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Sample records for mir-143 regulate smooth

  1. MiR-143-3p controls TGF-β1-induced cell proliferation and extracellular matrix production in airway smooth muscle via negative regulation of the nuclear factor of activated T cells 1.

    PubMed

    Cheng, Wei; Yan, Kun; Xie, Li-Yi; Chen, Feng; Yu, Hong-Chuan; Huang, Yan-Xia; Dang, Cheng-Xue

    2016-10-01

    MicroRNAs (miRNAs) are small noncoding RNAs that function in diverse biological processes. However, little is known about the precise role of microRNAs in the functioning of airway smooth muscle cells (ASMCs). Here, we investigated the potential role and mechanisms of the miR-143 -3p on proliferation and the extracellular matrix (ECM) protein production of ASMCs. We demonstrated that miR-143-3p was aberrantly lower in ASMCs isolated from individuals with asthma than in individuals without asthma. Meanwhile, TGF-β1 caused a marked decrease in a time-dependent manner in miR-143-3p expression in ASMCs from asthmatics. Additionally, the overexpression of miR- 143-3p robustly reduced TGF-β1-induced ASMCs proliferation and downregulated CDK and cyclin expression, whereas the inhibition of miR-143-3p significantly enhanced ASMCs proliferation and upregulated the level of CDKs and cyclins. Re-expression of miR-143-3p attenuated ECM protein deposition reflected as a marked decrease in the expression of type I collagen and fibronectin, whereas miR-143-3p downregulation caused an opposite effect on the expression of type I collagen and fibronectin. Moreover, qRT-PCR and western blot analysis indicated that miR-143-3p negatively regulated the expression of nuclear factor of activated T cells 1 (NFATc1). Subsequent analyses demonstrated that NFATc1 was a direct and functional target of miR-143-3p, which was validated by the dual luciferase reporter assay. Most importantly, the overexpression of NFATc1 effectively reversed the inhibition of miR-143-3p on TGF-β1-induced proliferation, and strikingly abrogated the effect of miR-143-3p on the expression of CDK4 and Cyclin D1. Together, miR-143-3p may function as an inhibitor of asthma airway remodeling by suppressing proliferation and ECM protein deposition in TGF-β1-mediated ASMCs via the negative regulation of NFATc1 signaling, suggesting miR-143-3p as a potential therapeutic target for asthma.

  2. miR-143 regulates proliferation and differentiation of bovine skeletal muscle satellite cells by targeting IGFBP5.

    PubMed

    Zhang, Wei Ran; Zhang, Hui Na; Wang, Yi Min; Dai, Yang; Liu, Xin Feng; Li, Xin; Ding, Xiang Bin; Guo, Hong

    2017-03-01

    Development of skeletal muscle is a complicated biological process regulated by various regulation factors and signal pathways. MicroRNAs (miRNAs) are novel gene regulators that control muscle cell development. microRNA-143 (miR-143) is highly expressed in skeletal muscle, and we found that miR-143 level is significantly increased during bovine skeletal muscle satellite cells (MSCs) differentiation process through microarray analysis and qRT-PCR detection. However, the function of miR-143 in bovine muscle development remained unclear. In our work, the functions of miR-143 in bovine MSCs myogenic differentiation were investigated. We discovered that IGFBP5 is directly regulated by miR-143 using a dual-luciferase reporter assay. Overexpression of miR-143 led to decreased level of IGFBP5 protein and restrained cell proliferation and differentiation, while downregulation of miR-143 resulted in increased levels of IGFBP5 protein and restrained cell proliferation but improved differentiation. IGFBP5, an important component of IGF signaling pathway, contributes greatly to bovine muscle cell development. A mechanism that miR-143 can regulate the proliferation and differentiation of bovine MSCs through changing expression of IGFBP5 was elucidated by our study.

  3. MiR-143 and MiR-145 Regulate IGF1R to Suppress Cell Proliferation in Colorectal Cancer

    PubMed Central

    Wang, Nan; Zhang, Suyang; Yan, Xin; Feng, Hui; Pang, Wenjing; Wang, Yanbo; Wang, Xueliang; Fu, Zhen; Liu, Yanqing; Zhao, Chihao; Zhang, Junfeng; Zhang, Chen-Yu; Zen, Ke; Chen, Xi; Wang, Yalei

    2014-01-01

    Insulin-like growth factor 1 receptor (IGF1R) is a transmembrane receptor that is activated by insulin-like growth factor 1 (IGF-1) and by a related hormone called IGF-2. It belongs to the large class of tyrosine kinase receptors and plays an important role in colorectal cancer etiology and progression. In this study, we used bioinformatic analyses to search for miRNAs that potentially target IGF1R. We identified specific target sites for miR-143 and miR-145 (miR-143/145) in the 3′-untranslated region (3′-UTR) of the IGF1R gene. These miRNAs are members of a cluster of miRNAs that have been reported to exhibit tumor suppressor activity. Consistent with the bioinformatic analyses, we identified an inverse correlation between miR-143/145 levels and IGF1R protein levels in colorectal cancer tissues. By overexpressing miR-143/145 in Caco2, HT29 and SW480 colorectal cancer cells, we experimentally validated that miR-143/145 directly recognizes the 3′-UTR of the IGF1R transcript and regulates IGF1R expression. Furthermore, the biological consequences of the targeting of IGF1R by miR-143/145 were examined by cell proliferation assays in vitro. We demonstrated that the repression of IGF1R by miR-143/145 suppressed the proliferation of Caco2 cells. Taken together, our findings provide evidence for a role of the miR-143/145 cluster as a tumor suppressor in colorectal cancer through the inhibition of IGF1R translation. PMID:25474488

  4. Cholesterol loading re-programs the miR-143/145-myocardin axis to convert aortic smooth muscle cells to a dysfunctional macrophage-like phenotype

    PubMed Central

    Vengrenyuk, Yuliya; Nishi, Hitoo; Long, Xiaochun; Ouimet, Mireille; Savji, Nazir; Martinez, Fernando O.; Cassella, Courtney P.; Moore, Kathryn J.; Ramsey, Stephen A.; Miano, Joseph M.; Fisher, Edward A.

    2015-01-01

    Objective We previously showed that cholesterol loading in vitro converts mouse aortic vascular smooth muscle cells (VSMC) from a contractile state to one resembling macrophages. In human and mouse atherosclerotic plaques it has become appreciated that ~40% of cells classified as macrophages by histological markers may be of VSMC origin. We therefore sought to gain insight into the molecular regulation of this clinically relevant process. Approach and Results VSMC of mouse (or human) origin were incubated with cyclodextrin-cholesterol complexes for 72 hours, at which time the expression at the protein and mRNA levels of contractile-related proteins were reduced and of macrophage markers increased. Concurrent was down regulation of miR-143/145, which positively regulate the master VSMC-differentiation transcription factor myocardin (MYOCD). Mechanisms were further probed in mouse VSMC. Maintaining the expression of MYOCD or miR-143/145 prevented and reversed phenotypic changes caused by cholesterol loading. Reversal was also seen when cholesterol efflux was stimulated after loading. Notably, despite expression of macrophage markers, bioinformatic analyses showed that cholesterol-loaded cells remained closer to the VSMC state, consistent with impairment in classical macrophage functions of phagocytosis and efferocytosis. In apoE-deficient atherosclerotic plaques, cells positive for VSMC and macrophage markers were found lining the cholesterol-rich necrotic core. Conclusions Cholesterol loading of VSMC converts them to a macrophage–appearing state by downregulating the miR-143/145-myocardin axis. Though these cells would be classified by immunohistochemistry as macrophages in human and mouse plaques, their transcriptome and functional properties imply that their contributions to atherogenesis would not be those of classical macrophages. PMID:25573853

  5. [miR-143 inhibits cell proliferation through targeted regulating the expression of K-ras gene in HeLa cells].

    PubMed

    Qin, H X; Cui, H K; Pan, Y; Hu, R L; Zhu, L H; Wang, S J

    2016-12-23

    Objective: To explore the effect of microRNA miR-143 on the proliferation of cervical cancer HeLa cells through targeted regulating the expression of K-ras gene. Methods: The luciferase report carrier containing wild type 3'-UTR of K-ras gene (K-ras-wt) or mutated 3'-UTR of the K-ras (K-ras-mut) were co-transfected with iR-143 mimic into the HeLa cells respectively, and the targeting effect of miR-143 in the transfectants was verified by the dual luciferase report system. HeLa cells were also transfected with miR-143 mimic (miR-143 mimic group), mimic control (negative control group), and miR-143 mimic plus K-ras gene (miR-143 mimic+ K-ras group), respectively. The expression of miR-143 in the transfected HeLa cells was detected by real-time PCR (RT-PCR), and the expression of K-ras protein was detected by Western blot. The cell proliferation activity of each group was examined by MTT assay. In addition, human cervical cancer tissue samples (n=5) and cervical intraepithelial neoplasia tissue samples (n=5) were also examined for the expression of miR-143 and K-ras protein by RT-PCR and Western blot, respectively. Results: The luciferase report assay showed that co-transfection with miR-143 mimic decreased the luciferase activity of the K-ras-wt significantly, but did not inhibit the luciferase activity of the K-ras-mut. The expression of miR-143 in the HeLa cells transfected with miR-143 mimic was significantly higher than that in the HeLa cells transfected with the mimic control (3.31±0.45 vs 0.97±0.22, P<0.05). The MTT assay revealed that the cell proliferative activity of the miR-143 mimic group was significantly lower than that of the negative control group (P<0.05), and the cell proliferative activity of the miR-143 mimic+ K-ras group was also significantly lower than the control group (P<0.05) but higher than the miR-143 mimic group significantly (P<0.05). The expression levels of K-ras protein in the miR-143 mimic group, the negative control group and the

  6. DDX6 post-transcriptionally down-regulates miR-143/145 expression through host gene NCR143/145 in cancer cells.

    PubMed

    Iio, Akio; Takagi, Takeshi; Miki, Kohei; Naoe, Tomoki; Nakayama, Atsuo; Akao, Yukihiro

    2013-10-01

    In various human malignancies, widespread dysregulation of microRNA (miRNA) expression is reported to occur and affects various cell growth programs. Recent studies suggest that the expression levels of miRNAs that act as tumor suppressors are frequently reduced in cancers because of chromosome deletions, epigenetical changes, aberrant transcription, and disturbances in miRNA processing. MiR-143 and -145 are well-recognized miRNAs that are highly expressed in several tissues, but down-regulated in most types of cancers. However, the mechanism of this down-regulation has not been investigated in detail. Here, we show that DEAD-box RNA helicase 6, DDX6 (p54/RCK), post-transcriptionally down-regulated miR-143/145 expression by prompting the degradation of its host gene product, NCR143/145 RNA. In human gastric cancer cell line MKN45, DDX6 protein was abundantly expressed and accumulated in processing bodies (P-bodies). DDX6 preferentially increased the instability of non-coding RNA, NCR143/145, which encompasses the miR-143/145 cluster, and down-regulated the expression of mature miR-143/145. In human monocytic cell line THP-1, lipopolysaccharide treatment promoted the assembly of P-bodies and down-regulated the expression of NCR143/145 and its miR-143/145 rapidly. In these cells, cycloheximide treatment led to a loss of P-bodies and to an increase in NCR143/145 RNA stability, thus resulting in up-regulation of miR-143/145 expression. These data demonstrate that DDX6 contributed to the control of NCR143/145 RNA stability in P-bodies and post-transcriptionally regulated miR-143/145 expression in cancer cells.

  7. The Cluster of miR-143 and miR-145 Affects the Risk for Esophageal Squamous Cell Carcinoma through Co-Regulating Fascin Homolog 1

    PubMed Central

    Liu, Ran; Liao, Juan; Yang, Miao; Sheng, Jingyi; Yang, Hao; Wang, Yi; Pan, Enchun; Guo, Wei; Pu, Yuepu; Kim, Sun Jung; Yin, Lihong

    2012-01-01

    MicroRNAs (miRNAs), 18–24 nt non-coding RNAs, are thought to play important roles in cell proliferation, differentiation, apoptosis, and development. Recent studies suggest that some of the known microRNAs map to a single genomic locale within a single polycistronic transcript. But the roles of the cluster remain to be known. In order to understand the role and mechanism of a cluster of miR-143 and miR-145 in esophageal squamous cell carcinoma (ESCC), the association of mature miR-143 and miR-145 expression with the risk for esophageal cancer was evaluated in ESCC patients with a case-control study, and target protein regulated by mature miRNA was analyzed in ESCC cell lines with 3′UTR luciferase reporter assay. The expression levels of miR-143 and miR-145 were determined in 110 pairs of esophageal cancer tissues and adjacent normal tissues using real-time reverse transcription PCR. The relative expression of miR-143 and miR-145 were statistically different between cancer tissues and matched controls. The combined expression of miR-143 and miR-145 was significantly associated with the risk for esophageal cancer. Meanwhile, the reduced expression of two miRNAs in tumor patient was supposed to have a trend of lymph node metastases. The co-expression pattern of miR-143 and miR-145 was analyzed with Pearson correlation. It showed a significant correlation between these two miRNAs expression both in tissues and tumor cell lines. 3′UTR luciferase reporter assay indicated that Fascin Homolog 1 (FSCN1) could be co-regulated by miR-143 and miR-145. The protein level of FSCN1 showed no significant linear correlation with miR-143 and miR-145 expression in ESCC cell lines with Western blotting analysis. In conclusion, since miR-143 and miR-145 could regulate oncogenic FSCN1 and take part in the modulation of metastases, the result suggested the combination variable of miR-143 and miR-145 as a potential biomarker for earlier diagnosis and prognosis of esophageal cancer

  8. Regulation signature of miR-143 and miR-26 in porcine Salmonella infection identified by binding site enrichment analysis.

    PubMed

    Yao, Min; Gao, Weihua; Tao, Hengxun; Yang, Jun; Liu, Guoping; Huang, Tinghua

    2016-04-01

    Salmonella infects many vertebrate species, and pigs colonized with Salmonella are typically Salmonella carriers. Transcriptomic analysis of the response to Salmonella infection in whole blood has been reported for the pig. The objective of this study is to identify the important miRNAs involved in Salmonella infection using binding site enrichment analysis. We predicted porcine microRNA (miRNA) binding sites in the 3' UTR of protein-coding genes for all miRNA families. Based on those predictions, we analyzed miRNA-binding sites for mRNAs expressed in peripheral blood to investigate the functional importance of miRNAs in Salmonella infection in pig. Enrichment analysis revealed that binding sites of five miRNAs (including miR-143, -9839, -26, -2483, and -4335) were significantly over represented for the differentially expressed gene sets. Real-time PCR results indicated that selected members of this miRNA group (miR-143, -26, and -4335) were differentially expressed in whole blood after Salmonella inoculation. The luciferase reporter assay showed that ATP6V1A and IL13RA1 were targets of miR-143 and that miR-26 regulates BINP3L and ARL6IP6. The results strongly suggest that miR-143 and miR-26 play important regulatory roles in the development of Salmonella infection in pig.

  9. RBM3 regulates temperature sensitive miR-142-5p and miR-143 (thermomiRs), which target immune genes and control fever.

    PubMed

    Wong, Justin J-L; Au, Amy Y M; Gao, Dadi; Pinello, Natalia; Kwok, Chau-To; Thoeng, Annora; Lau, Katherine A; Gordon, Jane E A; Schmitz, Ulf; Feng, Yue; Nguyen, Trung V; Middleton, Robert; Bailey, Charles G; Holst, Jeff; Rasko, John E J; Ritchie, William

    2016-04-07

    Fever is commonly used to diagnose disease and is consistently associated with increased mortality in critically ill patients. However, the molecular controls of elevated body temperature are poorly understood. We discovered that the expression of RNA-binding motif protein 3 (RBM3), known to respond to cold stress and to modulate microRNA (miRNA) expression, was reduced in 30 patients with fever, and in THP-1-derived macrophages maintained at a fever-like temperature (40 °C). Notably, RBM3 expression is reduced during fever whether or not infection is demonstrable. Reduced RBM3 expression resulted in increased expression of RBM3-targeted temperature-sensitive miRNAs, we termed thermomiRs. ThermomiRs such as miR-142-5p and miR-143 in turn target endogenous pyrogens including IL-6, IL6ST, TLR2, PGE2 and TNF to complete a negative feedback mechanism, which may be crucial to prevent pathological hyperthermia. Using normal PBMCs that were exogenously exposed to fever-like temperature (40 °C), we further demonstrate the trend by which decreased levels of RBM3 were associated with increased levels of miR-142-5p and miR-143 and vice versa over a 24 h time course. Collectively, our results indicate the existence of a negative feedback loop that regulates fever via reduced RBM3 levels and increased expression of miR-142-5p and miR-143.

  10. RBM3 regulates temperature sensitive miR-142–5p and miR-143 (thermomiRs), which target immune genes and control fever

    PubMed Central

    Wong, Justin J.-L.; Au, Amy Y.M.; Gao, Dadi; Pinello, Natalia; Kwok, Chau-To; Thoeng, Annora; Lau, Katherine A.; Gordon, Jane E.A.; Schmitz, Ulf; Feng, Yue; Nguyen, Trung V.; Middleton, Robert; Bailey, Charles G.; Holst, Jeff; Rasko, John E.J.; Ritchie, William

    2016-01-01

    Fever is commonly used to diagnose disease and is consistently associated with increased mortality in critically ill patients. However, the molecular controls of elevated body temperature are poorly understood. We discovered that the expression of RNA-binding motif protein 3 (RBM3), known to respond to cold stress and to modulate microRNA (miRNA) expression, was reduced in 30 patients with fever, and in THP-1-derived macrophages maintained at a fever-like temperature (40°C). Notably, RBM3 expression is reduced during fever whether or not infection is demonstrable. Reduced RBM3 expression resulted in increased expression of RBM3-targeted temperature-sensitive miRNAs, we termed thermomiRs. ThermomiRs such as miR-142–5p and miR-143 in turn target endogenous pyrogens including IL-6, IL6ST, TLR2, PGE2 and TNF to complete a negative feedback mechanism, which may be crucial to prevent pathological hyperthermia. Using normal PBMCs that were exogenously exposed to fever-like temperature (40°C), we further demonstrate the trend by which decreased levels of RBM3 were associated with increased levels of miR-142–5p and miR-143 and vice versa over a 24 h time course. Collectively, our results indicate the existence of a negative feedback loop that regulates fever via reduced RBM3 levels and increased expression of miR-142–5p and miR-143. PMID:26825461

  11. miR-143 Interferes with ERK5 Signaling, and Abrogates Prostate Cancer Progression in Mice

    PubMed Central

    Clapé, Cyrielle; Fritz, Vanessa; Henriquet, Corinne; Apparailly, Florence; Fernandez, Pedro Luis; Iborra, François; Avancès, Christophe; Villalba, Martin; Culine, Stéphane; Fajas, Lluis

    2009-01-01

    Background Micro RNAs are small, non-coding, single-stranded RNAs that negatively regulate gene expression at the post-transcriptional level. Since miR-143 was found to be down-regulated in prostate cancer cells, we wanted to analyze its expression in human prostate cancer, and test the ability of miR-43 to arrest prostate cancer cell growth in vitro and in vivo. Results Expression of miR-143 was analyzed in human prostate cancers by quantitative PCR, and by in situ hybridization. miR-143 was introduced in cancer cells in vivo by electroporation. Bioinformatics analysis and luciferase-based assays were used to determine miR-143 targets. We show in this study that miR-143 levels are inversely correlated with advanced stages of prostate cancer. Rescue of miR-143 expression in cancer cells results in the arrest of cell proliferation and the abrogation of tumor growth in mice. Furthermore, we show that the effects of miR-143 are mediated, at least in part by the inhibition of extracellular signal-regulated kinase-5 (ERK5) activity. We show here that ERK5 is a miR-143 target in prostate cancer. Conclusions miR-143 is as a new target for prostate cancer treatment. PMID:19855844

  12. Genetic versus Non-Genetic Regulation of miR-103, miR-143 and miR-483-3p Expression in Adipose Tissue and Their Metabolic Implications—A Twin Study

    PubMed Central

    Bork-Jensen, Jette; Thuesen, Anne Cathrine Baun; Bang-Bertelsen, Claus Heiner; Grunnet, Louise Groth; Pociot, Flemming; Beck-Nielsen, Henning; Ozanne, Susan E.; Poulsen, Pernille; Vaag, Allan

    2014-01-01

    Murine models suggest that the microRNAs miR-103 and miR-143 may play central roles in the regulation of subcutaneous adipose tissue (SAT) and development of type 2 diabetes (T2D). The microRNA miR-483-3p may reduce adipose tissue expandability and cause ectopic lipid accumulation, insulin resistance and T2D. We aimed to explore the genetic and non-genetic factors that regulate these microRNAs in human SAT, and to investigate their impact on metabolism in humans. Levels of miR-103, miR-143 and miR-483-3p were measured in SAT biopsies from 244 elderly monozygotic and dizygotic twins using real-time PCR. Heritability estimates were calculated and multiple regression analyses were performed to study associations between these microRNAs and measures of metabolism, as well as between these microRNAs and possible regulating factors. We found that increased BMI was associated with increased miR-103 expression levels. In addition, the miR-103 levels were positively associated with 2 h plasma glucose levels and hemoglobin A1c independently of BMI. Heritability estimates for all three microRNAs were low. In conclusion, the expression levels of miR-103, miR-143 and miR-483-3p in adipose tissue are primarily influenced by non-genetic factors, and miR-103 may be involved in the development of adiposity and control of glucose metabolism in humans. PMID:25010252

  13. Novel MIR143-NOTCH Fusions in Benign and Malignant Glomus Tumors

    PubMed Central

    Mosquera, Juan-Miguel; Sboner, Andrea; Zhang, Lei; Chen, Chun-Liang; Sung, Yun-Shao; Chen, Hsiao-Wei; Agaram, Narasimhan P.; Briskin, Daniel; Basha, Basma M.; Singer, Samuel; Rubin, Mark A.; Tuschl, Thomas; Antonescu, Cristina R.

    2013-01-01

    Glomus tumors (GT) have been classified among tumors of perivascular smooth muscle differentiation, together with myopericytoma, myofibroma/tosis, and angioleiomyoma, based on their morphologic overlap. However, no molecular studies have been carried out to date to investigate their genetic phenotype and to confirm their shared pathogenesis. RNA sequencing was performed in three index cases (GT1, malignant GT; GT2, benign GT and M1, multifocal myopericytoma), followed by FusionSeq data analysis, a modular computational tool developed to discover gene fusions from paired-end RNA-seq data. A gene fusion involving MIR143 in band 5q32 was identified in both GTs with either NOTCH2 in 1p13 in GT1 or NOTCH1 in 9q34 in GT2, but none in M1. After being validated by FISH and RT-PCR, these abnormalities were screened on 33 GTs, 6 myopericytomas, 9 myofibroma/toses, 18 angioleiomyomas and in a control group of 5 sino-nasal hemangiopericytomas. Overall NOTCH2 gene rearrangements were identified in 52% of GT, including all malignant cases and one NF1-related GT. No additional cases showed NOTCH1 rearrangement. As NOTCH3 shares similar functions with NOTCH2 in regulating vascular smooth muscle development, the study group was also investigated for abnormalities in this gene by FISH. Indeed, NOTCH3 rearrangements were identified in 9% of GTs, all present in benign soft tissue GT, one case being fused to MIR143. Only 1/18 angioleiomyomas showed NOTCH2 gene rearrangement, while all the myopericytomas and myofibroma/toses were negative. In summary we describe novel NOTCH1-3 rearrangements in benign and malignant, visceral and soft tissue GTs. PMID:23999936

  14. miR-143 Induces the Apoptosis of Prostate Cancer LNCap Cells by Suppressing Bcl-2 Expression

    PubMed Central

    Ma, Zhiwei; Luo, Yizhao; Qiu, Mingxing

    2017-01-01

    Background Prostate cancer has become a serious threat to the life of patients. microRNAs are small non-coding RNA molecules that regulate the growth and apoptosis of cells. We aimed to investigate the regulation and mechanism of microRNA (miR-143) in the proliferation and apoptosis of prostate cancer LNCap cells. Material/Methods miR-143 and control scramble miRNA were synthesized and respectively transfected into LNCap cells. The proliferation and apoptosis were detected by MTT assay, flow cytometry, and caspase-3 activity assay. The intracellular expression of Bcl-2 was determined by Western blot. Further, LNCap cells were transfected with small interfering RNA (siRNA) targeting Bcl-2 (siBcl-2) or plasmid expressing Bcl-2, followed by transfection of miR-143 or control miRNA. Bcl-2 expression was detected by Western blot, and cell apoptosis was measured by caspase-3 activity assay. Results Transfection of miR-143 significantly inhibited the proliferation of LNCap cells (P=0.0073), increased the percentage of externalized phosphatidylserine (P=0.0042), activated the caspase-3 (P=0.0012), and decreased the expression of Bcl-2 (P=0.012) when compared with the control miRNA group. The expression of Bcl-2 was significantly reduced after siBcl-2 transfection. The apoptosis in the siBcl-2+miR-143 group was significantly increased compared with that in the miR-143 group (P=0.036), whereas there was no significant difference in the apoptosis between the siBcl-2+miRNA and miRNA groups. The expression of Bcl-2 was obviously higher after the transfection of Bcl-2-expressing plasmid. The apoptosis in Bcl-2+miR-143 group was significantly reduced compared with the miR-143 group (P=0.031), whereas no significant difference in the apoptosis was detected between the miRNA and Bcl-2+miRNA groups. Conclusions Transfection of miR-143 induces the apoptosis of prostate cancer LNCap cells by down-regulating Bcl-2 expression, suggesting that Bcl-2 might be a potential therapeutic

  15. miR-143 inhibits bladder cancer cell proliferation and enhances their sensitivity to gemcitabine by repressing IGF-1R signaling

    PubMed Central

    Wang, Hengbing; Li, Qi; Niu, Xiaobing; Wang, Gongcheng; Zheng, Sinian; Fu, Guangbo; Wang, Zengjun

    2017-01-01

    microRNAs (miRNAs) are a class of small RNAs that regulate gene expression. It has been demonstrated that aberrant miRNA expression is associated with cancer development and carcinogenesis. Altered miRNA expression has been suggested to occur in bladder cancer. In other cancer systems, studies have indicated that miR-143, as a tumor suppressor gene, plays essential roles in cancer progression. However, its role in bladder cancer has yet to be elucidated. In the present study, we observed that miR-143 expression was downregulated in human bladder cancer tissues and cells, and that its levels were negatively correlated with bladder cancer clinical stages. We further demonstrated that insulin-like growth factor-1 receptor (IGF-1R) is a functional target of miR-143. Their expression levels were inversely correlated in bladder cancer samples. Overexpression of miR-143 inhibited cell proliferation and promoted chemosensitivity of bladder cancer 5637 cells to gemcitabine. Consistently, small interfering RNA-mediated knockdown of IGF-1R phenocopied miR-143 overexpression. Notably, the expression of IGF-1R is a predictor of patient prognosis. Collectively, our findings indicate that miR-143 is a valuable biomarker for bladder cancer. The miR-143/IGF-1R axis is associated with bladder cancer drug resistance and patient survival. PMID:28123579

  16. Serum Response Factor Regulates Expression of PTEN through a Micro-RNA Network in Vascular Smooth Muscle Cells

    PubMed Central

    Horita, Henrick N; Simpson, Peter A.; Ostriker, Allison; Furgeson, Seth; Van Putten, Vicki; Weiser-Evans, Mary C.M.; Nemenoff, Raphael A.

    2011-01-01

    Objective Serum response factor (SRF) is a critical transcription factor in smooth muscle cells (SMC) controlling differentiation and proliferation. Our previous work demonstrated that depleting SRF in cultured SMC decreased expression of SMC markers, but increased proliferation and inflammatory mediators. A similar phenotype has been observed in SMC silenced for PTEN, suggesting that SRF and PTEN may lie on a common pathway. Our goal was to determine the effect of SRF depletion on PTEN levels, and define mechanisms mediating this effect. Methods and Results In SRF-silenced SMC, PTEN protein, but not mRNA levels were decreased, suggesting post-transcriptional regulation. Re-introduction of PTEN into SRF-depleted SMC reversed increases in proliferation and cytokine/chemokine production, but had no effect on SMC marker expression. SRF-depleted cells showed decreased levels of miR-143, and increased miR-21, which was sufficient to suppress PTEN. Increased miR-21 expression was dependent on induction of FRA-1, which is a direct target of miR-143. Introducing miR-143 into SRF-depleted SMC reduced FRA-1 expression and miR-21 levels and restored PTEN expression. Conclusions SRF regulates PTEN expression in SMC through a miR network involving miR-143, targeting FRA-1, which regulates miR-21. Cross talk between SRF and PTEN likely represents a critical axis in phenotypic remodeling of SMC. PMID:21940949

  17. MiR-143/145 deficiency protects against progression of atherosclerosis in Ldlr−/− mice

    PubMed Central

    Sala, Federica; Aranda, Juan F.; Rotllan, Noemi; Ramírez, Cristina M.; Aryal, Binod; Elia, Leonardo; Condorelli, Gianluigi; Catapano, Alberico Luigi; Fernández-Hernando, Carlos; Norata, Giuseppe Danilo

    2014-01-01

    Background and Objective The miR-143/145 cluster regulates VSMC specific gene expression, thus controlling differentiation, plasticity and contractile function, and promoting the VSMC phenotypic switch from a contractile/non-proliferative to a migrating/proliferative state. More recently increased miR-145 expression was observed in human carotid atherosclerotic plaques from symptomatic patients. The goal of this study was to investigate the contribution of miR-143/145 during atherogenesis by generating mice lacking miR-143/145 on an Ldlr-deficient background. Methods and Results Ldlr−/− and Ldlr−/−-miR-143/145−/− (DKO) were fed a Western diet (WD) for 16 weeks. At the end of the treatment, the lipid profile and the atherosclerotic lesions were assessed in both groups of mice. Absence of miR-143/145 significantly reduced atherosclerotic plaque size and macrophage infiltration. Plasma total cholesterol levels were lower in DKO and FLPC analysis showed decreased cholesterol content in VLDL and LDL fractions. Interestingly miR-143/145 deficiency per se resulted in increased hepatic and vascular ABCA1 expression. Experiments with the luciferase coding sequence fused to the ABCA1 3’UTR, Western blotting, qRT-PCR and mimicMiR confirmed the direct regulation of ABCA1 expression by miR-145. Conclusions miR-143/145 deficiency significantly reduces atherosclerosis in mice. Therapeutic inhibition of miR-145 might be useful for treating atherosclerotic vascular disease. PMID:25008143

  18. miR-143 inhibits cell proliferation by targeting autophagy-related 2B in non-small cell lung cancer H1299 cells.

    PubMed

    Wei, Jiali; Ma, Zhongliang; Li, Yanli; Zhao, Botao; Wang, Detao; Jin, Yan; Jin, Youxin

    2015-01-01

    microRNAs (miRNAs) are small, non‑coding RNAs involved in multiple biological pathways by regulating post-transcriptional gene expression. Previously, autophagy has been reported to suppress the progression of non-small cell lung cancer (NSCLC). However, how miRNAs regulate autophagy in NSCLC remains to be elucidated. In the present study, the autophagy gene, autophagy-related 2B (ATG2B), was identified as a novel target of miR-143. The overexpression of miR-143 was able to downregulate the expression of atg2b at the transcriptional and translational levels by direct binding to its 3' untranslated region. Cell proliferation was significantly inhibited by the ectopic expression of miR-143 in H1299 cells. Knockdown of ATG2B resulted in a similar phenotype, with the overexpression of miR-143 in NSCLC cells. Furthermore, knockdown of ATG2B and hexokinase 2, a key enzyme in glycolysis and another target of miR-143, co-ordinated to inhibit the proliferation of H1299 cells. The results of the present study demonstrated that miR-143 was a novel and important regulator of autophagy by targeting ATG2B and repression of gene expression in autophagy and high glycolysis had a coordinate effect in H1299 cells. These results suggested that ATG2B may be a new potential therapeutic target for NSCLC. Furthermore, it was implied that interrupting autophagy and glycolysis improves NSCLC therapy.

  19. TGF-β signaling controls FSHR signaling-reduced ovarian granulosa cell apoptosis through the SMAD4/miR-143 axis

    PubMed Central

    Du, Xing; Zhang, Lifan; Li, Xinyu; Pan, Zengxiang; Liu, Honglin; Li, Qifa

    2016-01-01

    Follicle-stimulating hormone receptor (FSHR) and its intracellular signaling control mammalian follicular development and female infertility. Our previous study showed that FSHR is downregulated during follicular atresia of porcine ovaries. However, its role and regulation in follicular atresia remain unclear. Here, we showed that FSHR knockdown induced porcine granulosa cell (pGC) apoptosis and follicular atresia, and attenuated the levels of intracellular signaling molecules such as PKA, AKT and p-AKT. FSHR was identified as a target of miR-143, a microRNA that was upregulated during porcine follicular atresia. miR-143 enhanced pGC apoptosis by targeting FSHR, and reduced the levels of intracellular signaling molecules. SMAD4, the final molecule in transforming growth factor (TGF)-β signaling, bound to the promoter and induced significant downregulation of miR-143 in vitro and in vivo. Activated TGF-β signaling rescued miR-143-reduced FSHR and intracellular signaling molecules, and miR-143-induced pGC apoptosis. Overall, our findings offer evidence to explain how TGF-β signaling influences and FSHR signaling for regulation of pGC apoptosis and follicular atresia by a specific microRNA, miR-143. PMID:27882941

  20. miR-143 decreases COX-2 mRNA stability and expression in pancreatic cancer cells

    SciTech Connect

    Pham, Hung; Ekaterina Rodriguez, C.; Donald, Graham W.; Hertzer, Kathleen M.; Jung, Xiaoman S.; Chang, Hui-Hua; Moro, Aune; Reber, Howard A.; Hines, O. Joe; Eibl, Guido

    2013-09-13

    Highlights: •Pancreatic cancer cells express low miR-143 levels and elevated p-MEK, p-MAPK and RREB1. •MEK inhibitors U0126 and PD98059 increase miR-143 expression. •miR-143 decreases COX-2 mRNA stability and expression and PGE{sub 2}. •miR-143 decreases p-p38MAPK, p-MEK, p-MAPK and RREB1 expression. -- Abstract: Small non-coding RNAs, microRNAs (miRNA), inhibit the translation or accelerate the degradation of message RNA (mRNA) by targeting the 3′-untranslated region (3′-UTR) in regulating growth and survival through gene suppression. Deregulated miRNA expression contributes to disease progression in several cancers types, including pancreatic cancers (PaCa). PaCa tissues and cells exhibit decreased miRNA, elevated cyclooxygenase (COX)-2 and increased prostaglandin E{sub 2} (PGE{sub 2}) resulting in increased cancer growth and metastases. Human PaCa cell lines were used to demonstrate that restoration of miRNA-143 (miR-143) regulates COX-2 and inhibits cell proliferation. miR-143 were detected at fold levels of 0.41 ± 0.06 in AsPC-1, 0.20 ± 0.05 in Capan-2 and 0.10 ± 0.02 in MIA PaCa-2. miR-143 was not detected in BxPC-3, HPAF-II and Panc-1 which correlated with elevated mitogen-activated kinase (MAPK) and MAPK kinase (MEK) activation. Treatment with 10 μM of MEK inhibitor U0126 or PD98059 increased miR-143, respectively, by 187 ± 18 and 152 ± 26-fold in BxPC-3 and 182 ± 7 and 136 ± 9-fold in HPAF-II. miR-143 transfection diminished COX-2 mRNA stability at 60 min by 2.6 ± 0.3-fold in BxPC-3 and 2.5 ± 0.2-fold in HPAF-II. COX-2 expression and cellular proliferation in BxPC-3 and HPAF-II inversely correlated with increasing miR-143. PGE{sub 2} levels decreased by 39.3 ± 5.0% in BxPC-3 and 48.0 ± 3.0% in HPAF-II transfected with miR-143. Restoration of miR-143 in PaCa cells suppressed of COX-2, PGE{sub 2}, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression.

  1. MiR-143 targets CTGF and exerts tumor-suppressing functions in epithelial ovarian cancer

    PubMed Central

    Wang, Lufei; He, Jin; Xu, Hongmei; Xu, Longjie; Li, Na

    2016-01-01

    A series of recent studies suggested that miR-143 might involve in the tumorigenesis and metastasis of various cancer types. However, the biological function and underlying mechanisms of miR-143 in human epithelial ovarian carcinoma (EOC) remain unknown. Therefore, this study aimed to investigate the miR-143 expression and its clinical diagnosis significance in patients suffering EOC and to analyze its role and underlying molecular mechanism in EOC. Our result showed that the expression levels of miR-143 were downregulated in EOC tissues and cell lines, was associated with International Federation of Gynaecology and Obstetrics (FIGO) stage, pathological grade and lymph node metastasis (all P < 0.01) . Overexpression of miR-143 significantly inhibited EOC cell proliferation, migration, and invasion. Furthermore, computational algorithm combined with luciferase reporter assays identified connective tissue growth factor (CTGF) as the direct target of miR-143 in EOC cells. The expression level of CTGF was significantly increased in EOC tissues, was inversely correlated with miR-143 expression in clinical EOC tissues. Knockdown of CTGF mimicked the suppression effect induced by miR-143 overexpression. Restoration of CTGF expression partially reversed the suppression effect induced by miR-143 overexpression. These results suggested that miR-143 inhibited EOC cell proliferation, migration, and invasion, at least in part, via suppressing CTGF expression. PMID:27398154

  2. Stromal expression of miR-143/145 promotes neoangiogenesis in lung cancer development

    PubMed Central

    Dimitrova, Nadya; Gocheva, Vasilena; Bhutkar, Arjun; Resnick, Rebecca; Jong, Robyn M.; Miller, Kathryn M.; Bendor, Jordan; Jacks, Tyler

    2015-01-01

    The two unrelated miRNAs, miR-143 and miR-145, co-expressed from the miR-143/145 cluster have been proposed to act as tumor suppressors in human cancer and therapeutic benefits of delivering miR-143 and miR-145 to tumors have been reported. In contrast, we found that tumor-specific deletion of miR-143/145 in an autochthonous mouse model of lung adenocarcinoma did not affect tumor development. This was consistent with the lack of endogenous miR-143/145 expression in normal and transformed lung epithelium. Surprisingly, miR-143/145 in the tumor microenvironment dramatically promoted tumor growth by stimulating the proliferation of endothelial cells. Loss of miR-143/145 in vivo led to derepression of the miR-145 target Camk1d, an inhibitory kinase, which when overexpressed prevents mitotic entry of endothelial cells. As a consequence, tumors in miR-143/145-deficient animals exhibited diminished neoangiogenesis, increased apoptosis and their expansion was limited by the tumor’s ability to co-opt the alveolar vasculature. These findings demonstrate that stromal miR-143/145 promotes tumorigenesis and cautions against the use of these miRNAs as agents in cancer therapeutics. PMID:26586766

  3. miR-143 Overexpression Impairs Growth of Human Colon Carcinoma Xenografts in Mice with Induction of Apoptosis and Inhibition of Proliferation

    PubMed Central

    Borralho, Pedro M.; Simões, André E. S.; Gomes, Sofia E.; Lima, Raquel T.; Carvalho, Tânia; Ferreira, Duarte M. S.; Vasconcelos, Maria H.; Castro, Rui E.; Rodrigues, Cecília M. P.

    2011-01-01

    Background MicroRNAs (miRNAs) are aberrantly expressed in human cancer and involved in the (dys)regulation of cell survival, proliferation, differentiation and death. Specifically, miRNA-143 (miR-143) is down-regulated in human colon cancer. In the present study, we evaluated the role of miR-143 overexpression on the growth of human colon carcinoma cells xenografted in nude mice (immunodeficient mouse strain: N: NIH(s) II-nu/nu). Methodology/Principal Findings HCT116 cells with stable miR-143 overexpression (Over-143) and control (Empty) cells were subcutaneously injected into the flanks of nude mice, and tumor growth was evaluated over time. Tumors arose ∼ 14 days after tumor cell implantation, and the experiment was ended at 40 days after implantation. miR-143 was confirmed to be significantly overexpressed in Over-143 versus Empty xenografts, by TaqMan® Real-time PCR (p<0.05). Importantly, Over-143 xenografts displayed slower tumor growth compared to Empty xenografts from 23 until 40 days in vivo (p<0.05), with final volumes of 928±338 and 2512±387 mm3, respectively. Evaluation of apoptotic proteins showed that Over-143 versus Empty xenografts displayed reduced Bcl-2 levels, and increased caspase-3 activation and PARP cleavage (p<0.05). In addition, the incidence of apoptotic tumor cells, assessed by TUNEL, was increased in Over-143 versus Empty xenografts (p<0.01). Finally, Over-143 versus Empty xenografts displayed significantly reduced NF-κB activation and ERK5 levels and activation (p<0.05), as well as reduced proliferative index, evaluated by Ki-67 immunohistochemistry (p<0.01). Conclusions Our results suggest that reduced tumor volume in Over-143 versus Empty xenografts may result from increased apoptosis and decreased proliferation induced by miR-143. This reinforces the relevance of miR-143 in colon cancer, indicating an important role in the control of in vivo tumor progression, and suggesting that miR-143 may constitute a putative novel

  4. Evaluation of miR-9 and miR-143 expression in urine specimens of sulfur mustard exposed patients.

    PubMed

    Khafaei, Mostafa; Samie, Shahram; Mowla, Seyed Javad; Alvanegh, Akbar Ghorbani; Mirzaei, Behnaz; Chavoshei, Somaye; Dorraj, Ghamar Soltan; Esmailnejad, Mostafa; Tavallaie, Mahmood; Nourani, Mohammadreza

    2015-12-01

    Sulfur mustard (SM) or mustard gas is a chemical alkylating agent that causes blisters in the skin (blister gas), burns the eyes and causes lung injury. Some major cellular pathways are involved in the damage caused by mustard gas such as NF-κb signaling, TGF-β signaling, WNT pathway, inflammation, DNA repair and apoptosis. MicroRNAs are non-coding small RNAs (19-25 nucleotides) that are involved in the regulation of gene expression and are found in two forms, extracellular and intracellular. Changes in the levels of extracellular microRNAs are directly associated with many diseases, it is thus common to study the level of extracellular microRNAs as a biomarker to determine the pathophysiologic status. In this study, 32 mustard gas injured patients and 32healthy subjects participated. Comparative evaluation of miR-9 and miR-143 expression in urine samples was performed by Real Time PCR and Graph Pad software. The Mann Whitney t-test analysis of data showed that the expression level of miR-143 and miR-9 had a significant decrease in sulfur mustard individuals with the respective p-value of 0.0480 and 0.0272 compared to normal samples, with an imbalance of several above mentioned pathways. It seems that reducing the expression level of these genes has a very important role in the pathogenicity of mustard gas injured patients.

  5. Low miR-143/miR-145 Cluster Levels Induce Activin A Overexpression in Oral Squamous Cell Carcinomas, Which Contributes to Poor Prognosis

    PubMed Central

    Bufalino, Andreia; Cervigne, Nilva K.; de Oliveira, Carine Ervolino; Fonseca, Felipe Paiva; Rodrigues, Priscila Campioni; Macedo, Carolina Carneiro Soares; Sobral, Lays Martin; Miguel, Marcia Costa; Lopes, Marcio Ajudarte; Leme, Adriana Franco Paes; Lambert, Daniel W.; Salo, Tuula A.; Kowalski, Luiz Paulo; Graner, Edgard; Coletta, Ricardo D.

    2015-01-01

    Deregulated expression of activin A is reported in several tumors, but its biological functions in oral squamous cell carcinoma (OSCC) are unknown. Here, we investigate whether activin A can play a causal role in OSCCs. Activin A expression was assessed by qPCR and immunohistochemistry in OSCC tissues. Low activin A-expressing cells were treated with recombinant activin A and assessed for apoptosis, proliferation, adhesion, migration, invasion and epithelial-mesenchymal transition (EMT). Those phenotypes were also evaluated in high activin A-expressing cells treated with follistatin (an activin A antagonist) or stably expressing shRNA targeting activin A. Transfections of microRNA mimics were performed to determine whether the overexpression of activin A is regulated by miR-143/miR-145 cluster. Activin A was overexpressed in OSCCs in comparison with normal oral mucosa, and high activin A levels were significantly associated with lymph node metastasis, tumor differentiation and poor survival. High activin A levels promoted multiple properties associated with malignant transformation, including decreased apoptosis and increased proliferation, migration, invasion and EMT. Both miR-143 and miR-145 were markedly downregulated in OSCC cell lines and in clinical specimens, and inversely correlated to activin A levels. Forced expression of miR-143 and miR-145 in OSCC cells significantly decreased the expression of activin A. Overexpression of activin A in OSCCs, which is controlled by downregulation of miR-143/miR-145 cluster, regulates apoptosis, proliferation and invasiveness, and it is clinically correlated with lymph node metastasis and poor survival. PMID:26317418

  6. Tumor suppressors miR-143 and miR-145 and predicted target proteins API5, ERK5, K-RAS, and IRS-1 are differentially expressed in proximal and distal colon.

    PubMed

    Pekow, Joel; Meckel, Katherine; Dougherty, Urszula; Butun, Fatma; Mustafi, Reba; Lim, John; Crofton, Charis; Chen, Xindi; Joseph, Loren; Bissonnette, Marc

    2015-02-01

    The colon differs regionally in local luminal environment, excretory function, and gene expression. Polycistronic microRNA (miR)-143 and miR-145 are downregulated early in colon cancer. We asked if these microRNAs (miRNAs) might be differentially expressed in the proximal vs. the distal colon, contributing to regional differences in protein expression. Primary transcripts and mature miR-143 and miR-145 were quantified by real-time PCR, putative targets were measured by Western blotting, and DNA methylation was assessed by sequencing bisulfite-treated DNA in proximal and distal normal colonic mucosa as well as colon cancers. Putative targets of these miRNAs were assessed following transfection with miR-143 or miR-145. Mean expression of mature miR-143 and miR-145 was 2.0-fold (P < 0.001) and 1.8-fold (P = 0.03) higher, respectively, in proximal than distal colon. DNA methylation or primary transcript expression of these miRNAs did not differ by location. In agreement with increased expression of miR-143 and miR-145 in proximal colon, predicted targets of these miRNAs, apoptosis inhibitor 5 (API5), ERK5, K-RAS, and insulin receptor substrate 1 (IRS-1), which are cell cycle and survival regulators, were expressed at a lower level in proximal than distal colon. Transfection of HCA-7 colon cancer cells with miR-145 downregulated IRS-1, and transfection of HT-29 colon cancer cells with miR-143 decreased K-RAS and ERK5 expression. In conclusion, miR-143 and miR-145 and the predicted target proteins API5, ERK5, K-RAS, and IRS-1 display regional differences in expression in the colon. We speculate that differences in these tumor suppressors might contribute to regional differences in normal colonic gene expression and modulate site-specific differences in malignant predisposition.

  7. microRNAs Distinctively Regulate Vascular Smooth Muscle and Endothelial Cells: Functional Implications in Angiogenesis, Atherosclerosis, and In-Stent Restenosis

    PubMed Central

    Santulli, Gaetano

    2016-01-01

    Endothelial cells (EC) and vascular smooth muscle cells (VSMC) are the main cell types within the vasculature. We describe here how microRNAs (miRs)—noncoding RNAs that can regulate gene expression via translational repression and/or post-transcriptional degradation—distinctively modulate EC and VSMC function in physiology and disease. In particular, the specific roles of miR-126 and miR-143/145, master regulators of EC and VSMC function, respectively, are deeply explored. We also describe the mechanistic role of miRs in the regulation of the pathophysiology of key cardiovascular processes including angiogenesis, atherosclerosis, and in-stent restenosis post-angioplasty. Drawbacks of currently available therapeutic options are discussed, pointing at the challenges and potential clinical opportunities provided by miR-based treatments. PMID:26662986

  8. 18F-FDG PET/CT for Monitoring the Response of Breast Cancer to miR-143-Based Therapeutics by Targeting Tumor Glycolysis

    PubMed Central

    Miao, Ying; Zhang, Ling-fei; Guo, Rui; Liang, Sheng; Zhang, Min; Shi, Shuo; Shang-Guan, Cheng-fang; Liu, Mo-fang; Li, Biao

    2016-01-01

    Increased glucose utilization is a hallmark of cancer, and tumor metabolism is emerging as anticancer target for therapeutic intervention. Triple-negative breast cancers TNBC are highly glycolytic and show poor clinical outcomes. We previously identified hexokinase 2, the major glycolytic enzyme, as a target gene of miR-143 in TNBC. Here, we developed a therapeutic formulation using cholesterol-modified miR-143 agomir encapsulated in a neutral lipid-based delivery agent that blocked tumor growth and glucose metabolism in TNBC tumor-bearing mice when administered systemically. The antioncogenic effects were accompanied by a reduction in the direct target hexokinase 2 and [18F]-fluorodeoxyglucose (18F-FDG) uptake based on positron emission tomography/computed tomography. Treatment with miR-143 formulation has minimal toxic effects and mice tolerated it well. Thus, we demonstrated that miR-143 is a robust inhibitor of the Warburg effect and an effective therapeutic target for TNBC. In addition, 18F-FDG positron emission tomography/computed tomography can be used to specifically monitor the response of TNBC to miR-143-based therapeutics by targeting tumor glycolysis. PMID:27574783

  9. (18)F-FDG PET/CT for Monitoring the Response of Breast Cancer to miR-143-Based Therapeutics by Targeting Tumor Glycolysis.

    PubMed

    Miao, Ying; Zhang, Ling-Fei; Guo, Rui; Liang, Sheng; Zhang, Min; Shi, Shuo; Shang-Guan, Cheng-Fang; Liu, Mo-Fang; Li, Biao

    2016-01-01

    Increased glucose utilization is a hallmark of cancer, and tumor metabolism is emerging as anticancer target for therapeutic intervention. Triple-negative breast cancers TNBC are highly glycolytic and show poor clinical outcomes. We previously identified hexokinase 2, the major glycolytic enzyme, as a target gene of miR-143 in TNBC. Here, we developed a therapeutic formulation using cholesterol-modified miR-143 agomir encapsulated in a neutral lipid-based delivery agent that blocked tumor growth and glucose metabolism in TNBC tumor-bearing mice when administered systemically. The antioncogenic effects were accompanied by a reduction in the direct target hexokinase 2 and [(18)F]-fluorodeoxyglucose ((18)F-FDG) uptake based on positron emission tomography/computed tomography. Treatment with miR-143 formulation has minimal toxic effects and mice tolerated it well. Thus, we demonstrated that miR-143 is a robust inhibitor of the Warburg effect and an effective therapeutic target for TNBC. In addition, (18)F-FDG positron emission tomography/computed tomography can be used to specifically monitor the response of TNBC to miR-143-based therapeutics by targeting tumor glycolysis.

  10. (18)F-FDG PET/CT for Monitoring the Response of Breast Cancer to miR-143-Based Therapeutics by Targeting Tumor Glycolysis.

    PubMed

    Miao, Ying; Zhang, Ling-Fei; Guo, Rui; Liang, Sheng; Zhang, Min; Shi, Shuo; Shang-Guan, Cheng-Fang; Liu, Mo-Fang; Li, Biao

    2016-08-30

    Increased glucose utilization is a hallmark of cancer, and tumor metabolism is emerging as anticancer target for therapeutic intervention. Triple-negative breast cancers TNBC are highly glycolytic and show poor clinical outcomes. We previously identified hexokinase 2, the major glycolytic enzyme, as a target gene of miR-143 in TNBC. Here, we developed a therapeutic formulation using cholesterol-modified miR-143 agomir encapsulated in a neutral lipid-based delivery agent that blocked tumor growth and glucose metabolism in TNBC tumor-bearing mice when administered systemically. The antioncogenic effects were accompanied by a reduction in the direct target hexokinase 2 and [(18)F]-fluorodeoxyglucose ((18)F-FDG) uptake based on positron emission tomography/computed tomography. Treatment with miR-143 formulation has minimal toxic effects and mice tolerated it well. Thus, we demonstrated that miR-143 is a robust inhibitor of the Warburg effect and an effective therapeutic target for TNBC. In addition, (18)F-FDG positron emission tomography/computed tomography can be used to specifically monitor the response of TNBC to miR-143-based therapeutics by targeting tumor glycolysis.

  11. Association between functional polymorphisms in the promoter of the miR-143/145 cluster and risk of intracranial aneurysm

    PubMed Central

    Sima, Xiutian; Sun, Hong; Zhou, Peizhi; You, Chao; Cai, Bowen

    2017-01-01

    MicroRNAs (miRs)-143/145 are involved in various biological processes related to aneurysm formation and are downregulated in patients with intracranial aneurysm (IA). We aimed to determine whether two functional polymorphisms (i.e. rs4705342 and rs4705343) in the promoter of miR-143/145 are related to IA risk. A case-control study was undertaken to examine the association of rs4705342 and rs4705343 with IA risk, including 565 patients with IA and 622 age- and gender-matched controls. rs4705342 was analysed by TaqMan Assay, and rs4705343 was genotyped using polymerase chain reaction-restriction fragment length polymorphism. miR-143/145 expression was quantified using RT-PCR. rs4705342 was associated with a significantly lower risk of IA, with adjusted ORs of 0.74 (95% CI: 0.58–0.95) for TC genotype carriers and 0.74 (95% CI: 0.59–0.94) for TC/CC genotypes carriers. Individuals carrying the rs4705342 C allele had a reduced risk of IA (adjusted OR = 0.82; 95% CI: 0.68–0.98). Haplotype of the two loci of rs4705342 and rs4705343 showed that the CT haplotype carried a lower IA risk and higher miR-143 level. Moreover, the rs4705342 CC/CT genotypes were associated with higher miR-143 levels. Thus, the rs4705342C-rs4705343T haplotype in the promoter of miR-143/145 cluster may be related to IA development. PMID:28272526

  12. Downregulation of anti-oncomirs miR-143/145 cluster occurs before APC gene aberration in the development of colorectal tumors.

    PubMed

    Kamatani, Akemi; Nakagawa, Yoshihito; Akao, Yukihiro; Maruyama, Naoko; Nagasaka, Mitsuo; Shibata, Tomoyuki; Tahara, Tomomitsu; Hirata, Ichiro

    2013-09-01

    Accumulating data indicate that some microRNAs (miRNAs or miRs) can function as tumor suppressors or oncogenes and as such are important in cancer development. We previously reported that miR-143 and -145 are frequently downregulated in colon adenomas and cancers, acting as tumor suppressors. In this present study, we investigated the relationship between the downregulation of the miR-143/145 cluster and genetic aberrations of adenomatous polyposis coli (APC), which are early genetic events in the development of colorectal tumors. The expression levels of both miRs were determined by performing real-time PCR on tissue samples of familial adenomatous polyposis (FAP), colorectal adenoma, colorectal cancer, and paired non-tumorous tissues. Also, the expression of C- or N-terminus of the APC protein and that of the p53 protein in these tissues were examined immunohistochemically. Our data clearly indicated that the decreased expression of miR-143 and -145 frequently occurred before APC gene aberrations. The downregulation of miR-143 and -145 is thus an important genetic event for the initiation step in colorectal tumor development.

  13. miR-17, miR-21, and miR-143 Enhance Adipogenic Differentiation from Porcine Bone Marrow-Derived Mesenchymal Stem Cells.

    PubMed

    An, Xinglan; Ma, Kuiying; Zhang, Zhiren; Zhao, Tianchuang; Zhang, Xueming; Tang, Bo; Li, Ziyi

    2016-08-01

    Bone marrow-derived mesenchymal stem cells (BMSCs) have multilineage differentiation abilities toward adipocytes and osteoblasts. Recently, numerous studies have focused on the roles of microRNAs (miRNAs) in the process of adipogenic differentiation of human and mouse cells. However, the role of miRNAs in adipogenic differentiation process of porcine BMSCs (pBMSCs) remains unclear. In this study, pBMSCs were induced to differentiate into adipocytes using a chemical approach, and the roles of miR-17, miR-21, and miR-143 in this process were investigated. Our results showed that pBMSCs could be chemically induced to differentiate into adipocytes and that the expression of miR-17, miR-21, and miR-143 increased during differentiation. Then, overexpression of mimics of miR-17, miR-21, and miR-143 increased the number of oil red O-positive cells of adipocyte differentiation. The expression levels of CCAAT/enhancer-binding protein alpha (C/EBPα) mRNA showed increases of 1.8-, 1.5-, and 1.2-fold in the groups expressing mimics of miR-21, miR-17, and miR-143, respectively, at day 20. These results demonstrate that miR-17, miR-21, and miR-143 are involved in and promote the adipogenic differentiation of pBMSCs. This study provides an experimental basis for establishing a stable and efficient adipogenic differentiation model for applications in cell therapy and tissue engineering.

  14. MicroRNA Transcriptome Profile Analysis in Porcine Muscle and the Effect of miR-143 on the MYH7 Gene and Protein.

    PubMed

    Zuo, Jianjun; Wu, Fan; Liu, Yihua; Xiao, Juan; Xu, Mei; Yu, Qinping; Xia, Minhao; He, Xiaojun; Zou, Shigeng; Tan, Huize; Feng, Dingyuan

    2015-01-01

    Porcine skeletal muscle fibres are classified based on their different physiological and biochemical properties. Muscle fibre phenotype is regulated by several independent signalling pathways, including the mitogen-activated protein kinase (MAPK), nuclear factor of activated T cells (NFAT), myocyte enhancer factor 2 (MEF2) and peroxisome proliferator-activated receptor (PPAR) signalling pathways. MicroRNAs are non-coding small RNAs that regulate many biological processes. However, their function in muscle fibre type regulation remains unclear. The aim of our study was to identify miRNAs that regulate muscle fibre type during porcine growth to help understand the miRNA regulation mechanism of fibre differentiation. We performed Solexa/Illumina deep sequencing for the microRNAome during 3 muscle growth stages (63, 98 and 161 d). In this study, 271 mature miRNAs and 243 pre-miRNAs were identified. We detected 472 novel miRNAs in the muscle samples. Among the mature miRNAs, there are 23 highest expression miRNAs (over 10,000 RPM), account for 85.3% of the total counts of mature miRNAs., including 10 (43.5%) muscle-related miRNAs (ssc-miR-133a-3p, ssc-miR-486, ssc-miR-1, ssc-miR-143-3p, ssc-miR-30a-5p, ssc-miR-181a, ssc-miR-148a-3p, ssc-miR-92a, ssc-miR-21, ssc-miR-126-5p). Particularly, both ssc-miR-1 and ssc-miR-133 belong to the MyomiRs, which control muscle myosin content, myofibre identity and muscle performance. The involvement of these miRNAs in muscle fibre phenotype provides new insight into the mechanism of muscle fibre regulation underlying muscle development. Furthermore, we performed cell transfection experiment. Overexpression/inhibition of ssc-miR-143-3p in porcine skeletal muscle satellite cell induced an/a increase/reduction of the slow muscle fibre gene and protein (MYH7), indicating that miR-143 activity regulated muscle fibre differentiate in skeletal muscle. And it regulate MYH7 through the HDAC4-MEF2 pathway.

  15. A polymorphism rs4705341 in the flanking region of miR-143/145 predicts risk and prognosis of colorectal cancer

    PubMed Central

    Li, Lijuan; Sun, Hong; Nie, Xinwen; Liang, Yundan; Yuan, Fang; Pu, Yan; Bai, Peng; Zhang, Lin; Gao, Linbo

    2016-01-01

    The aim of this study was to investigate the effect of a polymorphism rs4705341 in the flanking region of miR-143/145 on the risk of colorectal cancer (CRC). The rs4705341 polymorphism was analyzed in 1002 cases and 1062 controls using a polymerase chain reaction-restriction fragment length polymorphism method. We found a significantly reduced CRC susceptibility with miR-143/145 rs4705341 in homozygote comparison (adjusted OR = 0.66, 95%CI, 0.50-0.88, P = 0.004), dominant genetic model (adjusted OR = 0.80, 95%CI, 0.67-0.96, P = 0.015), recessive genetic model (adjusted OR = 0.73, 95%CI, 0.56-0.94, P = 0.016), and allele comparison (adjusted OR = 0.83, 95%CI, 0.73-0.94, P = 0.004). Stratification analysis showed that the rs4705341 was related to differentiated status, clinical stage I-II, and patients without lymph node metastasis. Moreover, patients with rs4705341GG had a longer overall survival (adjusted HR = 5.57, 95%CI, 0.95-32.68). These findings indicate that the miR-143/145 rs4705341 may be used as a potential biomarker for the development and prognosis of CRC. PMID:27556691

  16. miR-143 inhibits oncogenic traits by degrading NUAK2 in glioblastoma.

    PubMed

    Fu, Ting-Gang; Wang, Ling; Li, Wei; Li, Jian-Zhong; Li, Jian

    2016-06-01

    Despite evidence that the crucial role of NUAK family, SNF1-like kinase, 2 [NUAK2; also known as sucrose non-fermenting 1 (SNF1)-like kinase (SNARK)], has been highlighted in cancer development and in tumor progression, to the best of our knowledge, there are no studies available to date on the role of NUAK2 in glioblastoma. Thus, in this study, in order to determine the role of NUAK2 in glioblastoma, we performed western blot analysis to detect its expression in glioma. The results demonstrated that NUAK2 expression was upregulated in glioma tissues and that its expression was associated with the advanced stages of the disease. In vitro, NUAK2 overexpression promoted the proliferation, migration and invasion of A172 glioblastoma cells, whereas the silencing of NUAK2 with a plasmid carrying shRNA targeting NUAK2 inhibited the proliferation of A172 glioblastoma cells. Moreover, NUAK2 regulated cancer stem cell (CSC)-related gene expression in the glioblastoma cells. We performed an analysis of potential microRNA (miR or miRNA) target sites using 3 commonly used prediction algorithms, miRanda, TargetScan and PicTar. All 3 algorithms predicted that miR‑143 targeted the 3'-untranslated region (3'UTR) of NUAK2. Subsequent experiments confirmed this prediction. Finally, we found that miR‑143 inhibited the proliferation, migration and invasion of the glioblastoma cells. Thus, the findings of the present study demonstrate that miR‑143 inhibits oncogenic traits by degrading NUAK2 in glioblastoma.

  17. Dysregulated miR-103 and miR-143 expression in peripheral blood mononuclear cells from induced prediabetes and type 2 diabetes rats.

    PubMed

    Vatandoost, Nasimeh; Amini, Masoud; Iraj, Bijan; Momenzadeh, Sedigheh; Salehi, Rasoul

    2015-11-01

    The progression from normal glucose tolerance (NGT) to type 2 diabetes (T2D) occurs through an intermediate state of glucose intolerance known as pre-diabetes. This transition is usually a gradual phenomenon that occurs over 5-10 years. Among the routinely practiced T2D screening criteria, like, FPG, IFG, IGT or HbA1c, still the issue of a preferable one is debated. The newly emerged microRNAs are created much hope to act as a class of suitable diabetes gene signature detectable at an early stage of the disease development. Although T2D related miRNA fluctuations are reported from the main insulin target organs, sampling of these organs for the sake of screening due to its invasive nature is not practicable. Peripheral blood mononuclear cells (PBMCs) are in constant touch with all body organs hence may exhibit the trace of miRNA changes which take place in insulin target organs. In this study we have evaluated miR-103 and miR-143 expression in three groups of rats namely; normal control, high fat diet (HFD) which is corresponding to prediabetes state, and high fat diet/streptozotocin (STZ) induced T2D. Quantitative real time PCR was used for profiling the selected miRNA expression at various time intervals of the three defined groups of rats. In prediabetes and overt diabetes stages, miR-103 showed significantly elevated expression in PBMC specimens compared to the normal healthy control group. Overexpression pattern of mir-143 was statistically significant in T2D compared to non-diabetic controls. However in HFD (prediabetic) rats also we observed an increasing pattern of miR-143 compared to the normal controls but it was not statistically significant.

  18. RNA-binding protein RBM3 prevents NO-induced apoptosis in human neuroblastoma cells by modulating p38 signaling and miR-143

    PubMed Central

    Yang, Hai-Jie; Ju, Fei; Guo, Xin-Xin; Ma, Shuang-Ping; Wang, Lei; Cheng, Bin-Feng; Zhuang, Rui-Juan; Zhang, Bin-Bin; Shi, Xiang; Feng, Zhi-Wei; Wang, Mian

    2017-01-01

    Nitric oxide (NO)-induced apoptosis in neurons is an important cause of neurodegenerative disease in humans. The cold-inducible protein RBM3 mediates the protective effects of cooling on apoptosis induced by various insults. However, whether RBM3 protects neural cells from NO-induced apoptosis is unclear. This study aimed to investigate the neuroprotective effect of RBM3 on NO-induced apoptosis in human SH-SY5Y neuroblastoma cells. Firstly, we demonstrated that mild hypothermia (32 °C) induces RBM3 expression and confers a potent neuroprotective effect on NO-induced apoptosis, which was substantially diminished when RBM3 was silenced by siRNA. Moreover, overexpression of RBM3 exhibited a strong protective effect against NO-induced apoptosis. Signaling pathway screening demonstrated that only p38 inhibition by RBM3 provided neuroprotective effect, although RBM3 overexpression could affect the activation of p38, JNK, ERK, and AKT signaling in response to NO stimuli. Notably, RBM3 overexpression also blocked the activation of p38 signaling induced by transforming growth factor-β1. Furthermore, both RBM3 overexpression and mild hypothermia abolished the induction of miR-143 by NO, which was shown to mediate the cytotoxicity of NO in a p38-dependent way. These findings suggest that RBM3 protects neuroblastoma cells from NO-induced apoptosis by suppressing p38 signaling, which mediates apoptosis through miR-143 induction. PMID:28134320

  19. RNA-binding protein RBM3 prevents NO-induced apoptosis in human neuroblastoma cells by modulating p38 signaling and miR-143.

    PubMed

    Yang, Hai-Jie; Ju, Fei; Guo, Xin-Xin; Ma, Shuang-Ping; Wang, Lei; Cheng, Bin-Feng; Zhuang, Rui-Juan; Zhang, Bin-Bin; Shi, Xiang; Feng, Zhi-Wei; Wang, Mian

    2017-01-30

    Nitric oxide (NO)-induced apoptosis in neurons is an important cause of neurodegenerative disease in humans. The cold-inducible protein RBM3 mediates the protective effects of cooling on apoptosis induced by various insults. However, whether RBM3 protects neural cells from NO-induced apoptosis is unclear. This study aimed to investigate the neuroprotective effect of RBM3 on NO-induced apoptosis in human SH-SY5Y neuroblastoma cells. Firstly, we demonstrated that mild hypothermia (32 °C) induces RBM3 expression and confers a potent neuroprotective effect on NO-induced apoptosis, which was substantially diminished when RBM3 was silenced by siRNA. Moreover, overexpression of RBM3 exhibited a strong protective effect against NO-induced apoptosis. Signaling pathway screening demonstrated that only p38 inhibition by RBM3 provided neuroprotective effect, although RBM3 overexpression could affect the activation of p38, JNK, ERK, and AKT signaling in response to NO stimuli. Notably, RBM3 overexpression also blocked the activation of p38 signaling induced by transforming growth factor-β1. Furthermore, both RBM3 overexpression and mild hypothermia abolished the induction of miR-143 by NO, which was shown to mediate the cytotoxicity of NO in a p38-dependent way. These findings suggest that RBM3 protects neuroblastoma cells from NO-induced apoptosis by suppressing p38 signaling, which mediates apoptosis through miR-143 induction.

  20. Interstitial cells: regulators of smooth muscle function.

    PubMed

    Sanders, Kenton M; Ward, Sean M; Koh, Sang Don

    2014-07-01

    Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα(+) cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα(+) cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues.

  1. Interstitial Cells: Regulators of Smooth Muscle Function

    PubMed Central

    Sanders, Kenton M.; Ward, Sean M.; Koh, Sang Don

    2014-01-01

    Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα+ cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα+ cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues. PMID:24987007

  2. Regulation of Gastrointestinal Smooth Muscle Function by Interstitial Cells.

    PubMed

    Sanders, Kenton M; Kito, Yoshihiko; Hwang, Sung Jin; Ward, Sean M

    2016-09-01

    Interstitial cells of mesenchymal origin form gap junctions with smooth muscle cells in visceral smooth muscles and provide important regulatory functions. In gastrointestinal (GI) muscles, there are two distinct classes of interstitial cells, c-Kit(+) interstitial cells of Cajal and PDGFRα(+) cells, that regulate motility patterns. Loss of these cells may contribute to symptoms in GI motility disorders.

  3. TGF-β1 promotes colorectal cancer immune escape by elevating B7-H3 and B7-H4 via the miR-155/miR-143 axis

    PubMed Central

    Zhu, Jianjie; Meng, Fanyi; Chen, Qi; Tao, Lihua; Li, Rui; Fu, Fengqing; Liu, Cuiping; Hu, Yuanjia; Wang, Weipeng; Zhang, Hongjian; Hua, Dong; Chen, Weichang; Zhang, Xueguang

    2016-01-01

    Transforming growth factor-beta 1 (TGF-β1) suppresses T cell function, promoting tumor immune escape. Yet, whether the depression of TGF-β1 on T cell function is mediated by co-inhibitory molecules B7-H3 and B7-H4 remains largely unclear. Here, we demonstrated that TGF-β1 elevated the expression of miR-155 in colorectal cancer cells through SMAD3 and SMAD4. The upregulated miR-155 attenuated miR-143 by inhibiting its direct target, the transcription factor CEBPB. Consequently, the direct target genes of miR-143, B7-H3 and B7-H4, were augmented in the cytoplasm and membrane of tumor cells. Over-expression of B7-H3 and B7-H4 in HCT-116 cells induced T cells to secrete TGF-β1 and the immunosuppressive cytokines IL-2, IL-6, and IL-17. Restoration of miR-143 inhibited the growth of HCT-116 xenograft tumors in mice, and also repressed the expression of B7-H3 and B7-H4 in the tumors. Thus, this study reveals the mechanism by which TGF-β1 leads to T cell-mediated tumor evasion through an increase in B7-H3 and B7-H4 expression. PMID:27626488

  4. Up-regulated expression of microRNA-143 in association with obesity in adipose tissue of mice fed high-fat diet.

    PubMed

    Takanabe, Rieko; Ono, Koh; Abe, Yukiko; Takaya, Tomohide; Horie, Takahiro; Wada, Hiromichi; Kita, Toru; Satoh, Noriko; Shimatsu, Akira; Hasegawa, Koji

    2008-11-28

    MicroRNAs (miRNAs) are short non-coding RNA that post-transcriptionally regulates gene expression. miR-143 has been proposed to play a role in the differentiation of adipocytes in culture. However, the mechanism regulating the expression of miR-143 in adult adipose tissue during the development of obesity in vivo is unknown. Here in, we showed that the expression of miR-143 in the mesenteric fat was up-regulated in mice fed a high-fat diet. Increased miR-143 expression was associated with an elevated body weight and mesenteric fat weight. Furthermore, miR-143 levels were closely correlated with expression levels of adipocyte differentiation markers such as PPARgamma and aP2 as well as plasma levels of leptin, one of the important adipocytokines involved in insulin resistance. These findings provide the first evidence for the up-regulated expression of miR-143 in the mesenteric fat of high-fat diet-induced obese mice, which might contribute to the regulated expression of adipocyte genes involved in the pathophysiology of obesity.

  5. Elevated Glucose Levels Promote Contractile and Cytoskeletal Gene Expression in Vascular Smooth Muscle via Rho/Protein Kinase C and Actin Polymerization*

    PubMed Central

    Hien, Tran Thi; Turczyńska, Karolina M.; Dahan, Diana; Ekman, Mari; Grossi, Mario; Sjögren, Johan; Nilsson, Johan; Braun, Thomas; Boettger, Thomas; Garcia-Vaz, Eliana; Stenkula, Karin; Swärd, Karl; Gomez, Maria F.; Albinsson, Sebastian

    2016-01-01

    Both type 1 and type 2 diabetes are associated with increased risk of cardiovascular disease. This is in part attributed to the effects of hyperglycemia on vascular endothelial and smooth muscle cells, but the underlying mechanisms are not fully understood. In diabetic animal models, hyperglycemia results in hypercontractility of vascular smooth muscle possibly due to increased activation of Rho-kinase. The aim of the present study was to investigate the regulation of contractile smooth muscle markers by glucose and to determine the signaling pathways that are activated by hyperglycemia in smooth muscle cells. Microarray, quantitative PCR, and Western blot analyses revealed that both mRNA and protein expression of contractile smooth muscle markers were increased in isolated smooth muscle cells cultured under high compared with low glucose conditions. This effect was also observed in hyperglycemic Akita mice and in diabetic patients. Elevated glucose activated the protein kinase C and Rho/Rho-kinase signaling pathways and stimulated actin polymerization. Glucose-induced expression of contractile smooth muscle markers in cultured cells could be partially or completely repressed by inhibitors of advanced glycation end products, L-type calcium channels, protein kinase C, Rho-kinase, actin polymerization, and myocardin-related transcription factors. Furthermore, genetic ablation of the miR-143/145 cluster prevented the effects of glucose on smooth muscle marker expression. In conclusion, these data demonstrate a possible link between hyperglycemia and vascular disease states associated with smooth muscle contractility. PMID:26683376

  6. Regulation of gastrointestinal motility--insights from smooth muscle biology.

    PubMed

    Sanders, Kenton M; Koh, Sang Don; Ro, Seungil; Ward, Sean M

    2012-11-01

    Gastrointestinal motility results from coordinated contractions of the tunica muscularis, the muscular layers of the alimentary canal. Throughout most of the gastrointestinal tract, smooth muscles are organized into two layers of circularly or longitudinally oriented muscle bundles. Smooth muscle cells form electrical and mechanical junctions between cells that facilitate coordination of contractions. Excitation-contraction coupling occurs by Ca(2+) entry via ion channels in the plasma membrane, leading to a rise in intracellular Ca(2+). Ca(2+) binding to calmodulin activates myosin light chain kinase; subsequent phosphorylation of myosin initiates cross-bridge cycling. Myosin phosphatase dephosphorylates myosin to relax muscles, and a process known as Ca(2+) sensitization regulates the activity of the phosphatase. Gastrointestinal smooth muscles are 'autonomous' and generate spontaneous electrical activity (slow waves) that does not depend upon input from nerves. Intrinsic pacemaker activity comes from interstitial cells of Cajal, which are electrically coupled to smooth muscle cells. Patterns of contractile activity in gastrointestinal muscles are determined by inputs from enteric motor neurons that innervate smooth muscle cells and interstitial cells. Here we provide an overview of the cells and mechanisms that generate smooth muscle contractile behaviour and gastrointestinal motility.

  7. Caveolin-1 regulates contractility in differentiated vascular smooth muscle.

    PubMed

    Je, Hyun-Dong; Gallant, Cynthia; Leavis, Paul C; Morgan, Kathleen G

    2004-01-01

    Caveolin is a principal component of caveolar membranes. In the present study, we utilized a decoy peptide approach to define the degree of involvement of caveolin in PKC-dependent regulation of contractility of differentiated vascular smooth muscle. The primary isoform of caveolin in ferret aorta vascular smooth muscle is caveolin-1. Chemical loading of contractile vascular smooth muscle tissue with a synthetic caveolin-1 scaffolding domain peptide inhibited PKC-dependent increases in contractility induced by a phorbol ester or an alpha agonist. Peptide loading also resulted in a significant inhibition of phorbol ester-induced adducin Ser662 phosphorylation, an intracellular monitor of PKC kinase activity, ERK1/2 activation, and Ser789 phosphorylation of the actin binding protein caldesmon. alpha-Agonist-induced ERK1-1/2 activation was also inhibited by the caveolin-1 peptide. Scrambled peptide-loaded tissues or sham-loaded tissues were unaffected with respect to both contractility and signaling. Depolarization-induced activation of contraction was not affected by caveolin peptide loading. Similar results with respect to contractility and ERK1/2 activation during exposure to the phorbol ester or the alpha-agonist were obtained with the cholesterol-depleting agent methyl-beta-cyclodextrin. These results are consistent with a role for caveolin-1 in the coordination of signaling leading to the regulation of contractility of smooth muscle.

  8. Ionic conductances regulating the excitability of colonic smooth muscles.

    PubMed

    Koh, Sang Don; Ward, S M; Sanders, K M

    2012-08-01

    The tunica muscularis of the gastrointestinal (GI) tract contains two layers of smooth muscle cells (SMC) oriented perpendicular to each other. SMC express a variety of voltage-dependent and voltage-independent ionic conductance(s) that develop membrane potential and control excitability. Resting membrane potentials (RMP) vary through the GI tract but generally are within the range of -80 to -40 mV. RMP sets the 'gain' of smooth muscle and regulates openings of voltage-dependent Ca(2+) channels. A variety of K(+) channels contribute to setting RMP of SMC. In most regions, RMP is considerably less negative than the K(+) equilibrium potential, due to a finely tuned balance between background K(+) channels and non-selective cation channels (NSCC). Variations in expression patterns and openings of K(+) channels and NSCC account for differences of the RMP in different regions of the GI tract. Smooth muscle excitability is also regulated by interstitial cells (interstitial cells of Cajal (ICC) and PDGFRα(+) cells) that express additional conductances and are electrically coupled to SMC. Thus, 'myogenic' activity results from the integrated behavior of the SMC/ICC/PDGFRα(+) cell (SIP) syncytium. Inputs from excitatory and inhibitory motor neurons are required to produce the complex motor patterns of the gut. Motor neurons innervate three cell types in the SIP, and receptors, second messenger pathways, and ion channels in these cells mediate postjunctional responses. Studies of isolated SIP cells have begun to unravel the mechanisms responsible for neural responses. This review discusses ion channels that set and regulate RMP of SIP cells and how neurotransmitters regulate membrane potential.

  9. IP3 receptors regulate vascular smooth muscle contractility and hypertension

    PubMed Central

    Lin, Qingsong; Zhao, Guiling; Fang, Xi; Peng, Xiaohong; Tang, Huayuan; Wang, Hong; Jing, Ran; Liu, Jie; Ouyang, Kunfu

    2016-01-01

    Inositol 1, 4, 5-trisphosphate receptor–mediated (IP3R-mediated) calcium (Ca2+) release has been proposed to play an important role in regulating vascular smooth muscle cell (VSMC) contraction for decades. However, whether and how IP3R regulates blood pressure in vivo remains unclear. To address these questions, we have generated a smooth muscle–specific IP3R triple-knockout (smTKO) mouse model using a tamoxifen-inducible system. In this study, the role of IP3R-mediated Ca2+ release in adult VSMCs on aortic vascular contractility and blood pressure was assessed following tamoxifen induction. We demonstrated that deletion of IP3Rs significantly reduced aortic contractile responses to vasoconstrictors, including phenylephrine, U46619, serotonin, and endothelin 1. Deletion of IP3Rs also dramatically reduced the phosphorylation of MLC20 and MYPT1 induced by U46619. Furthermore, although the basal blood pressure of smTKO mice remained similar to that of wild-type controls, the increase in systolic blood pressure upon chronic infusion of angiotensin II was significantly attenuated in smTKO mice. Taken together, our results demonstrate an important role for IP3R-mediated Ca2+ release in VSMCs in regulating vascular contractility and hypertension. PMID:27777977

  10. Smooth muscle FGF/TGFβ cross talk regulates atherosclerosis progression.

    PubMed

    Chen, Pei-Yu; Qin, Lingfeng; Li, Guangxin; Tellides, George; Simons, Michael

    2016-07-01

    The conversion of vascular smooth muscle cells (SMCs) from contractile to proliferative phenotype is thought to play an important role in atherosclerosis. However, the contribution of this process to plaque growth has never been fully defined. In this study, we show that activation of SMC TGFβ signaling, achieved by suppression of SMC fibroblast growth factor (FGF) signaling input, induces their conversion to a contractile phenotype and dramatically reduces atherosclerotic plaque size. The FGF/TGFβ signaling cross talk was observed in vitro and in vivo In vitro, inhibition of FGF signaling increased TGFβ activity, thereby promoting smooth muscle differentiation and decreasing proliferation. In vivo, smooth muscle-specific knockout of an FGF receptor adaptor Frs2α led to a profound inhibition of atherosclerotic plaque growth when these animals were crossed on Apoe(-/-) background and subjected to a high-fat diet. In particular, there was a significant reduction in plaque cellularity, increase in fibrous cap area, and decrease in necrotic core size. In agreement with these findings, examination of human coronary arteries with various degrees of atherosclerosis revealed a strong correlation between the activation of FGF signaling, loss of TGFβ activity, and increased disease severity. These results identify SMC FGF/TGFβ signaling cross talk as an important regulator of SMC phenotype switch and document a major contribution of medial SMC proliferation to atherosclerotic plaque growth.

  11. Smooth Muscle Enriched Long Noncoding RNA (SMILR) Regulates Cell Proliferation

    PubMed Central

    Ballantyne, Margaret D.; Pinel, Karine; Dakin, Rachel; Vesey, Alex T.; Diver, Louise; Mackenzie, Ruth; Garcia, Raquel; Welsh, Paul; Sattar, Naveed; Hamilton, Graham; Joshi, Nikhil; Dweck, Marc R.; Miano, Joseph M.; McBride, Martin W.; Newby, David E.; McDonald, Robert A.

    2016-01-01

    Background— Phenotypic switching of vascular smooth muscle cells from a contractile to a synthetic state is implicated in diverse vascular pathologies, including atherogenesis, plaque stabilization, and neointimal hyperplasia. However, very little is known about the role of long noncoding RNA (lncRNA) during this process. Here, we investigated a role for lncRNAs in vascular smooth muscle cell biology and pathology. Methods and Results— Using RNA sequencing, we identified >300 lncRNAs whose expression was altered in human saphenous vein vascular smooth muscle cells following stimulation with interleukin-1α and platelet-derived growth factor. We focused on a novel lncRNA (Ensembl: RP11-94A24.1), which we termed smooth muscle–induced lncRNA enhances replication (SMILR). Following stimulation, SMILR expression was increased in both the nucleus and cytoplasm, and was detected in conditioned media. Furthermore, knockdown of SMILR markedly reduced cell proliferation. Mechanistically, we noted that expression of genes proximal to SMILR was also altered by interleukin-1α/platelet-derived growth factor treatment, and HAS2 expression was reduced by SMILR knockdown. In human samples, we observed increased expression of SMILR in unstable atherosclerotic plaques and detected increased levels in plasma from patients with high plasma C-reactive protein. Conclusions— These results identify SMILR as a driver of vascular smooth muscle cell proliferation and suggest that modulation of SMILR may be a novel therapeutic strategy to reduce vascular pathologies. PMID:27052414

  12. Fibronectin matrix polymerization regulates smooth muscle cell phenotype through a Rac1 dependent mechanism.

    PubMed

    Shi, Feng; Long, Xiaochun; Hendershot, Allison; Miano, Joseph M; Sottile, Jane

    2014-01-01

    Smooth muscle cells are maintained in a differentiated state in the vessel wall, but can be modulated to a synthetic phenotype following injury. Smooth muscle phenotypic modulation is thought to play an important role in the pathology of vascular occlusive diseases. Phenotypically modulated smooth muscle cells exhibit increased proliferative and migratory properties that accompany the downregulation of smooth muscle cell marker proteins. Extracellular matrix proteins, including fibronectin, can regulate the smooth muscle phenotype when used as adhesive substrates. However, cells produce and organize a 3-dimensional fibrillar extracellular matrix, which can affect cell behavior in distinct ways from the protomeric 2-dimensional matrix proteins that are used as adhesive substrates. We previously showed that the deposition/polymerization of fibronectin into the extracellular matrix can regulate the deposition and organization of other extracellular matrix molecules in vitro. Further, our published data show that the presence of a fibronectin polymerization inhibitor results in increased expression of smooth muscle cell differentiation proteins and inhibits vascular remodeling in vivo. In this manuscript, we used an in vitro cell culture system to determine the mechanism by which fibronectin polymerization affects smooth muscle phenotypic modulation. Our data show that fibronectin polymerization decreases the mRNA levels of multiple smooth muscle differentiation genes, and downregulates the levels of smooth muscle α-actin and calponin proteins by a Rac1-dependent mechanism. The expression of smooth muscle genes is transcriptionally regulated by fibronectin polymerization, as evidenced by the increased activity of luciferase reporter constructs in the presence of a fibronectin polymerization inhibitor. Fibronectin polymerization also promotes smooth muscle cell growth, and decreases the levels of actin stress fibers. These data define a Rac1-dependent pathway wherein

  13. Diversity and plasticity in signaling pathways that regulate smooth muscle responsiveness: Paradigms and paradoxes for the myosin phosphatase, the master regulator of smooth muscle contraction

    PubMed Central

    Eto, Masumi; Kitazawa, Toshio

    2017-01-01

    A hallmark of smooth muscle cells is their ability to adapt their functions to meet temporal and chronic fluctuations in their demands. These functions include force development and growth. Understanding the mechanisms underlying the functional plasticity of smooth muscles, the major constituent of organ walls, is fundamental to elucidating pathophysiological rationales of failures of organ functions. Also, the knowledge is expected to facilitate devising innovative strategies that more precisely monitor and normalize organ functions by targeting individual smooth muscles. Evidence has established a current paradigm that the myosin light chain phosphatase (MLCP) is a master regulator of smooth muscle responsiveness to stimuli. Cellular MLCP activity is negatively and positively regulated in response to G-protein activation and cAMP/cGMP production, respectively, through the MYPT1 regulatory subunit and an endogenous inhibitor protein named CPI-17. In this article we review the outcomes from two decade of research on the CPI-17 signaling and discuss emerging paradoxes in the view of signaling pathways regulating smooth muscle functions through MLCP. PMID:28260704

  14. Cystic Fibrosis Transmembrane Conductance Regulator in Sarcoplasmic Reticulum of Airway Smooth Muscle. Implications for Airway Contractility

    PubMed Central

    Cook, Daniel P.; Rector, Michael V.; Bouzek, Drake C.; Michalski, Andrew S.; Gansemer, Nicholas D.; Reznikov, Leah R.; Li, Xiaopeng; Stroik, Mallory R.; Ostedgaard, Lynda S.; Abou Alaiwa, Mahmoud H.; Thompson, Michael A.; Prakash, Y. S.; Krishnan, Ramaswamy; Meyerholz, David K.; Seow, Chun Y.

    2016-01-01

    Rationale: An asthma-like airway phenotype has been described in people with cystic fibrosis (CF). Whether these findings are directly caused by loss of CF transmembrane conductance regulator (CFTR) function or secondary to chronic airway infection and/or inflammation has been difficult to determine. Objectives: Airway contractility is primarily determined by airway smooth muscle. We tested the hypothesis that CFTR is expressed in airway smooth muscle and directly affects airway smooth muscle contractility. Methods: Newborn pigs, both wild type and with CF (before the onset of airway infection and inflammation), were used in this study. High-resolution immunofluorescence was used to identify the subcellular localization of CFTR in airway smooth muscle. Airway smooth muscle function was determined with tissue myography, intracellular calcium measurements, and regulatory myosin light chain phosphorylation status. Precision-cut lung slices were used to investigate the therapeutic potential of CFTR modulation on airway reactivity. Measurements and Main Results: We found that CFTR localizes to the sarcoplasmic reticulum compartment of airway smooth muscle and regulates airway smooth muscle tone. Loss of CFTR function led to delayed calcium reuptake following cholinergic stimulation and increased myosin light chain phosphorylation. CFTR potentiation with ivacaftor decreased airway reactivity in precision-cut lung slices following cholinergic stimulation. Conclusions: Loss of CFTR alters porcine airway smooth muscle function and may contribute to the airflow obstruction phenotype observed in human CF. Airway smooth muscle CFTR may represent a therapeutic target in CF and other diseases of airway narrowing. PMID:26488271

  15. Power fluctuations smoothing and regulations in wind turbine generator systems

    NASA Astrophysics Data System (ADS)

    Babazadehrokni, Hamed

    Wind is one of the most popular renewable energy sources and it has the potential to become the biggest energy source in future. Since the wind does not always blow constantly, the output wind power is not constant which may make some problem for the power grid. According to the grid code which is set by independent system operator, ISO, wind turbine generator systems need to follow some standards such as the predetermined acceptable power fluctuations. In order to smooth the output powers, the energy storage system and some power electronics modules are employed. The utilized power electronics modules in the wind turbine system can pursue many different goals, such as maintaining the voltage stability, frequency stability, providing the available and predetermined output active and reactive power. On the other side, the energy storage system can help achieving some of these goals but its main job is to store the extra energy when not needed and release the stored energy when needed. The energy storage system can be designed in different sizes, material and also combination of different energy storage systems (hybrid designs). Combination of power electronics devises and also energy storage system helps the wind turbine systems to smooth the output power according to the provided standards. In addition prediction of wind speed may improve the performance of wind turbine generator systems. In this research study all these three topics are studied and the obtained results are written in 10 papers which 7 of them are published and three of them are under process.

  16. Vascular smooth muscle cell spreading onto fibrinogen is regulated by calpains and phospholipase C.

    PubMed

    Paulhe, F; Bogyo, A; Chap, H; Perret, B; Racaud-Sultan, C

    2001-11-09

    Fibrinogen deposition and smooth muscle cell migration are important causes of atherosclerosis and angiogenesis. Involvement of calpains in vascular smooth muscle cell adhesion onto fibrinogen was investigated. Using calpain inhibitors, we showed that activation of calpains was required for smooth muscle cell spreading. An increase of (32)P-labeled phosphatidic acid and phosphatidylinositol-3,4-bisphosphate, respective products of phospholipase C and phosphoinositide 3-kinase activities, was measured in adherent cells. Addition of the calpain inhibitor calpeptin strongly decreased phosphatidic acid and phosphatidylinositol-3,4-bisphosphate. However, smooth muscle cell spreading was prevented by the phospholipase C inhibitor U-73122, but poorly modified by phosphoinositide 3-kinase inhibitors wortmannin and LY-294002. Moreover, PLC was found to act upstream of the PI 3-kinase IA isoform. Thus, our data provide the first evidence that calpains are required for smooth muscle cell spreading. Further, phospholipase C activation is pointed as a key step of cell-spreading regulation by calpains.

  17. Histone deacetylase 8 regulates cortactin deacetylation and contraction in smooth muscle tissues.

    PubMed

    Li, Jia; Chen, Shu; Cleary, Rachel A; Wang, Ruping; Gannon, Olivia J; Seto, Edward; Tang, Dale D

    2014-08-01

    Histone deacetylases (HDACs) are a family of enzymes that mediate nucleosomal histone deacetylation and gene expression. Some members of the HDAC family have also been implicated in nonhistone protein deacetylation, which modulates cell-cycle control, differentiation, and cell migration. However, the role of HDACs in smooth muscle contraction is largely unknown. Here, HDAC8 was localized both in the cytoplasm and the nucleus of mouse and human smooth muscle cells. Knockdown of HDAC8 by lentivirus-encoding HDAC8 shRNA inhibited force development in response to acetylcholine. Treatment of smooth muscle tissues with HDAC8 inhibitor XXIV (OSU-HDAC-44) induced relaxation of precontracted smooth muscle tissues. In addition, cortactin is an actin-regulatory protein that undergoes deacetylation during migration of NIH 3T3 cells. In this study, acetylcholine stimulation induced cortactin deacetylation in mouse and human smooth muscle tissues, as evidenced by immunoblot analysis using antibody against acetylated lysine. Knockdown of HDAC8 by RNAi or treatment with the inhibitor attenuated cortactin deacetylation and actin polymerization without affecting myosin activation. Furthermore, expression of a charge-neutralizing cortactin mutant inhibited contraction and actin dynamics during contractile activation. These results suggest a novel mechanism for the regulation of smooth muscle contraction. In response to contractile stimulation, HDAC8 may mediate cortactin deacetylation, which subsequently promotes actin filament polymerization and smooth muscle contraction.

  18. Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling.

    PubMed

    Miller, Eileen; Czopek, Alicja; Duthie, Karolina M; Kirkby, Nicholas S; van de Putte, Elisabeth E Fransen; Christen, Sibylle; Kimmitt, Robert A; Moorhouse, Rebecca; Castellan, Raphael F P; Kotelevtsev, Yuri V; Kuc, Rhoda E; Davenport, Anthony P; Dhaun, Neeraj; Webb, David J; Hadoke, Patrick W F

    2017-02-01

    The role of smooth muscle endothelinB (ETB) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ETB receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ETB receptors were selectively deleted from smooth muscle by crossing floxed ETB mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ETB deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ETB was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ETB-mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ETB-mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ETB knockout compared with controls (+4.2±0.2 mm Hg; P<0.0001), but salt-induced and ETB blockade-mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ETB-mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ETB knockout mice. In the absence of other pathology, ETB receptors in vascular smooth muscle make a small but significant contribution to ETB-dependent regulation of BP. These ETB receptors have no effect on vascular contraction or neointimal remodeling.

  19. Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling

    PubMed Central

    Miller, Eileen; Czopek, Alicja; Duthie, Karolina M.; Kirkby, Nicholas S.; van de Putte, Elisabeth E. Fransen; Christen, Sibylle; Kimmitt, Robert A.; Moorhouse, Rebecca; Castellan, Raphael F.P.; Kotelevtsev, Yuri V.; Kuc, Rhoda E.; Davenport, Anthony P.; Dhaun, Neeraj; Webb, David J.

    2017-01-01

    The role of smooth muscle endothelinB (ETB) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ETB receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ETB receptors were selectively deleted from smooth muscle by crossing floxed ETB mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ETB deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ETB was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ETB-mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ETB-mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ETB knockout compared with controls (+4.2±0.2 mm Hg; P<0.0001), but salt-induced and ETB blockade–mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ETB-mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ETB knockout mice. In the absence of other pathology, ETB receptors in vascular smooth muscle make a small but significant contribution to ETB-dependent regulation of BP. These ETB receptors have no effect on vascular contraction or neointimal remodeling. PMID:28028193

  20. Toll-like receptor 2 activation and serum amyloid A regulate smooth muscle cell extracellular matrix

    PubMed Central

    Bishop, Christopher A.; Best, Michael; Rich, Celeste B.; Stone, Phillip J.

    2017-01-01

    Smooth muscle cells contribute to extracellular matrix remodeling during atherogenesis. De-differentiated, synthetic smooth muscle cells are involved in processes of migration, proliferation and changes in expression of extracellular matrix components, all of which contribute to loss of homeostasis accompanying atherogenesis. Elevated levels of acute phase proteins, including serum amyloid A (SAA), are associated with an increased risk for atherosclerosis. Although infection with periodontal and respiratory pathogens via activation of inflammatory cell Toll-like receptor (TLR)2 has been linked to vascular disease, little is known about smooth muscle cell TLR2 in atherosclerosis. This study addresses the role of SAA and TLR2 activation on smooth muscle cell matrix gene expression and insoluble elastin accumulation. Cultured rat aortic smooth muscle cells were treated with SAA or TLR2 agonists and the effect on expression of matrix metallopeptidase 9 (MMP9) and tropoelastin studied. SAA up-regulated MMP9 expression. Tropoelastin is an MMP9 substrate and decreased tropoelastin levels in SAA-treated cells supported the concept of extracellular matrix remodeling. Interestingly, SAA-induced down-regulation of tropoelastin was not only evident at the protein level but at the level of gene transcription as well. Contributions of proteasomes, nuclear factor κ B and CCAAT/enhancer binding protein β on regulation of MMP9 vs. tropoleastin expression were revealed. Effects on Mmp9 and Eln mRNA expression persisted with long-term SAA treatment, resulting in decreased insoluble elastin accumulation. Interestingly, the SAA effects were TLR2-dependent and TLR2 activation by bacterial ligands also induced MMP9 expression and decreased tropoelastin expression. These data reveal a novel mechanism whereby SAA and/or infection induce changes in vascular elastin consistent with atherosclerosis. PMID:28257481

  1. Mitochondrial regulation of cytosolic Ca²⁺ signals in smooth muscle.

    PubMed

    McCarron, John G; Olson, Marnie L; Chalmers, Susan

    2012-07-01

    The cytosolic Ca²⁺ concentration ([Ca²⁺]c) controls virtually every activity of smooth muscle, including contraction, migration, transcription, division and apoptosis. These processes may be activated by large (>10 μM) amplitude [Ca²⁺]c increases, which occur in small restricted regions of the cell or by smaller (<1 μM) amplitude changes throughout the bulk cytoplasm. Mitochondria contribute to the regulation of these signals by taking up Ca²⁺. However, mitochondria's reported low affinity for Ca²⁺ is thought to require the organelle to be positioned close to ion channels and within a microdomain of high [Ca²⁺]. In cultured smooth muscle, mitochondria are highly dynamic structures but in native smooth muscle mitochondria are immobile, apparently strategically positioned organelles that regulate the upstroke and amplitude of IP₃-evoked Ca²⁺ signals and IP₃ receptor (IP₃R) cluster activity. These observations suggest mitochondria are positioned within the high [Ca²⁺] microdomain arising from an IP₃R cluster to exert significant local control of channel activity. On the other hand, neither the upstroke nor amplitude of voltage-dependent Ca²⁺ entry is modulated by mitochondria; rather, it is the declining phase of the transient that is regulated by the organelle. Control of the declining phase of the transient requires a high mitochondrial affinity for Ca²⁺ to enable uptake to occur over the normal physiological Ca²⁺ range (<1 μM). Thus, in smooth muscle, mitochondria regulate Ca²⁺ signals exerting effects over a large range of [Ca²⁺] (∼200 nM to at least tens of micromolar) to provide a wide dynamic range in the control of Ca²⁺ signals.

  2. Substance P Responsiveness of Smooth Muscle Cells is Regulated by the Integrin Ligand, Thrombospondin

    NASA Astrophysics Data System (ADS)

    Dahm, Lisa M.; Bowers, Chauncey W.

    1996-02-01

    The extracellular factors that determine a cell's responsiveness to neurotransmitters are of particular relevance for pharmacologically diverse cell types such as neurons and smooth muscle. We previously demonstrated that matrix-associated factors are capable of dramatically and specifically suppressing the responsiveness of smooth muscle to the neuropeptide, substance P. We now demonstrate that this influence of extracellular matrix on the pharmacological phenotype of smooth muscle cells can be blocked specifically by an Arg-Gly-Asp (RGD)-containing antagonist of integrins. Of a battery of integrin ligands tested, only thrombospondin mimicked the effect of the extracellular matrix on substance P responsiveness. This effect of thrombospondin was dose dependent, RGD sensitive, and blocked by an antibody directed against the RGD-containing region of thrombospondin. Because the mRNA for thrombospondin is present in the cells of the chicken amnion, this extracellular factor may normally suppress substance P responsiveness in amniotic smooth muscle. The results suggest a role for matrix-associated integrin ligands in the regulation of cellular responses to specific neurotransmitters and hormones and in the development and maintenance of tissue-specific pharmacological properties.

  3. Arp5 is a key regulator of myocardin in smooth muscle cells

    PubMed Central

    Hayashi, Ken’ichiro

    2014-01-01

    Myocardin (Myocd) and Myocd-related transcription factors (MRTFs) are robust coactivators of serum response factor (SRF). RPEL motifs are monomeric globular actin (G-actin) binding elements that regulate MRTF localization and activity. However, the function of the RPEL motif in Myocd is largely unknown because of its low affinity for G-actin. Here, we demonstrated that the Myocd RPEL motif bound to actin-related protein 5 (Arp5) instead of conventional actin, resulting in a significant suppression of Myocd activity. In addition, Arp5 bound to a DNA binding domain of SRF via its C-terminal sequence and prevented the association of the Myocd–SRF complex with the promoter regions of smooth muscle genes. Well-differentiated smooth muscle cells mainly expressed a specific splicing variant of arp5; therefore, the protein level of Arp5 was markedly reduced by partial messenger RNA decay and translational suppression. In dedifferentiated smooth muscle cells, Arp5 knockdown restored the differentiated phenotype via Myocd activation. Thus, Arp5 is a key regulator of Myocd activity. PMID:24567363

  4. Opiorphin is a master regulator of the hypoxic response in corporal smooth muscle cells

    PubMed Central

    Fu, Shibo; Tar, Moses Tarndie; Melman, Arnold; Davies, Kelvin Paul

    2014-01-01

    Men with sickle cell disease (SCD) risk developing priapism. Recognizing that SCD is a disease of hypoxia, we investigated the effect of hypoxia on gene expression in corporal smooth muscle (CSM) cells. Rat CSM cells in vitro were treated with CoCl2 or low oxygen tension to mimic hypoxia. Hypoxic conditions increased expression of genes previously associated with priapism in animal models. Variable coding sequence a1 (Vcsa1; the rat opiorphin homologue, sialorphin), hypoxia-inducible factor 1a (Hif-1a), and A2B adenosine receptor (a2br) were increased by 10-, 4-, and 6-fold, respectively, by treatment with CoCl2, whereas low oxygen tension caused increases in expression of 3-, 4-, and 1.5-fold, respectively. