovascular complications in diabetes, CTGF might be an important factor involved in the patho-physiological responses to high glucose in human VSMCs. In addition, the modulatory effects of CTGF-siRNA during this process suggest that specific targeting CTGF by RNA interference could be useful in preventing intimal hyperplasia in diabetic macrovascular complications.

Angiotensin II upregulates the expression of placental growth factor in human vascular endothelial cells and smooth muscle cells

BackgroundAtherosclerosis is now recognized as a chronic inflammatory disease. Angiotensin II (Ang II) is a critical factor in inflammatory responses, which promotes the pathogenesis of atherosclerosis. Placental growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family cytokines and is associated with inflammatory progress of atherosclerosis. However, the potential link between PlGF and Ang II has not been investigated. In the current study, whether Ang II could regulate PlGF expression, and the effect of PlGF on cell proliferation, was investigated in human vascular endothelial cells (VECs) and smooth muscle cells (VSMCs).ResultsIn growth-arrested human VECs and VSMCs, Ang II induced PlGF mRNA expression after 4 hour treatment, and peaked at 24 hours. 10-6 mol/L Ang II increased PlGF protein production after 8 hour treatment, and peaked at 24 hours. Stimulation with Ang II also induced mRNA expression of VEGF receptor-1 and -2(VEGFR-1 and -2) in these cells. The Ang II type I receptor (AT1R) antagonist blocked Ang II-induced PlGF gene expression and protein production. Several intracellular signals elicited by Ang II were involved in PlGF synthesis, including activation of protein kinase C, extracellular signal-regulated kinase 1/2 (ERK1/2) and PI3-kinase. A neutralizing antibody against PlGF partially inhibited the Ang II-induced proliferation of VECs and VSMCs. However, this antibody showed little effect on the basal proliferation in these cells, whereas blocking antibody of VEGF could suppress both basal and Ang II-induced proliferation in VECs and VSMCs.ConclusionOur results showed for the first time that Ang II could induce the gene expression and protein production of PlGF in VECs and VSMCs, which might play an important role in the pathogenesis of vascular inflammation and atherosclerosis.

Hypoxia stimulates the expression of macrophage migration inhibitory factor in human vascular smooth muscle cells via HIF-1α dependent pathway

BackgroundHypoxia plays an important role in vascular remodeling and directly affects vascular smooth muscle cells (VSMC) functions. Macrophage migration inhibitory factor (MIF) is a well known proinflammatory factor, and recent evidence suggests an important role of MIF in the progression of atherosclerosis and restenosis. However, the potential link between hypoxia and MIF in VSMC has not been investigated. The current study was designed to test whether hypoxia could regulate MIF expression in human VSMC. The effect of modulating MIF expression on hypoxia-induced VSMC proliferation and migration was also investigated at the same time.ResultsExpression of MIF mRNA and protein was up-regulated as early as 2 hours in cultured human VSMCs after exposed to moderate hypoxia condition (3% O2). The up-regulation of MIF expression appears to be dependent on hypoxia-inducible transcription factor-1α(HIF-1α) since knockdown of HIF-1α inhibits the hypoxia induction of MIF gene and protein expression. The hypoxia induced expression of MIF was attenuated by antioxidant treatment as well as by inhibition of extracellular signal-regulated kinase (ERK). Under moderate hypoxia conditions (3% O2), both cell proliferation and cell migration were increased in VSMC cells. Blocking the MIF by specific small interference RNA to MIF (MIF-shRNA) resulted in the suppression of proliferation and migration of VSMCs.ConclusionOur results demonstrated that in VSMCs, hypoxia increased MIF gene expression and protein production. The hypoxia-induced HIF-1α activation, reactive oxygen species (ROS) generation and ERK activation might be involved in this response. Both MIF and HIF-1α mediated the hypoxia response of vascular smooth muscle cells, including cell migration and proliferation.

