Muscle Cell Proliferation Research Articles

Enhanced Rb/E2F and TSC/mTOR Pathways Induce Synergistic Inhibition in PDGF-Induced Proliferation in Vascular Smooth Muscle Cells.

Platelet-derived growth factor (PDGF) plays an essential role in proliferation of vascular smooth muscle cells (VSMCs). The Rb/E2F and TSC/mTOR pathways contribute to the proliferation of VSMCs, but its exact roles in PDGF-induced proliferation are unclear. In this study, we demonstrated the roles of Rb/E2F and TSC/mTOR pathways in PDGF-induced proliferation in VSMCs. We found that PDGF stimulates the activity of E2F and mTOR pathways, and knockdown of either Rb or TSC2 increases PDGF-induced proliferation in VSMCs. More interestingly, we revealed that enhancing both E2F and mTOR activity leads to synergistic inhibition of PDGF-induced proliferation in VSMCs. We further identified that the synergistic inhibition effect is caused by the induced oxidative stress. Summarily, these data suggest the important regulations of Rb/E2F and TSC/mTOR pathways in PDGF-induced proliferation in VSMCs, and also present a promising way to limit deregulated proliferation by PDGF induction in VSMCs.

Effects of T-type calcium channel inhibitors on monocrotaline-induced pulmonary arterial hypertension in rats

Objective To investigate the effects of T-type calcium channel inhibitors (ProTx-1, micromolar Ni2+ and Mibefradil) on Monocrotaline(MCT)-induced pulmonary arterial hypertension (PAH) in rats. Methods Forty male Sprague-Dawley rats were randomly divided into 5 groups: normal control group, MCT group, ProTx-1 group, micromolar Ni2+ group and Mibefradil group (8 cases in each group). The right ventricular systolic pressure (RVSP), the right ventricular hypertrophy index (RVHI), and the index of pulmonary vascular remodeling(MA%) were measured on day 28 after MCT-treatment.Western blot was used to detect the expression of proliferating cell nuclear antigen(PCNA) and Cleaved Caspase-3 in pulmonary artery. Results (1)RVSP and RVHI in MCT group were significantly higher than those in the other 4 groups (F=21.55, P 0.05). (2)MA% in normal control group[(23.43±1.95)%] was lower than that in MCT group[(80.42±4.30)%], ProTx-1 group[(60.35±3.83)%], micromolar Ni2+ group[(62.44±3.81)%] and Mibefradil group[(58.66±4.23)%](F=216.2, P 0.05), however, they were all signi-ficantly lower than that in MCT group.(3)The expression of PCNA in MCT group was higher than that in normal control group, meanwhile, 3 intervention groups were significantly lower than that in MCT group.The expression of Cleaved Caspase-3 in MCT group was higher than that in normal control group, nevertheless, 3 intervention groups showed no significant changes compared with MCT group, respectively. Conclusions T-type calcium channel inhibitors could ameliorate the progression of MCT-PAH in rats, mainly through suppressing the proliferation of pulmonary artery smooth muscle cells. Key words: Pulmonary arterial hypertension; Monocrotaline; Voltage dependent calcium channel; Proliferation; Apoptosis

Effect of active vitamin D3 on VEGF-induced ADAM33 expression and proliferation in human airway smooth muscle cells: implications for asthma treatment

