首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.

Objectives

Vascular calcification is highly prevalent in patients with chronic kidney disease (CKD) and contributes to increased risk of cardiovascular disease and mortality. Accumulated evidences suggested that vascular smooth muscle cells (VSMCs) to osteoblast-like cells transdifferentiation (VOT) plays a crucial role in promoting vascular calcification. MicroRNAs (miRNAs) are a novel class of small RNAs that negatively regulate gene expression via repression of the target mRNAs. In the present work, we sought to determine the role of miRNAs in VSMCs phenotypic transition and calcification induced by β-glycerophosphoric acid.

Approach and results

Primary cultured rat aortic VSMCs were treated with β-glycerophosphoric acid for different periods of time. In VSMCs, after β-glycerophosphoric acid treatment, the expressions of cbf β1, osteocalcin and osteopontin were significantly increased and SM-22β expression was decreased. ALP activity was induced by β-glycerophosphoric acid in a time or dose dependent manner. Calcium deposition was detected in VSMCs incubated with calcification media; then, miR-125b expression was detected by real-time RT PCR. miR-125b expression was significantly decreased in VSMCs after incubated with β-glycerophosphoric acid. Overexpression of miR-125b could inhibit β-glycerophosphoric acid-induced osteogenic markers expression and calcification of VSMCs whereas knockdown of miR-125b promoted the phenotypic transition of VSMCs and calcification. Moreover, miR-125b targeted Ets1 and regulated its protein expression in VSMCs. Downregulating Ets1 expression by its siRNA inhibited β-glycerophosphoric acid-induced the VSMCs phenotypic transition and calcification.

Conclusion

Our study suggests that down-regulation of miR-125b after β-glycerophosphoric acid treatment facilitates VSMCs transdifferentiation and calcification through targeting Ets1.  相似文献   

2.
Previous study found the variable miR-3202 as a potential biomarker in smoker with or without chronic obstructive pulmonary disease (COPD). This study aims to identify the molecular involvement of miR-3202 in the pathophysiology of COPD. Level of miR-3202 in blood sample of non-smoker non-COPD(C), smoker without COPD(S), smoker with stable COPD(S-COPD) and smoker with acute exacerbation COPD(AE-COPD) was observed by quantitative real-time PCR. By bioinformatics prediction, Fas apoptotic inhibitory molecule 2 (FAIM2) was identified as a potential target of miR-3202. In vitro, human bronchial epithelial (HBE) cells and cigarette smoke extract (CSE) stimulated T lymphocytes were co-cultured. Cell proliferation and apoptosis of HBE cells were determinated. In vivo, rats were exposed in cigarette smoke for 30 days and expression of miR-3202 and FAIM2 in bronchia were detected. Results showed that The miR-3202 was down-regulated in S, S-COPD and AE-COPD group when compared with C group. Decreased level of miR-3202 was also observed in CSE treated T lymphocyte. Additionally, CSE stimulation increased INF-γ and TNF-α levels and FAIM2 expression whereas inhibited Fas and FasL expressions in T lymphocytes. However, these effects were significantly suppressed by miR-3202 overexpression and enhanced by miR-3202 inhibitor. Likely to exogenous miR-3202, FAIM2 knockdown significantly inhibited HBE cells apoptosis, as well as inhibited INF-γ and TNF-α levels. In COPD rats model, miR-3202 was reduced while FAIM2 was up-regulated accordingly. Here, results suggest that high level miR-3202 in T lymphocytes may protect epithelial cells through targeting FAIM2. MiR-3202 might be used as a notable biomarker of COPD.  相似文献   

3.
Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. This study is the first report which demonstrates the cartilage protective effect of 5,7,3′,4′-tetramethoxyflavone (TMF) by decreasing the concentration of IL-1β, TNF-α and PGE2 in the knee synovial fluid in OA rat models in vivo. In vitro, after induced by PGE2, the apoptosis rate of chondrocytes was significantly increased. In addition, PGE2 increased the expression of cAMP/PKA signaling pathway in chondrocytes, stabilized and accumulated β-catenin, and activated the expression of β-catenin signaling pathway. These activities were counteracted by TMF dose-dependently. Collectively, TMF is a potential compound with chondroprotective activity by inhibiting both EP/cAMP/PKA signaling pathway and β-catenin signaling pathway.  相似文献   

4.
The objective of this study was to determine the effects of in vitro embryo production on physical development and levels of expression of mRNAs for insulin-like growth factor (IGF) ligands (IGF1, IGF2), their receptors (IGF1R, IGF2R), and IGF binding protein-2 (IGFBP2) in bovine fetuses during early gestation. In vivo embryos were recovered from superovulated Holstein cows. For production of embryos in vitro, Holstein oocytes were matured, fertilized, and subsequently cultured in M199 with 10% serum to 168 hpi. On Day 70 of gestation, fetuses (in vivo, n = 14; in vitro, n = 13) were recovered, serum samples collected, and physical measurements recorded. Semi-quantitative RT-PCR assays were used to determine the levels of expression of mRNAs for IGF1, IGF2, IGF1R, and IGF2R in fetal liver and skeletal muscle. Western blots were used to assess levels of IGFBP2 in fetal serum. Fetal body weight did not differ with treatment; however, production of embryos in vitro was associated with decreased crown-nose length and a tendency for increased paired kidney weight, which became significant when expressed on a per bodyweight basis. There was no effect of treatment on levels of IGFBP2 in fetal serum. Levels of IGF1 mRNA in fetal liver were decreased (P < 0.001) in the in vitro group. Levels of IGF2R mRNA in both liver and skeletal muscle were also decreased (P < 0.01) in fetuses from the in vitro group. In summary, fetuses at Day 70 of gestation from embryos produced in vitro had shortened crown-nose length and increased kidney weight on a per bodyweight basis, as well as decreased expression of mRNAs for IGF1 in liver and IGF2R in both liver and skeletal muscle, compared with fetuses from embryos produced in vivo. In conclusion, in vitro embryo culture was associated with subtle changes in fetal development as well as altered expression of both imprinted and non-imprinted genes.  相似文献   

5.
Implantation failure is a major problem in human assisted reproduction, which persists regardless the optimization of endometrial receptivity and selection of genetically and morphologically healthy embryos. Since embryo-endometrium interaction depends on cell junctional, cell adhesion and cell-substratum adhesion molecules, the present study inquired whether in vitro growing murine embryos display similar to the in vivo growing embryos patterns of adhesion molecules. To this extend aVb3 expression and distribution in zygotes and 2-cell stage embryos were studied. The results demonstrated that only the in vivo growing embryos displayed specifically polarized aVb3 distribution, indicating their potential successful interaction with endometrium. Based on previous studies showing that L-carnitine (L-Cn) could affect embryonic development, it was demonstrated that the addition of L-Cn to the culture medium, could lead the in vitro growing embryos to acquire aVb3 expression and distribution similar to the in vivo growing embryos. Visualization of the effect of L-Cn using third harmonic generation imaging showed decreased lipid droplet levels in 2-cell-stage embryos, observation that correlates with an active energetic state of the growing embryos. Thus, the application of L-Cn to the culture medium could assist pre-implantation-state embryos to acquire aVb3 expression and distribution similar to the in vivo developing conditions.  相似文献   

6.
Targeting the tumor vasculature and selectively modifying endothelial functions is an attractive anti-tumor strategy. We prepared polyethyleneglycol modified immunoliposomes (IL) directed against vascular cell adhesion molecule 1 (VCAM-1), a surface receptor over-expressed on tumor vessels, and investigated the liposomal targetability in vitro and in vivo. In vitro, anti-VCAM-1 liposomes displayed specific binding to activated endothelial cells under static conditions, as well as under simulated blood flow conditions. The in vivo targeting of IL was analysed in mice bearing human Colo 677 tumor xenografts 30 min and 24 h post i.v. injection. Whereas biodistribution studies using [3H]-labelled liposomes displayed only marginal higher tumor accumulation of VCAM-1 targeted versus unspecific ILs, fluorescence microscopy evaluation revealed that their localisations within tumors differed strongly. VCAM-1 targeted ILs accumulated in tumor vessels with increasing intensities from 30 min to 24 h, while control ILs accumulated in the tumor tissue by passive diffusion. ILs that accumulated in non-affected organs, mainly liver and spleen, primarily co-localised with macrophages. This is the first morphological evidence for selective in vivo targeting of tumor vessels using ILs. VCAM-directed ILs are candidate drug delivery systems for therapeutic anti-cancer approaches designed to alter endothelial function.  相似文献   

7.
《Gene》2014,538(2):342-347
Chemotherapy plays a crucial role in hepatocellular carcinoma (HCC) treatment especially for patients with advanced HCC. Cisplatin is one of the commonly used chemotherapeutic drugs for the treatment of HCC. However, acquisition of cisplatin resistance is common in patients with HCC, and the underlying mechanism of such resistance is not fully understood. In the study, we focused on identifying the role of miRNAs in chemotherapy resistance after cisplatin-based combination chemotherapy. We assayed the expression level of miR-182 after cisplatin-based chemotherapy in patients with advanced HCC, and defined the biological functions by real-time PCR analysis and CCK-8 assay. We found that miR-182 levels were significantly increased in HCC patients treated with cisplatin-based chemotherapy. miR-182 levels were also higher in cisplatin-resistant HepG2 (HepG2-R) cells than in HepG2 cells. Upregulated miR-182 significantly increased the cell viability, whereas miR-182 knockdown reduced the cell viability during cisplatin treatment. miR-182 inhibition also partially overcame cisplatin resistance in HepG2-R cell. Furthermore, we found that upregulated miR-182 inhibited the expression of tumor suppressor gene TP53INP1 (tumor protein 53-induced nuclear protein1) in vitro. In vivo, miR-182 and TP53INP1 expression was negatively correlated. We finally demonstrated that miR-182 increased cisplatin resistance of HCC cell, partly by targeting TP53INP1. These data suggest that miR-182/TP53INP1 signaling represents a novel pathway regulating chemoresistance, thus offering a new target for chemotherapy of HCC.  相似文献   

8.
Human growth hormone (hGH) plays critical roles in pubertal mammary gland growth, development, and sexual maturation. Accumulated studies have reported that autocrine/paracrine hGH is an orthotopically expressed oncoprotein that promotes normal mammary epithelial cell oncogenic transformation. Autocrine/paracrine hGH has also been reported to promote mammary epithelial cell epithelial-mesenchymal transition (EMT) and invasion. However, the underlying mechanism remains largely obscure. MicroRNAs (miRNAs) are reported to be involved in regulation of multiple cellular functions of cancer. To determine whether autocrine/paracrine hGH promotes EMT and invasion through modulation of miRNA expression, we performed microarray profiling using MCF-7 cells stably expressing wild type or a translation-deficient hGH gene and identified miR-96-182-183 as an autocrine/paracrine hGH-regulated miRNA cluster. Forced expression of miR-96-182-183 conferred on epithelioid MCF-7 cells a mesenchymal phenotype and promoted invasive behavior in vitro and dissemination in vivo. Moreover, we observed that miR-96-182-183 promoted EMT and invasion by directly and simultaneously suppressing BRMS1L (breast cancer metastasis suppressor 1-like) gene expression. miR-96 and miR-182 also targeted GHR, providing a potential negative feedback loop in the hGH-GHR signaling pathway. We further demonstrated that autocrine/paracrine hGH stimulated miR-96-182-183 expression and facilitated EMT and invasion via STAT3 and STAT5 signaling. Consistent with elevated expression of autocrine/paracrine hGH in metastatic breast cancer tissue, miR-96-182-183 expression was also remarkably enhanced. Hence, we delineate the roles of the miRNA-96-182-183 cluster and elucidate a novel hGH-GHR-STAT3/STAT5-miR-96-182-183-BRMS1L-ZEB1/E47-EMT/invasion axis, which provides further understanding of the mechanism of autocrine/paracrine hGH-stimulated EMT and invasion in breast cancer.  相似文献   

9.
Perisynaptic astrocytes express important glutamate transporters, especially excitatory amino acid transporter 2 (EAAT2, rodent analog GLT1) to regulate extracellular glutamate levels and modulate synaptic activation. In this study, we investigated an exciting new pathway, the exosome-mediated transfer of microRNA (in particular, miR-124a), in neuron-to-astrocyte signaling. Exosomes isolated from neuron-conditioned medium contain abundant microRNAs and small RNAs. These exosomes can be directly internalized into astrocytes and increase astrocyte miR-124a and GLT1 protein levels. Direct miR-124a transfection also significantly and selectively increases protein (but not mRNA) expression levels of GLT1 in cultured astrocytes. Consistent with our in vitro findings, intrastriatal injection of specific antisense against miR-124a into adult mice dramatically reduces GLT1 protein expression and glutamate uptake levels in striatum without reducing GLT1 mRNA levels. MiR-124a-mediated regulation of GLT1 expression appears to be indirect and is not mediated by its suppression of the putative GLT1 inhibitory ligand ephrinA3. Moreover, miR-124a is selectively reduced in the spinal cord tissue of end-stage SOD1 G93A mice, the mouse model of ALS. Subsequent exogenous delivery of miR-124a in vivo through stereotaxic injection significantly prevents further pathological loss of GLT1 proteins, as determined by GLT1 immunoreactivity in SOD1 G93A mice. Together, our study characterized a new neuron-to-astrocyte communication pathway and identified miRNAs that modulate GLT1 protein expression in astrocytes in vitro and in vivo.  相似文献   

10.
11.
Sortilin is a post-Golgi trafficking receptor homologous to the yeast vacuolar protein sorting receptor 10 (VPS10). The VPS10 motif on sortilin is a 10-bladed β-propeller structure capable of binding more than 50 proteins, covering a wide range of biological functions including lipid and lipoprotein metabolism, neuronal growth and death, inflammation, and lysosomal degradation. Sortilin has a complex cellular trafficking itinerary, where it functions as a receptor in the trans-Golgi network, endosomes, secretory vesicles, multivesicular bodies, and at the cell surface. In addition, sortilin is associated with hypercholesterolemia, Alzheimer’s disease, prion diseases, Parkinson’s disease, and inflammation syndromes. The 1p13.3 locus containing SORT1, the gene encoding sortilin, carries the strongest association with LDL-C of all loci in human genome-wide association studies. However, the mechanism by which sortilin influences LDL-C is unclear. Here, we review the role sortilin plays in cardiovascular and metabolic diseases and describe in detail the large and often contradictory literature on the role of sortilin in the regulation of LDL-C levels.  相似文献   

12.
13.
Elevated plasma lipoprotein(a) (Lp(a)) is an independent, causal risk factor for atherosclerotic cardiovascular disease and calcific aortic valve stenosis. Lp(a) is formed in or on hepatocytes from successive noncovalent and covalent interactions between apo(a) and apoB, although the subcellular location of these interactions and the nature of the apoB-containing particle involved remain unclear. Sortilin, encoded by the SORT1 gene, modulates apoB secretion and LDL clearance. We used a HepG2 cell model to study the secretion kinetics of apo(a) and apoB. Overexpression of sortilin increased apo(a) secretion, while siRNA-mediated knockdown of sortilin expression correspondingly decreased apo(a) secretion. Sortilin binds LDL but not apo(a) or Lp(a), indicating that its effect on apo(a) secretion is likely indirect. Indeed, the effect was dependent on the ability of apo(a) to interact noncovalently with apoB. Overexpression of sortilin enhanced internalization of Lp(a), but not apo(a), by HepG2 cells, although neither sortilin knockdown in these cells or Sort1 deficiency in mice impacted Lp(a) uptake. We found several missense mutations in SORT1 in patients with extremely high Lp(a) levels; sortilin containing some of these mutations was more effective at promoting apo(a) secretion than WT sortilin, though no differences were found with respect to Lp(a) internalization. Our observations suggest that sortilin could play a role in determining plasma Lp(a) levels and corroborate in vivo human kinetic studies which imply that secretion of apo(a) and apoB are coupled, likely within the hepatocyte.  相似文献   

14.
The G protein-coupled receptor 119 (GPR119) is highly expressed in pancreatic β-cells. On activation, this receptor enhances the effect of glucose-stimulated insulin secretion (GSIS) via the elevation of intracellular cAMP concentrations. Although GPR119 agonists represent promising oral antidiabetic agents for the treatment of type 2 diabetes therapy, they suffer from the inability to adequately directly preserve β-cell function. To identify a new structural class of small-molecule GPR119 agonists with both GSIS and the potential to preserve β-cell function, we screened a library of synthetic compounds and identified a candidate molecule, AS1269574, with a 2,4,6-tri-substituted pyrimidine core. Here, we examined the preliminary in vitro and in vivo effects of AS1269574 on insulin secretion and glucose tolerance. AS1269574 had an EC50 value of 2.5 μM in HEK293 cells transiently expressing human GPR119 and enhanced insulin secretion in the mouse pancreatic β-cell line MIN-6 only under high-glucose (16.8 mM) conditions. This contrasted with the action of the sulfonylurea glibenclamide, which also induced insulin secretion under low-glucose conditions (2.8 mM). In in vivo studies, a single administration of AS1269574 to normal mice reduced blood glucose levels after oral glucose loading based on the observed insulin secretion profiles. Significantly, AS1269574 did not affect fed and fasting plasma glucose levels in normal mice. Taken together, these results suggest that AS1269574 represents a novel structural class of small molecule, orally administrable GPR119 agonists with GSIS and promising potential for the treatment of type 2 diabetes.  相似文献   

15.
16.
17.
Membrane-integrated nitric oxide reductase (NOR) reduces nitric oxide (NO) to nitrous oxide (N2O) with protons and electrons. This process is essential for the elimination of the cytotoxic NO that is produced from nitrite (NO2?) during microbial denitrification. A structure-guided mutagenesis of NOR is required to elucidate the mechanism for NOR-catalyzed NO reduction. We have already solved the crystal structure of cytochrome c-dependent NOR (cNOR) from Pseudomonas aeruginosa. In this study, we then constructed its expression system using cNOR-gene deficient and wild-type strains for further functional study. Characterizing the variants of the five conserved Glu residues located around the heme/non-heme iron active center allowed us to establish how the anaerobic growth rate of cNOR-deficient strains expressing cNOR variants correlates with the in vitro enzymatic activity of the variants. Since bacterial strains require active cNOR to eliminate cytotoxic NO and to survive under denitrification conditions, the anaerobic growth rate of a strain with a cNOR variant is a good indicator of NO decomposition capability of the variants and a marker for the screening of functionally important residues without protein purification. Using this in vivo screening system, we examined the residues lining the putative proton transfer pathways for NO reduction in cNOR, and found that the catalytic protons are likely transferred through the Glu57 located at the periplasmic protein surface. The homologous cNOR expression system developed here is an invaluable tool for facile identification of crucial residues in vivo, and for further in vitro functional and structural studies.  相似文献   

18.
In the present study, using an in vivo approach (a microdialysis technique associated to HPLC with fluorimetric detection) and in vitro purified hippocampal synaptosomes in superfusion, we investigated the glycinergic transmission in the hippocampus, focusing on the nicotinic control of glycine (GLY) release. The acute administration of nicotine in vivo was able to evoke endogenous GLY release in the rat hippocampus. The specific nicotinic agonists PHA-543613 hydrochloride (PHA543613) selective for the α7 nicotinic receptor subtype administered in vivo also elicited GLY release in a similar extent, while the α4β2 agonist 5-IA85380 dihydrochloride (5IA85380) was less effective. Nicotine elicited GLY overflow also from hippocampal synaptosomes in vitro. This overflow was Ca2+-dependent and inhibited by methyllycaconitine (MLA), but was not modified by dihydro-beta-erythroidine (DHβE, 1 μM). Choline(Ch)-evoked GLY overflow was Ca2+ dependent, unaltered in presence of DHβE and blocked by methyllycaconitine (MLA). Additionally, 5IA85380 elicited a GLY overflow, which in turn was Ca2+ dependent, was significantly inhibited by DHβE but was unaffected by MLA. The GLY overflow produced by these nicotinic agonists quantitatively resembles that evoked by 9 mM KCl. The effects of a high concentration of 5IA85380 (1 mM), in the presence of 2 μM DHβE, on the release of GLY was also studied comparatively to that on glutamate and aspartate release. The nicotinic agonist 5IA85380 tested at high concentration (1 mM) was able to produce a stimulatory effect of endogenous release of the three amino acids, even in the presence of 2 μM DHβE, indicating the existence of a DHβE resistant, α4β2 nAChR subtype with a functional role in the modulation of GLY, ASP, and GLU release. Our results show that in the rat hippocampus the release of GLY is, at least in part, of neuronal origin and is modulated by the activation of both α7 and α4β2 (low and high affinity) nAChR subtypes.  相似文献   

19.
Lysophosphatidic acid (LPA) is a pro-fibrotic mediator acting via specific receptors (LPARs) and is synthesized by autotaxin, that increases with obesity. We tested whether LPA could play a role in adipose tissue (AT)-fibrosis associated with obesity. Fibrosis [type I, III, and IV collagens (COL), fibronectin (FN), TGFβ, CTGF and αSMA] and inflammation (MCP1 and F4/80) markers were quantified: (i) in vivo in inguinal (IAT) and perigonadic (PGAT) AT from obese-diabetic db/db mice treated with the LPAR antagonist Ki16425 (5 mg/kg/day ip for 7 weeks); and (ii) in vitro in human AT explants in primary culture for 72 h in the presence of oleoyl-LPA (10 μM) and/or Ki16425 (10 μM) and/or the HIF-1α inhibitor YC-1 (100 μM). Treatment of db/db mice with Ki16425 reduced Col I and IV mRNAs in IAT and PGAT while Col III mRNAs were only reduced in IAT. This was associated with reduction of COL protein staining in both IAT and PGAT. AT explants showed a spontaneous and time-dependent increase in ATX expression and production of LPA in the culture medium, along with increased levels of Col I and III, TGFβ and αSMA mRNAs and of COL protein staining. In vitro fibrosis was blocked by Ki16425 and was further amplified by oleoyl-LPA. LPA-dependent in vitro fibrosis was blocked by co-treatment with YC1. Our results show that endogenous and exogenous LPA exert a pro-fibrotic activity in AT in vivo and in vitro. This activity could be mediated by an LPA1R-dependent pathway and could involve HIF-1α.  相似文献   

20.

Background

Traditional antibacterial photocatalysts are primarily induced by ultraviolet light to elicit antibacterial reactive oxygen species. New generation visible-light responsive photocatalysts were discovered, offering greater opportunity to use photocatalysts as disinfectants in our living environment. Recently, we found that visible-light responsive platinum-containing titania (TiO2–Pt) exerted high performance antibacterial property against soil-borne pathogens even in soil highly contaminated water. However, its physical and photocatalytic properties, and the application in vivo have not been well-characterized.

Methods

Transmission electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, ultraviolet–visible absorption spectrum and the removal rate of nitrogen oxides were therefore analyzed. The antibacterial performance under in vitro and in vivo conditions was evaluated.

Results

The apparent quantum efficiency for visible light illuminated TiO2–Pt is relatively higher than several other titania photocatalysts. The killing effect achieved approximately 2 log reductions of pathogenic bacteria in vitro. Illumination of injected TiO2–Pt successfully ameliorated the subcutaneous infection in mice.

Conclusions

This is the first demonstration of in vivo antibacterial use of TiO2–Pt nanoparticles. When compared to nanoparticles of some other visible-light responsive photocatalysts, TiO2–Pt nanoparticles induced less adverse effects such as exacerbated platelet clearance and hepatic cytotoxicity in vivo.

General significance

These findings suggest that the TiO2–Pt may have potential application on the development of an antibacterial material in both in vitro and in vivo settings.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号