Circulating visfatin in chronic obstructive pulmonary disease

OBJECTIVE Malnutrition and continuous systemic inflammation occur frequently in patients with chronic obstructive pulmonary disease (COPD). Visfatin is a new adipokine, which increases in some inflammatory diseases. Its plasma level and relation with nutritional status and inflammation in COPD remain unknown. This study compared visfatin levels, nutritional status, and inflammation markers in patients with COPD and healthy controls. METHODS Plasma visfatin, tumor necrosis factor-alpha (TNF-alpha) and C-reactive protein (CRP) were measured in 35 patients with COPD and 28 healthy controls. Body composition was assessed with bioelectrical impedance analysis. RESULTS Significantly lower body mass index and percentage of body fat were observed in patients with COPD compared with control subjects. The levels of plasma visfatin were higher in the COPD group compared with healthy controls (2.07 +/- 0.18 versus 1.88 +/- 0.15 ng/mL, P < 0.001). Levels of TNF-alpha and CRP were also significantly higher in patients with COPD compared with controls. Plasma CRP and TNF-alpha were positively correlated with visfatin in the COPD group. No significant correlations were found between visfatin and body mass index or percentage of body fat in both groups. CONCLUSION Plasma visfatin levels increased in patients with COPD. This increased adipocytokine was significantly correlated with TNF-alpha and CRP. Visfatin may be a new proinflammatory adipocytokine in this disease.

Homocysteine induces connective tissue growth factor expression in vascular smooth muscle cells

Summary.  Background: Increased homocysteine levels in blood might be an important risk factor for the development of cardiovascular diseases. Connective tissue growth factor (CTGF) was found to be involved in atherosclerotic plaque progression. So far, the possible connection between homocysteine and CTGF has not been studied.

Increased Plasma miRNA-30a as a Biomarker for Non-Small Cell Lung Cancer

Background MicroRNA (miRNA) is a small, non-coding RNA molecule which plays a role in the carcinogenesis and progression of cancers. Abnormal expression of miRNA in plasma has been found in some patients with malignant tumors. Material/Methods This study was conducted to investigate the expression of miRNA-30a in plasma of patients with non-small cell lung cancer (NSCLC). The plasma miRNA-30a in 87 patients with NSCLC, 20 patients with benign lung diseases, and 76 healthy subjects were measured by real-time PCR. The diagnostic value of miRNA-30a in NSCLC was evaluated via the ROC curve method. Results Plasma miRNA-30a level was significantly higher in the NSCLC group compared with benign control and healthy control groups (P<0.01). No statistically significant difference was found in the expression level of miRNA-30a among various clinical pathologic features in NSCLC. ROC curve analysis showed that the specificity and sensitivity cut-off points were at 61.0% and 84.3% for NSCLC. The specificity and sensitivity values were 54.9% and 94.4%, respectively, in the analysis based on in-patients only. Conclusions All these results suggest that plasma miRNA-30a measurement may be a novel and noninvasive method for NSCLC preliminary screening and differential diagnosis.

Forkhead box protein A2 and T helper type 2-mediated pulmonary inflammation

The transcription factor forkhead box protein A2 (FOXA2, also known as hepatocyte nuclear factor 3β or transcription factor 3β), has been found to play pivotal roles in multiple phases of mammalian life, from the early development to the organofaction, and subsequently in homeostasis and metabolism in the adult. In the embryonic development period, FOXA2 is require d for the formation of the primitive node and notochord, and its absence results in embryonic lethality. Moreover, FOXA2 plays an important role not only in lung development, but also in T helper type 2 (Th2)-mediated pulmonary inflammation and goblet cell hyperplasia. In this article, the role of FOXA2 in lung development and Th2-mediated pulmonary inflammation, as well as in goblet cell hyperplasia, is reviewed. FOXA2 deletion in airway epithelium results into Th2-mediated pulmonary inflammation and goblet cell hyperplasia in developing lung. Leukotriene pathway and signal transducers and activators of transcription 6 pathway may mediate this inflammation through recruitment and activation of denditric cell during lung developments. FOXA2 is a potential treatment target for lung diseases with Th2 inflammation and goblet cell hyperplasia, such as asthma and chronic obstructive pulmonary disease.