BackgroundAsthma is a chronic respiratory disease characterized by reversible airway obstruction with persistent airway inflammation and airway remodeling, which is associated with increased airway smooth muscle (ASM) mass. Vascular endothelial growth factor (VEGF) has been implicated in inflammatory and airway blood vessel remodeling in asthma. Recent evidence indicates that a deficiency of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) may influence asthma pathogenesis. A disintegrin and metalloproteinase (ADAM)33 has been identified as playing a role in the pathophysiology of asthma. ADAM33, which is expressed in ASM cells, is suggested to play a role in the function of these cells. Recent studies show that 1,25-(OH)2D3 exerts direct inhibitory effects on passively sensitized human ASM cells in vitro, including inhibition of ADAM33 expression and cell proliferation; however, the mechanism has not been fully understood.MethodsIn order to elucidate the precise mechanism underlying the effect of 1,25(OH)2D3 on VEGF-induced ADAM33 expression and ASM cell proliferation, we tested the effects of 1,25(OH)2D3 on cell cycle progression and evaluated the levels of phospho-VEGF receptor 2 (VEGFR2), phospho-extracellular signal-regulated kinase 1/2 (ERK1/2), and phospho-Akt in VEGF-stimulated ASM cells.ResultsWe found that 1,25(OH)2D3 inhibited VEGF-induced ADAM33 expression and ASM cell proliferation, as well as cell cycle arrest. Additionally, VEGF-induced ADAM33 expression and ASM cell proliferation was suppressed via inhibition of ERK1/2 activity, but not that of Akt. Furthermore, 1,25(OH)2D3 treatment inhibited VEGF-induced activation of VEGFR2 as well as that of ERK and Akt in a concentration-dependent manner. 1,25(OH)2D3 also inhibited transforming growth factor (TGF)-β-induced VEGF secretion by ASM cells.ConclusionsCollectively, our findings suggest that 1,25(OH)2D3 inhibits VEGF-induced ASM cell proliferation by suppressing VEGFR2 and ERK1/2 activation and downregulating ADAM33. Further studies of these mechanisms are needed to facilitate the development of treatments for smooth muscle hyperplasia-associated diseases of the airway such as asthma.

Role of licochalcone A in VEGF-induced proliferation of human airway smooth muscle cells: implications for asthma

Asthma is a chronic respiratory disease characterized by reversible airway obstruction with persistent airway inflammation and airway remodeling, which is associated with increased airway smooth muscle (ASM) mass. Licochalcone A is the predominant characteristic chalcone in licorice root. We found that licochalcone A inhibited vascular endothelial growth factor (VEGF)-induced ASM cell proliferation and induced cell cycle arrest. Additionally, VEGF-induced ASM cell proliferation was suppressed via inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) activity, but not that of Akt. Furthermore, licochalcone A treatment inhibited VEGF-induced activation of VEGF receptor 2 (VEGFR2) and ERK and blocked the downregulation of caveolin-1 in a concentration-dependent manner. Collectively, our findings suggested that licochalcone A inhibited VEGF-induced ASM cell proliferation by suppressing VEGFR2 and ERK1/2 activation and downregulating caveolin-1. Further studies of these mechanisms are needed to facilitate the development of treatments for smooth muscle hyperplasia-associated diseases of the airway, such as asthma.

Effects of Macrophage Conditioned-Medium on Murine and Human Muscle Cells: Analysis of Proliferation, Differentiation, and Fusion.

Skeletal muscle is a highly plastic tissue, which is able to regenerate after an injury. Effective and complete regeneration requires interactions between myogenic precursor cells and several cell types such as macrophages . Bone marrow derived macrophages in mouse and monocyte-derived macrophages in human are useful tools to obtain macrophage populations that may be specifically activated/polarized in vitro (e.g., pro-inflammatory, anti-inflammatory, and alternatively activated macrophages ). In vitro , human or murine primary myogenic cells recapitulate the adult myogenesis program through proliferation, myogenic differentiation, and fusion. Macrophages being highly secreting cells, they act on various biological processes including adult myogenesis . Here, we present protocols to analyze in vitro the effect of macrophage-secreted factors on muscle cell proliferation or differentiation in both mouse and human.

Growth arrest of vascular smooth muscle cells in suspension culture using low-acyl gellan gum.

The proliferation of vascular smooth muscle cells (SMCs) causes restenosis in biomaterial vascular grafts. The purposes of this study were to establish a suspension culture system for SMCs by using a novel substrate, low-acyl gellan gum (GG) and to maintain SMCs in a state of growth inhibition. When SMCs were cultured in suspension with GG, their proliferation was inhibited. Their viability was 70% at day 2, which was maintained at more than 50% until day 5. In contrast, the viability of cells cultured in suspension without GG was 5.6% at day 2. By cell cycle analysis, the ratio of SMCs in the S phase when cultured in suspension with GG was lower than when cultured on plastic plates. In SMCs cultured in suspension with GG, the ratio of phosphorylated retinoblastoma (Rb) protein to Rb protein was decreased and p27Kip1 expression was unchanged in comparison with SMCs cultured on plastic plates. In addition, SMCs could be induced to proliferate again by changing the culture condition from suspension with GG to plastic plates. These results suggest that our established culturing method for SMCs is useful to maintain SMCs in a state of growth inhibition with high viability.

46 Sandwich-type ethylcellulose films for controlled release of anti-restenosis drugs

Objectives Restenosis is a response of the vessel wall to balloon-induced injury and is characterized primarily by elastic recoil of the vessel wall and a series of pathological processes including thrombus, inflammation and vascular smooth muscle cell (VSMC) proliferation. To treat restenosis, appropriate drug delivery vehicles are needed which can release therapeutic agents targeting different symptoms into blood vessels in a controlled manner. The main objective of the present study was to prepare sandwich-type ethyl cellulose films with high performance for efficient drug loading and controlled drug release for restenosis treatment. Methods Sandwich-type ethyl cellulose films loaded with probucol for treating coronary artery disease, or aspirin as an antithrombotic drug, were prepared by casting three individual layers in sequence using an ethyl cellulose/toluene solution. On a glass plate, the first ethyl cellulose layer (bottom layer) was cast without drugs, on to which the middle layer containing probucol or aspirin was then cast. After solvent evaporation at room temperature, a third top layer was cast on to the middle layer. The obtained drug-loading films were further dried at room temperature under vacuum. Results The sandwich-type ethyl cellulose films exhibited a drug loading content (DLC) of 12.1 ± 0.9% and a drug loading efficiency (DLE) of 73.5 ± 3.6% for aspirin, and a DLC of 11.0 ± 0.8% and a DLE of 69.3 ± 3.4% for probucol. Under physiological conditions (37°C, pH 7.4), the release half-life of aspirin from the films was 2.7 ± 0.2 hours, while that of probucol was 7.1 ± 0.6 days. The two drugs showed totally different release behaviors, which can be employed in combination to treat restenosis. Conclusion Sandwich-type ethylcellulose films loaded with probucol or aspirin were successfully prepared and showed ability to release the two drugs in different ways: rapid release of aspirin to treat thrombus and inflammation typical of early-stage restenosis, and sustained release of probucol for inhibition of VSMC proliferation frequently seen in the later stage of restenosis. These drug-loaded ethylcellulose films provide new insight into restenosis therapy.

Effects of icariin on proliferation of vascular smooth muscle cell induced by ox-LDL via impacting MAPK signaling pathway

This paper was aimed to study the effects of icariin (ICA) on the proliferation of vascular smooth muscle cell (VSMC) induced by oxidized low density lipoprotein (ox-LDL), and the molecular mechanism of the expression of proliferating cell nuclear antigen (PCNA) and MAPK signaling pathway. In this study, VSMC was induced by ox-LDL (50 mg•L⁻¹),the effect of ICA on the proliferation of VSMC was detected by MTT assay, Western blot and Real-time PCR. The results showed that after stimulation of ox-LDL, the proliferation activity of VSMC was increased, S phase, G₂/M phase cells were increased, G₀/G₁ phase cells were decreased, PCNA protein expression was enhanced; ICA (40, 20, 10 μmol•L⁻¹) could effectively inhibit ox-LDL-induced VSMC proliferation, S phase and G₂/M phase cells were decreased, the percentage of cells in G₀/G₁ phase were increased, PCNA expression was decreased, p38MAPK and ERK1/2 activation were inhibited. These results indicate that ICA can inhibit the proliferation of VSMC by reducing the expression of PCNA and blocking the p38MAPK and ERK1/2 signaling pathway.

GW27-e0944 Blocking TRPC5 channel inhibits atherosclerotic plaque development via reducing proliferation and migration of smooth muscle cells

GW27-e0944 Blocking TRPC5 channel inhibits atherosclerotic plaque development via reducing proliferation and migration of smooth muscle cells

GW27-e1069 Synergistic effect of a tissue kallikrein 1 and tissue inhibitor of matrix metalloproteinase 1 co expression vector on the proliferation of rat vascular smooth muscle cells

Tissue kallikrein 1 (TK1) and tissue inhibitor of matrix metalloproteinase 1 (TIMP1) are important in inhibiting vascular smooth muscle cell (VSMC) proliferation and improving vascular remodeling, respectively. It was hypothesized that a combination of TK1 and TIMP1 genes, mediated by an adenovirus

Abstract P292: ENPP1-Fc Protein Inhibits Proliferation of Human Vascular Smooth Muscle Cells

Background: Arterial stenosis leading to hypertension or heart failure is common in patients with Generalized Arterial Calcification of Infancy (GACI), an ultra-rare disease associated with loss of function mutations in ENPP1, an ectonucleotide pyrophosphatase that hydrolyzes extracellular ATP. GACI is characterized by accelerated calcification and severe myointimal proliferation. The role of ENPP1 in myoinitimal proliferation is unknown. Here, we examined the effect of ENPP1 on proliferation of human vascular smooth muscle cells (hVSMCs). Methods: ENPP1 expression was assessed in primary hVSMCs using qRT-PCR. ENPP1 expression was silenced using siRNA and its activity was verified by a cell based assay or inorganic pyrophosphate (PPi) assay and its effect on VSMC proliferation was determined by 3H-thymidine incorporation. Results: Treatment of primary hVSMCs with siRNA specific to the hENPP1 resulted in ~90% decrease in ENPP1 levels. Cellular enzyme activity correlated with ENPP1 expression in VSMCs. Silencing ENPP1 in hVSMCs led to 1-3 fold increase in proliferation relative to that of cells transfected with control siRNA in 2 out of 2 donors. Peak cell proliferation was observed at 5 days post-transfection. Human iPSC derived VSMCs (iVSMCs) expressed higher levels of ENPP1 than primary hVSMCs. Silencing ENPP1 in iVSMCs resulted in 3-5 fold increase in proliferation relative to that of cells transfected with negative control siRNA in 2 out of 2 donors. Addition of recombinant ENPP1-Fc protein restored ENPP1- associated proliferation in all donors (8099.75 ±134.32 (untreated) vs 1478 ± 55.34 (5ug/ml ENPP1-Fc treated, P<0.001)). In contrast, bisphosphonates, a current off-label treatment for patients with GACI, had no effect on cellular proliferation. Increased levels of PPi were also detected in culture supernatants obtained from cells treated with the ENPP1-Fc protein. Conclusion: For the first time, we have demonstrated that ENPP1 knockdown promotes proliferation of human VSMCs, and treatment with a functionally active ENPP1-Fc protein significantly inhibits ENPP1-associated proliferation. These results suggest that ENPP1 enzyme replacement may be a potential strategy to treat myointimal proliferation in patients with GACI disease.

OS 02-07 WNT5A/ROR2 SUPPRESSES THE PROLIFERATION OF SMOOTH MUSCLE CELL VIA PKC SIGNALING PATHWAY

Objective: Hypertension is closely associated with profound vascular remodeling, especially proliferation and hyperplasia of vascular smooth muscle cells (VSMCs). Aberrant Wnt5a signaling has been related to vascular diseases, but its role on the proliferation of VSMCs is unclear. The study evaluated the effect of Wnt5a on the proliferation of VSMCs and its possible mechanism. Design and Method: The capability of cell proliferation was detected by the assays of MTT, colony formation and EdU cell proliferation. Flow cytometry detections were applied to evaluate the cell cycle. The expressions of specific proteins were detected by western blotting. Immunofluorescence analysis was utilized to observe the localization of Wnt5a and Ror2. Results: The data show that serum induced proliferation of VSMC in a time-dependent manner, accompanied with a significant decrease of Wnt5a expression. Treatment with recombinant mouse Wnt5a or overexpression of Wnt5a leads to the proliferative inhibition of VSMCs and cell cycle arrest at G0/G1 phase, which related to the down-regulation of CyclinD1 and up-regulation of p53. Whereas knockdown of Wnt5a has an opposite effect. Both of Wnt5a and Ror2 are co-localized in the membrane surface. Additionally, knockdown of Ror2 decreases Wnt5a expression and the phenotype of cell proliferation induced by Wnt5a overexpression are rescued. Moreover, Wnt5a promotes Ror2 expression, which has been shown to specifically interact with the non-canonical Wnt signaling pathway. Therefore, protein kinase C (PKC) signaling was activated by Wnt5a in VSMCs, which was also accompanied with upregulation of p53 and reduction of CyclinD1. A positive feedback loop between Wnt5a and phospho-PKC to regulate CyclinD1 expression was also revealed. Furthermore, knockdown of p53 dramatically increases CyclinD1 expression. Conclusions: Taken together, Wnt5a exerts its beneficial effects on VSMCs proliferation and vascular remodeling. Wnt5a/Ror2/PKC signaling pathway is involved in suppression of VSMC proliferation by down-regulating and up-regulating the expression of CyclinD1 and p53 respectively.

Abstract P303: Cilostazol Attenuates Angii-induced Cardiac Fibrosis in Mice

Background: Cilostazol, a phosphodiesterase-3 inhibitor, plays vasoprotective roles such as an improvement of endothelial function, a vasodilatation and a suppression of proliferation of vascular smooth muscle cells. The aim of study was to investigate a cardioprotective effect of cilostazol. Method: Male apolipoprotein E deficient mice (8-12 weeks old) were fed with either normal chow diet or cilostazol-containing (0.1% wt/v) diet. After 1 week of cilostazol administration, mice were infused subcutaneously with either angiotensin II (AngII, 1,000 ng/kg/min, n = 16 - 19) or saline (n = 5 - 6) by osmotic minipumps for 4 weeks. Results: AngII equivalently increased systolic blood pressure, irrespective of cilostazol administration. Cilostazol had no effect on serum cholesterol concentrations, triglycerides, high-density lipoprotein-cholesterol, body weights, heart rates, and systolic blood pressures. AngII increased heart weight but was attenuated by cilostazol administration (6.7±0.8 to 6.0±0.7 mg/gBW, p < 0.05). Cilostazol prevented both perivascular and interstitial cardiac fibrosis induced by AngII (p < 0.05, each). Quantitative real-time PCR revealed that mRNA expressions of Ctgf , Collagen I , Collagen III , Tgf- , Hgf and Spp-1 increased by AngII infusion but were attenuated by cilostazol administration (p < 0.05). Immunohistochemical analysis demonstrated that AngII administration enhanced OPN expression in heart but was suppressed by cilostazol administration. Further, to investigate the mechanism, human cardiac myocytes were cultured and stimulated with AngII (1x10 -7 M). Co-treatment of Cilostazol (1x10 -7 to 1x10 -5 M) attenuated AngII-induced increase of Spp-1 gene expression in dose-dependent manner. This effect was mimic by a treatment with forskolin, which was diminished by co-treatment with H-89. Conclusion: Cilostazol attenuated AngII-induced cardiac fibrosis in vivo. Cilostazol attenuated AngII-induced increment of Spp-1 gene expression through cAMP-PKA dependent pathway.

Abstract 308: Differential Regulation of Alpha1a-adrenergic Receptor and its Genetic Variant Signaling by Novel Spinophilin-RGS2 Signalosome in Human Cells

α 1- adrenergic receptors (α 1a , α 1b , α 1d ), members of G protein-coupled receptor (GPCR) family, regulate stress-facilitated changes in the cardiovascular (CV) system and human blood pressure (BP) via smooth muscle cell (SMC) proliferation and vasoconstriction. The α 1a AR is the predominant subtype in human heart and resistance vessels. The α 1a AR G247R (247R) genetic variant was discovered in a patient with severe hypertension and in a cohort of patients enriched for CV disorders. We reported a unique coupling of this genetic variant to βarrestin/MMP/EGFR transactivation pathway in rat fibroblasts, cardiomyoblasts and vascular SMCs leading to hyperproliferation and hypertrophy. Here we present that differential interaction of 247R or α 1a AR (WT) with scaffolding/regulatory proteins mediate unique signaling of 247R. Physiological levels of 247R but not WT upregulate endogenous levels of scaffolding protein spinophilin (SPL) in rat SMCs and cardiomyoblasts. SPL knockdown or overexpression of RGS2 (negative R egulators of G -protein S ignaling) inhibits 247R-mediated hyperproliferation. Overexpression of SPL with RGS2 restores hyperproliferation suggesting that SPL binds RGS2 and prevents 247R-RGS2 interaction. To determine if 247R hyperproliferation is in effect in human cells, we generated human iPSCs from primary fibroblasts and differentiated them to SMCs with characteristic morphology and expression of SMC markers (RT-PCR at various passages). Consistent with our findings in rat cells, expression of 247R but not WT in hiPSC-derived SMCs triggered ~70% increased proliferation. Agonist treatment resulted in increased hypertrophy in 247R cells compared with WT. Co-immunoprecipitation from HEK293 cells expressing HA-α 1 ARs and full length Myc-SPL or Flag-RGS2 revealed that SPL exhibits ~2-fold stronger interaction with WT than with 247R. Consequently, SPL recruits RGS2 and inhibits receptor signaling. In contrast, weaker SPL-247R interaction results in diminished RGS2 inhibitory effect allowing hyperproliferation of 247R cells. Thus, we identify novel SPL/RGS2 signalosome responsible for α 1a AR signaling in human cells and identify SPL as a potential novel target for treatment of α 1 AR-mediated human CV disorders.

Effects of Astragaloside IV on tumor necrosis factor-α-induced expressions of matrix metalloproteinases in rat vascular smooth muscle cells

Objective To investigate the effect of Astragaloside IV (AS-IV) on tumor necrosis factor-α (TNF-α)-induced expressions of matrix metalloproteinases (MMPs) in a rat vascular smooth muscle cells (VSMCs) proliferation model and its mechanism. Methods VSMCs were prepared from the thoracoabdominal aorta of rats by using issue-sticking method. Morphology of cells was observed by inverted microscope, and identified by immunohistochemical methods with antibody against SM-α-actin. The model of VSMCs proliferation and migration was established by TNF-α inducer in vitro, and randomly divided into the following groups: the control group, the TNF-α group, the TNF-α+ AS-IV (0.5 μg/ml) group, the TNF-α+ AS-IV (5 μg/ml) group, the TNF-α+ AS-IV (25 μg/ml) group, and the TNF-α+ AS-IV (50 μg/ml) group. The effect of AS-IV on TNF-α-induced VSMCs proliferation activity was detected by the caerulein and cholecystokinin octapeptide (CCK-8) method. The quantitative real-time polymerase chain reaction (real-time PCR) and Western blotting were used to examine the effects of AS-IV on the VSMCs-secreted mRNA and protein expressions of matrix metalloproteinase-2 (MMP-2), respectively. Results The proliferative activity, migratory distance and invasive capacity of VSMCs were obviously increased in TNF-α stimulation group versus in control group (all P<0.01), which suggested that TNF-α can promote VSMCs proliferation and migration, and that the rat model of VSMCs proliferation in vitro was successfully established. The results of CCK-8 tests showed that VSMCs proliferation was obvious and the optical density (OD) value was elevated (P<0.01) after a preset time incubation with TNF-α. VSMCs proliferation was inhibited in each AS-IV treatment group, and the OD value was decreased as compared with the TNF-α group. And the inhibitive effect was increased along with the increments of AS-IV concentration and the acting time, which indicated that AS-IV can inhibit TNF-α-induced VSMCs proliferation in a time- and dose-dependent manner. The results of real-time PCR and Western blotting assays indicated that TNF-α changed the ratio of MMPs to the tissue inhibitors of metalloproteinases (TIMPs) by down-regulating active MMP-2 expression without influencing proMMP-2 and TIMP-2 expressions, and thus promoted the degradation of ECM. AS-IV (0.5-50 μg/ml) inhibited VSMCs proliferation and migration by down-regulating the TNF-α-induced MMP-2 overexpression in a dose-dependent manner, up-regulating the mRNA and protein expressions of TIMP-2, and modulating the ratio of MMPs to TIMPs, thereby inhibited the degradation of ECM. Conclusions AS-IV inhibits VSMCs proliferation and migration in a time- and dose-dependent manner. AS-IV inhibits VSMCs proliferation and migration by down-regulating TNF-α-induced MMP-2 overexpression, up-regulating TIMP-2 expressions, and normalizing the ratio of MMPs to TIMPs. Therefore, AS-IV inhibits the degradation of ECM, which may play a role in the prevention and treatment of in-stents restenosis after PCI. Key words: Astragalus; Muscle, smooth, vascular; Tumor necrosis factor-alpha; Matrix

Relevant factors of pulmonary arterial smooth muscle cells proliferation and pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a disease of unknown etiology that leads to a progressive increase in pulmonary vascular resistance (PVR), if untreated, ultimately right heart failure and high mortality.It is concerted pulmonary vascular contraction and vascular remodeling are the 2 main courses of physiology and pathology leading to PAH, especially the significant role of proliferation of pulmonary arterial smooth muscle cells.A lot of relevant factors are revealed to take a participation into regulating the proliferation of pulmonary arterial smooth muscle cells and finally PAH. Key words: Pulmonary arterial smooth muscle cell; Cell proliferation; Relevant factor; Pulmonary arterial hypertension

Poor maternal nutrition during gestation alters the expression of genes involved in muscle development and metabolism in lambs.

Poor maternal nutrition during gestation can result in reduced muscle mass and increased adiposity of the muscle tissue in the offspring. This can have long-lasting consequences on offspring health and productivity. However, the mechanisms by which poor maternal nutrition affects postnatal muscle development are poorly understood. We hypothesized that poor maternal nutrition during gestation would alter expression of key pathways and genes involved in growth, development, and maintenance of the muscle of lambs. For this study, beginning at d 31 ± 1.3 of gestation, ewes were fed 100 (control), 60 (restricted), or 140% (overfed) of the NRC requirements. Within 24 h of birth, lambs were necropsied and semitendinosus muscle tissue was collected for gene expression analysis. Using RNA sequencing (RNA-seq) across dietary treatment groups, 35 and 10 differentially expressed genes were identified using the and reference annotations, respectively. Maternal overfeeding caused changes in the expression of genes involved in regulating muscle protein synthesis and growth as well as metabolism. Alternately, maternal nutrient restriction affected genes that are involved in muscle cell proliferation and signal transduction. That is, despite a similar phenotype, the genes identified differed between offspring born to restricted- or overfed, ewes indicating that the mechanism for the phenotypic changes in muscle are due to different mechanisms.

Convergent evidence from systematic analysis of GWAS revealed genetic basis of esophageal cancer.

Recent genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) associated with risk of esophageal cancer (EC). However, investigation of genetic basis from the perspective of systematic biology and integrative genomics remains scarce.In this study, we explored genetic basis of EC based on GWAS data and implemented a series of bioinformatics methods including functional annotation, expression quantitative trait loci (eQTL) analysis, pathway enrichment analysis and pathway grouped network analysis.Two hundred and thirteen risk SNPs were identified, in which 44 SNPs were found to have significantly differential gene expression in esophageal tissues by eQTL analysis. By pathway enrichment analysis, 170 risk genes mapped by risk SNPs were enriched into 38 significant GO terms and 17 significant KEGG pathways, which were significantly grouped into 9 sub-networks by pathway grouped network analysis. The 9 groups of interconnected pathways were mainly involved with muscle cell proliferation, cellular response to interleukin-6, cell adhesion molecules, and ethanol oxidation, which might participate in the development of EC.Our findings provide genetic evidence and new insight for exploring the molecular mechanisms of EC.

Preliminary study of artificial synthetic E-selectin inhibits the proliferation mechanism of vascular smooth muscle cells in rats

Objective To preliminary study the mechanism of artificial synthetic E-selectin inhibiting the proliferation of vascular smooth muscle cells in rats. Methods Ninety adult male SD rats were randomly divided into 3 groups: a control group, an operation group, and a treatment group (n=30 in each group). The right common carotid artery was made a longitudinal incision and interrupted suture in the operation group and the treatment group, and the control group did not make vascular incision and suture. Artificial synthetic E-selectin and the same amount of saline were injected into the femoral veins of the rats respectively in the treatment group and the operation group after vascular suture. On day 1, 3, 7, and 14 after procedure, ELISA was used to detect the concentrations of serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The vascular tissue at the suture was taken. Western blot and RT-PCR were used to detect the protein level of NF-κB p65 and mRNA expression. Electrophoretic mobility shift assay was used to detect the NF-κB transcriptional activity. Immunohistochemical staining was used to detect the positive cell rate of proliferating cell nuclear antigen (PCNA). Results The concentrations of serum TNF-α and IL-6 and the levels of NF-κB p65 protein and mRNA began to increase at day 1 after vascular suture in the operation group and the treatment group. They reached the peak at day 3, and they were still higher than those in the control group at day 7 (P 0.05). The NF-κB transcription activity in the operation group was higher than that in the treatment group at day 3 after suture (P<0.01). The PCNA positive cells began to express at day 3 after vascular suture in the operation group and the treatment group. The expression of PCNA positive cells in the control group was not obvious or no expression. There were significant differences among the 3 groups (P<0.05). They still expressed high at day 7 and 14 (P<0.01), while the expression of PCNA positive cells was lower than that in the treatment group over the same period (P<0.01). Conclusion Artificial synthetic E-selectin can inhibit the proliferation of vascular smooth muscle cells by inhibiting NF-κB activity. Key words: E-selectin; NF-kappa B; Myocytes, smooth muscle; Cell proliferation; Rats; Vessels

Epothilones Suppress Neointimal Thickening in the Rat Carotid Balloon-Injury Model by Inducing Vascular Smooth Muscle Cell Apoptosis through p53-Dependent Signaling Pathway.

Microtubule stabilizing agents (MTSA) are known to inhibit vascular smooth muscle cell (VSMC) proliferation and migration, and effectively reduce neointimal hyperplasia and restenosis. Epothilones (EPOs), non-taxane MTSA, have been found to be effective in the inhibition of VSMC proliferation and neointimal formation by cell cycle arrest. However, effect of EPOs on apoptosis in hyper-proliferated VSMCs as a possible way to reduce neointimal formation and its action mechanism related to VSMC viability has not been suited yet. Thus, the purposes of the present study was to investigate whether EPOs are able to inhibit neointimal formation by inducing apoptosis within the region of neointimal hyperplasia in balloon-injured rat carotid artery, as well as underlying action mechanism. Treatment of EPO-B and EPO-D significantly induced apoptotic cell death and mitotic catastrophe in hyper-proliferated VSMCs, resulting in cell growth inhibition. Further, EPOs significantly suppressed VSMC proliferation and induced apoptosis by activation of p53-dependent apoptotic signaling pathway, Bax/cytochrome c/caspase-3. We further demonstrated that the local treatment of carotid arteries with EPOs potently inhibited neointimal lesion formation by induction of apoptosis in rat carotid injury model. Our findings demonstrate a potent anti-neointimal hyperplasia property of EPOs by inducing p53-depedent apoptosis in hyper-proliferated VSMCs.