scholarly journals Cytokine-Mediated Downregulation of Coxsackievirus-Adenovirus Receptor in Endothelial Cells

2004 ◽  
Vol 78 (15) ◽  
pp. 8047-8058 ◽  
Author(s):  
Theresa Vincent ◽  
Ralf F. Pettersson ◽  
Ronald G. Crystal ◽  
Philip L. Leopold
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Protein Expression ◽  
Western Blot ◽  
Inflammatory Cytokines ◽  
Cell Physiology ◽  
Mrna Levels ◽  
Cytokine Treatment ◽  
Adenovirus Receptor ◽  
The Impact

ABSTRACT Endothelial cells have the ability to change their complement of cell surface proteins in response to inflammatory cytokines. We hypothesized that the expression of the coxsackievirus-adenovirus receptor (CAR), a viral receptor and putative cell-cell adhesion molecule, may be altered during the response of endothelial cells to inflammation. To test this hypothesis, we evaluated CAR protein and mRNA levels in human umbilical vein endothelial cells after they were exposed to tumor necrosis factor alpha, gamma interferon, or a combination of the two cytokines. Flow cytometric and Western blot analyses indicated that cytokine treatment led to a synergistic decrease in CAR protein expression. A Western blot analysis showed that CAR levels decreased to 16% ± 4% or 1% ± 4% of the CAR protein levels in untreated cells with either 24 or 48 h of cytokine treatment, respectively. Quantitative reverse transcription-PCR demonstrated that the combination treatment caused CAR mRNA levels to decrease to 21% ± 12% or 5% ± 3% of the levels in untreated cells after a 24- or 48-h cytokine treatment, respectively. Reduced CAR expression led to a decrease in adenovirus (Ad) binding of 80% ± 3% (compared with untreated endothelial cells), with a subsequent decrease in Ad-mediated gene transfer that was dependent on the dose and duration of cytokine treatment but not on the dose of Ad. A similar decrease in CAR protein level and susceptibility to Ad infection was observed in human microvascular endothelial cells, while CAR expression on normal human bronchial epithelial cells or A549 lung epithelial cells was less affected by cytokine treatments. Taken together, the data demonstrate that inflammatory cytokines decrease CAR mRNA and protein expression with a concomitant decrease in Ad binding, reflecting the impact of cell physiology on the function of CAR and the potential effect of inflammation on the ability of Ad to transfer genes to endothelial cells.

scholarly journals Caffeine induces endothelial tissue factor expression via phosphatidylinositol 3-kinase inhibition

2012 ◽  
Vol 107 (05) ◽  
pp. 884-894 ◽  
Author(s):  
Erik W. Holy ◽  
Giovanni G. Camici ◽  
Alexander Akhmedov ◽  
Simon F. Stämpfli ◽  
Barbara E. Stähli ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Expression ◽  
Tissue Factor ◽  
Surface Activity ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Phosphatidylinositol 3 Kinase ◽  
Tnf Α ◽  
The Impact ◽  
Phosphatidylinositol 3

SummaryTissue factor (TF) is the key activator of coagulation and is involved in acute coronary syndromes. Caffeine is often reported to increase cardiovascular risk; however, its effect on cardiovascular morbidity and mortality is controversial. Hence, this study was designed to investigate the impact of caffeine on endothelial TF expression in vitro. Caffeine concentration-dependently enhanced TF protein expression and surface activity in human endothelial cells stimulated by tumour necrosis factor (TNF)-α or thrombin. Caffeine inhibited phosphatidylinositol 3-kinase (PI3K) activity and this effect was comparable to that of the known PI3K inhibitor LY294002. Consistently, treatment of endothelial cells with LY294002 enhanced TNF-α induced TF expression to a similar extent as caffeine, and adenoviral expression of the active PI3K mutant (p110) reversed the effect of both caffeine and LY294002 on TF expression. Caffeine and LY294002 increased DNA binding capacity of the transcription factor nuclear factor κB, whereas the activation pattern of mitogen-activated protein kinases (MAPK) remained unaltered. Luciferase reporter assay revealed a caffeine dependent activation of the TF promoter, and RT-PCR revealed a dose dependent increase in TF mRNA levels when stimulated with caffeine in the presence of TNF-α. In conclusion, caffeine enhances TNF-α-induced endothelial TF protein expression as well as surface activity by inhibition of PI3K signalling. Since the caffeine concentrations applied in the present study are within the plasma range measured in humans, our findings indicate that caffeine enhances the prothrombotic potential of endothelial cells and underscore the importance of PI3K in mediating these effects.

Abstract 294: Expression of Matrix Metalloproteases during the Differentiation of Porcine Adopse-Drived Mesenchymal Stem Cells ro Endothelial Cells

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Sami G Almalki ◽  
Velidi Rao ◽  
Divya Pankajakshan ◽  
Devendra K Agrawal
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Mesenchymal Stem Cells ◽  
Enzyme Activity ◽  
Protein Expression ◽  
Western Blot ◽  
Gelatin Zymography ◽  
Matrix Metalloproteases ◽  
Positive Staining ◽  
Mrna Transcripts

Rationale Adipose-derived mesenchymal stem cells (ADMSCs) are multipotent cells that have the potential to differentiate into different cell linages, and represent promising tools in various clinical applications. However, the molecular mechanisms that control the ability of ADMSCs to remodel 3-dimensional extracellular matrix (ECM) barriers during differentiation are not clearly understood. Herein, we studied the expression of matrix metalloproteinases (MMPs) during the differentiation of ADMSCs to endothelial cells (ECs) in vitro . Methods MSCs were isolated from porcine abdominal adipose tissue, and characterized by positive staining for MSC markers, CD44, CD73, CD90, and negative staining for CD11b, CD34 and CD45. The plasticity of MSCs was detected by bi-lineage differentiation to osteocytes, and adipocytes. The mRNA transcripts for different MMPs and TIMPs and protein expression of EC markers were analyzed by RT-PCR and immunostaining. The enzyme activity and protein expression were also analyzed by gelatin zymography, ELISA, and Western blot. Results The differentiation of ADMSCs to ECs was confirmed by the positive staining and mRNA expression of the endothelial markers. The mRNA transcripts for MMP-2 and membrane type 1 MMP (MT1-MMP) was significantly increased by 2.5 and 2.0 fold, respectively, during the differentiation of MSCs into ECs. Western blot and ELISA showed an elevated MT1-MMP and MMP-2 expression. The enzyme activity of MMP-2 was also observed by gelatin zymography. Conclusion We demonstrated that porcine ADMSCs have the ability to differentiate into ECs, and this process involves the up-regulation of MMP-2 and MT1-MMP. The increase in the expression of MMP-2 and MT1-MMP may, at least partially, facilitate the change in morphology of MSCs by degrading the ECM barriers. These findings may provide a potential mechanism for the role of MMP2 and MT1-MMP in the differentiation of ADMSCs into ECs.

Disparate cytokine regulation of ICAM-1 in rat alveolar epithelial cells and pulmonary endothelial cells in vitro

1995 ◽  
Vol 269 (1) ◽  
pp. L127-L135 ◽  
Author(s):  
W. W. Barton ◽  
S. Wilcoxen ◽  
P. J. Christensen ◽  
R. Paine
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Inflammatory Cytokines ◽  
Alveolar Epithelial Cells ◽  
Normal Lung ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Epithelial

Intercellular adhesion molecule-1 (ICAM-1) is expressed at high levels on type I alveolar epithelial cells in the normal lung and is induced in vitro as type II cells spread in primary culture. In contrast, in most nonhematopoetic cells ICAM-1 expression is induced in response to inflammatory cytokines. We have formed the hypothesis that the signals that control ICAM-1 expression in alveolar epithelial cells are fundamentally different from those controlling expression in most other cells. To test this hypothesis, we have investigated the influence of inflammatory cytokines on ICAM-1 expression in isolated type II cells that have spread in culture and compared this response to that of rat pulmonary artery endothelial cells (RPAEC). ICAM-1 protein, determined both by a cell-based enzyme-linked immunosorbent assay and by Western blot analysis, and mRNA were minimally expressed in unstimulated RPAEC but were significantly induced in a time- and dose-dependent manner by treatment with tumor necrosis factor-alpha, interleukin-1 beta, or interferon-gamma. In contrast, these cytokines did not influence the constitutive high level ICAM-1 protein expression in alveolar epithelial cells and only minimally affected steady-state mRNA levels. ICAM-1 mRNA half-life, measured in the presence of actinomycin D, was relatively long at 7 h in alveolar epithelial cells and 4 h in RPAEC. The striking lack of response of ICAM-1 expression by alveolar epithelial cells to inflammatory cytokines is in contrast to virtually all other epithelial cells studied to date and supports the hypothesis that ICAM-1 expression by these cells is a function of cellular differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Identification of Nesfatin-1 in Human and Murine Adipose Tissue: A Novel Depot-Specific Adipokine with Increased Levels in Obesity

Endocrinology ◽  
2010 ◽  
Vol 151 (7) ◽  
pp. 3169-3180 ◽  
Author(s):  
Manjunath Ramanjaneya ◽  
Jing Chen ◽  
James E. Brown ◽  
Gyanendra Tripathi ◽  
Manfred Hallschmid ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Protein Expression ◽  
Food Deprivation ◽  
Inflammatory Cytokines ◽  
Energy Homeostasis ◽  
Culture Media ◽  
Nonesterified Fatty Acid ◽  
High Fat ◽  
Gene And Protein Expression ◽  
The Impact

Nesfatin-1 is a recently identified anorexigenic peptide derived from its precursor protein, nonesterified fatty acid/nucleobindin 2 (NUCB2). Although the hypothalamus is pivotal for the maintenance of energy homeostasis, adipose tissue plays an important role in the integration of metabolic activity and energy balance by communicating with peripheral organs and the brain via adipokines. Currently no data exist on nesfatin-1 expression, regulation, and secretion in adipose tissue. We therefore investigated NUCB2/nesfatin-1 gene and protein expression in human and murine adipose tissue depots. Additionally, the effects of insulin, dexamethasone, and inflammatory cytokines and the impact of food deprivation and obesity on nesfatin-1 expression were studied by quantitative RT-PCR and Western blotting. We present data showing NUCB2 mRNA (P < 0.001), nesfatin-1 intracellular protein (P < 0.001), and secretion (P < 0.01) were significantly higher in sc adipose tissue compared with other depots. Also, nesfatin-1 protein expression was significantly increased in high-fat-fed mice (P < 0.01) and reduced under food deprivation (P < 0.01) compared with controls. Stimulation of sc adipose tissue explants with inflammatory cytokines (TNFα and IL-6), insulin, and dexamethasone resulted in a marked increase in intracellular nesfatin-1 levels. Furthermore, we present evidence that the secretion of nesfatin-1 into the culture media was dramatically increased during the differentiation of 3T3-L1 preadipocytes into adipocytes (P < 0.001) and after treatments with TNF-α, IL-6, insulin, and dexamethasone (P < 0.01). In addition, circulating nesfatin-1 levels were higher in high-fat-fed mice (P < 0.05) and showed positive correlation with body mass index in human. We report that nesfatin-1 is a novel depot specific adipokine preferentially produced by sc tissue, with obesity- and food deprivation-regulated expression.

Abstract W P359: Activation of Prostacyclin Receptor (IP) in Human Brain Microvascular Endothelial Cells Stimulates Production of SAPPa

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Tongrong He ◽  
Tong Lu ◽  
Zvinomir Katusic
Keyword(s):  
Endothelial Cells ◽  
Protein Expression ◽  
Human Brain ◽  
Microvascular Endothelial Cells ◽  
Mrna Levels ◽  
Brain Microvascular Endothelial Cells ◽  
Camp Pathway ◽  
Processing Enzyme ◽  
Amyloidogenic Processing ◽  
Adam10 Expression

Previous studies have established that cerebral blood vessels possess high capacity to synthesize prostacyclin (PGI 2 ). Substantial evidence indicates that amyloid precursor protein (APP) and soluble APPα (sAPPα) have neurotrophic and nueroprotective properties. We hypothesized that activation of IP-cAMP pathway stimulates non-amyloidogenic processing of APP in cerebral endothelial cells. Western blotting was used to detect protein expression; real time RT-PCR was employed to measure mRNA levels of APP, and a disintegrin and metalloprotease 10 (ADAM10, an α processing enzyme); sAPPα secretion was detected in condition medium derived from culturing human brain microvascular endothelial cells (BMVECs), by ELISA. After human BMVECs were treated with PGI 2 analog iloprost (0.01, 0.05, 0.1, or 0.5 μM) for 3 days, protein levels of ADAM10 (n=7-9, P<0.05) and APP (n=6, P<0.05) were significantly increased in a concentration dependent manner, while β amyloidogenic processing enzyme BACE1, and other α processing enzymes such as ADAM9 and ADAM17 were not changed. mRNA levels of APP (n=7, P<0.05) and ADAM10 (n=4, P<0.05), as well as sAPPα production in human BMVECs (n=6, P<0.05) were also significantly augmented in response to iloprost treatment. Moreover, stimulation of human BMVECs with forskolin (40μM) significantly enhanced APP and ADAM10 protein expression. Most notably, iloprost significantly augmented protein expression of peroxisome proliferation-activated receptor-δ (PPARδ) and SIRT1. We further explored the role of PPARδ in APP processing. ADAM10 expression (n=6, P<0.05), but not APP and BACE1, was significantly increased in human BMVECs treated with PPARδ ligand GW501516 (30 or 100 nM). GW501516 (100 nM) also significantly increase sAPPα production (n=9-10, P<0.05). siRNA against PPARδ significantly suppressed basal levels of ADAM10, and blocked iloprost-induced ADAM10 expression (n=4, P<0.05). These findings suggest that activation of IP-cAMP pathway enhances non-amyloidogenic processing of APP and consequently increases production of neurotrophic molecule sAPPα in human BMVECs. Activation of PPARδ in part mediates iloprost-induced α processing of APP.

scholarly journals Low Shear Stress Upregulates CX3CR1 Expression by Inducing VCAM-1 via the NF-κB Pathway in Vascular Endothelial Cells

2020 ◽  
Vol 78 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Yiwei Zhao ◽  
Peile Ren ◽  
Qiufang Li ◽  
Shafiu Adam Umar ◽  
Tan Yang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Protein Expression ◽  
Vascular Endothelial Cells ◽  
Critical Role ◽  
Mrna Levels ◽  
Vascular Endothelial ◽  
Low Shear Stress ◽  
Low Shear ◽  
Cx3cr1 Expression

Abstract Atherosclerosis is a significant cause of mortality and morbidity. Studies suggest that the chemokine receptor CX3CR1 plays a critical role in atherogenesis. Shear stress is an important mechanical force that affects blood vessel function. In this study, we investigated the effect of shear stress on CX3CR1 expression in vascular endothelial cells (VECs). First, cells were exposed to different shear stress and then CX3CR1 mRNA and protein were measured by quantitative RT-PCR and western blot analysis, respectively. CX3CR1 gene silencing was used to analyze the molecular mechanisms underlying shear stress-mediated effects on CX3CR1 expression. CX3CR1 mRNA and protein expression were significantly increased with 4.14 dyne/cm2 of shear stress compared with other tested levels of shear stress. We observed a significant increase in CX3CR1 mRNA levels at 2 h and CX3CR1 protein expression at 4 h. CX3CR1-induced VCAM-1 expression in response to low shear stress by activating NF-κB signaling pathway in VECs. Our findings demonstrate that low shear stress increases CX3CR1 expression, which increases VCAM-1 expression due to elevated NF-κB activation. The current study provides evidence of the correlation between shear stress and atherosclerosis mediated by CX3CR1.

Effects of Fluvastatin on the Expression of Tissue Factor Pathway Inhibitor in Human Umbilical Vein Endothelial Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2253-2253
Author(s):  
Keiko Maruyama ◽  
Eriko Morishita ◽  
Hiroki Torishima ◽  
Akiko Sekiya ◽  
Hidesaku Asakura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Expression ◽  
Western Blot ◽  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Umbilical Vein ◽  
The Other ◽  
Mrna And Protein Expression ◽  
Tissue Factor Pathway ◽  
Umbilical Vein Endothelial Cells

Abstract Abstract 2253 OBJECTIVE: 3-Hydroxyl-3-methyl coenzyme A reductase inhibitors (statins) inhibit the production of mevalonate and other isoprenoid intermediates of the cholesterol biosynthetic pathway, such as farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP). Statins can protect the vasculature from inflammation and atherosclerosis caused by cholesterol-dependent and cholesterol-independent mechanisms. The latest investigations show that statins modulate the expression of genes related to inflammation, blood coagulation and fibrinolysis in cultured endothelial cells. Tissue factor pathway inhibitor (TFPI) which is expressed by endothelial cells plays a crucial role in hemostasis by regulating TF-induced initiation of coagulation. The aim of this study was to elucidate the effects of fluvastatin, lipophilic statin, on expressions of TFPI in human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were incubated for 24 h in culture medium including fluvastatin (0.1, 1.0, 10.0 μM). The expression of TFPI mRNA and protein was evaluated by western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. To identify which product of statin reaction is necessary for the effect of fluvastatin, HUVECs were incubated for 24h with fluvastatin with mavalonate, FPP, or GGPP. On the other hand, it is known that fluvastatin increase nitric oxide (NO) bioavailability. To determine whether fluvastatin induced NO affects TFPI mRNA and protein expression, HUVECs were incubated for 24h with fluvastatin with NG-Nitro-L-arginine methyl ester, hydrochloride (L-NAME: specific inhibitor of NO synthase). Additionally, to determine whether fluvastatin affects p38MAPK, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), phosphoinositide 3-kinase (PI3K), and protein kinase C (PKC) pathways, HUVECs were incubated for 24h with fluvastatin with the inhibitors of p38MAPK (SB203580), JNK (SP600125), MEK (U0126), PI3K (LY294002), and PKC (GF109203). The expression of TFPI mRNA and protein was evaluated by western blot. RESULTS: Fluvastatin increased TFPI mRNA and protein expression (1μM: p<0.01, 10μM: p<0.05; Figure 1). This fluvastatin-dependent up-regulation of TFPI was prevented by mevalonate and geranylgeranylphosphate (GG-PP). In contrast, the addition of L-NAME did not alter induction of TFPI expression by fluvastatin. Similarly, Y-27632 (Rho kinase inhibitor) and NSC23766 (Rac1 inhibitor) were ineffective. Additionally, the inhibitors of p38MAPK, PI3K, and PKC prevented fluvastatin-dependent up-regulation. On the other hand, the inhibitors of JNK and MEK were ineffective. CONCLUSIONS: This study suggests that fluvastatin significantly increases TFPI mRNA and protein expression, and this effect of fluvastatin is accompanied by the activation of p38 MAPK, PI3K, and PKC pathways. Therefore, this effect may play an important role in preventing cardiovascular events. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Escin Increases the Survival Rate of LPS-Induced Septic Mice Through Inhibition of HMGB1 Release from Macrophages

2015 ◽  
Vol 36 (4) ◽  
pp. 1577-1586 ◽  
Author(s):  
Yajun Cheng ◽  
Hongrui Wang ◽  
Min Mao ◽  
Chao Liang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Survival Rate ◽  
Western Blot ◽  
Inflammatory Cytokines ◽  
Molecular Mechanisms ◽  
Post Treatment ◽  
Mrna Levels ◽  
Treatment Methods ◽  
Protein Levels ◽  
Qrt Pcr ◽  
Pro Inflammatory Cytokines

Background: Previous studies have described the effects of Escin on improving the survival rate of endotoxemic animals. The purpose of this study was to explore the molecular mechanisms of this potentially beneficial treatment. Methods: First, the survival rate of endotoxemic mice was monitored for up to 2 weeks after Escin pretreatment, Escin post-treatment, or Escin post-treatment + rHMGB1. The effects of Escin on the release of pro-inflammatory cytokines such as TNF-a, IL-1ß, IL-6 and HMGB1 in the serum of endotoxemic mice and LPS-induced macrophages were evaluated by ELISA. Furthermore, the mRNA and protein levels of HMGB1 in LPS-induced macrophages were measured by qRT-PCR and Western blot, respectively. Additionally, the release of pro-inflammatory cytokines such as TNF-a, IL-1ß, IL-6 was evaluated by ELISA in rHMGB1-induced macrophages. Finally, the protein levels and the activity of NF-κB in macrophages were checked by Western blot and ELISA, respectively. Results: Both pretreatment and post-treatment with Escin could improve the survival rate of endotoxemic mice, while exogenous rHMGB1 reversed this effect. In addition, Escin decreased the level of the pro-inflammatory cytokines TNF-a, IL-1ß, IL-6 and HMGB1 in endotoxemic mice and in LPS-induced macrophages. Escin could also inhibit the mRNA levels and activity of HMGB1. The release of the pro-inflammatory cytokines TNF-a, IL-1ß, IL-6 could be suppressed in rHMGB1-induced macrophages by Escin. Finally, Escin could suppress the activation of NF-κB in LPS-induced macrophages. Conclusion: Escin could improve the survival of mice with LPS-induced endotoxemia. This effect maybe meditated by reducing the release of HMGB1, resulting in the suppression of the release of pro-inflammatory cytokines.

scholarly journals Mobilization of TLR4 Into Lipid Rafts by Aggregatibacter Actinomycetemcomitans in Gingival Epithelial Cells

2016 ◽  
Vol 39 (5) ◽  
pp. 1777-1786 ◽  
Author(s):  
Haruka Imai ◽  
Tsuyoshi Fujita ◽  
Mikihito Kajiya ◽  
Kazuhisa Ouhara ◽  
Tetsuya Yoshimoto ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Map Kinase ◽  
Lipid Rafts ◽  
Inflammatory Cytokines ◽  
Aggregatibacter Actinomycetemcomitans ◽  
P38 Map Kinase ◽  
Mrna Levels ◽  
Periodontal Pathogens ◽  
Gingival Epithelial Cells ◽  
Tnf Α

Background: An investigation of the mechanisms underlying the production of inflammatory cytokines through the stimulation of microorganisms on gingival epithelial cells may provide insights into the pathogenesis of the initiation of periodontitis. Lipid rafts, microdomains in the cell membrane, include a large number of receptors, and are centrally involved in signal transduction. We herein examined the involvement of lipid rafts in the expression of interleukin (IL-6) and IL-8 in gingival epithelial cells stimulated by periodontal pathogens. Methods: OBA9, a human gingival cell line, was stimulated by Aggregatibacter actinomycetemcomitans or tumor necrosis factor (TNF)-α in the presence of methyl-β-cyclodextrin (MβCD). Results: A. actinomycetemcomitans or TNF-α increased IL-8 and IL-6 mRNA levels, and promoted the phosphorylation of ERK and p38 MAP kinase in OBA9. The pretreatment with MβCD abolished increases in IL-6 and IL-8 mRNA levels and the phosphorylation induced by A. actinomycetemcomitans, but did not suppress the response induced by TNF-α. The transfection of TLR4 inhibited A. actinomycetemcomitans-induced increases in IL-8 and IL-6 mRNA levels. Confocal microscopy revealed that MβCD inhibited the mobilization of TLR4 into lipid rafts. Conclusion: The mobilization of TLR4 into lipid rafts is involved in the expression of inflammatory cytokines and phosphorylation of MAP kinase in human gingival epithelial cells stimulated by A. actinomycetemcomitans.

scholarly journals Integrated analysis of directly captured microRNA targets reveals the impact of microRNAs on mammalian transcriptome

2019 ◽  
Author(s):  
Glen A. Bjerke ◽  
Rui Yi
Keyword(s):  
Epithelial Cells ◽  
Global Analysis ◽  
Integrated Analysis ◽  
Mrna Levels ◽  
Mrna Targets ◽  
Cancer Cell Adhesion ◽  
Bona Fide ◽  
Highly Correlated ◽  
The Impact ◽  
Mammalian Transcriptome

AbstractMicroRNA (miRNA)-mediated regulation is widespread, relatively mild but functionally important. Despite extensive efforts to identify miRNA targets, it remains unclear how miRNAs bind to mRNA targets globally and how changes in miRNA levels affects the transcriptome. Here we apply an optimized method for simultaneously capturing miRNA and targeted RNA sites to wildtype, miRNA knockout and induced epithelial cells. We find that abundantly expressed miRNAs can bind to thousands of different transcripts and many different miRNAs can regulate the same gene. Although mRNA sites that are bound by miRNAs and also contain matches to seed sequences confer the strongest regulation, ∼50% of miRNAs bind to RNA regions without seed matches. In general, these bindings have little impact on mRNA levels and reflect a scanning activity of miRNAs. In addition, different miRNAs have different preferences to seed matches and 3’end base-pairing. For a single miRNA, the effectiveness of mRNA regulation is highly correlated with the number of captured miRNA:RNA fragments. Notably, elevated miRNA expression effectively represses existing targets with little impact on newly recognized targets. Global analysis of directly captured mRNA targets reveals pathways that are involved in cancer, cell adhesion and signaling pathways are highly regulated by many different miRNAs in epithelial cells. Comparison between experimentally captured and TargetScan predicted targets indicates that our approach is more effective to identify bona fide targets by reducing false positive and negative predictions. This study reveals the global binding landscape and impact of miRNAs on mammalian transcriptome.

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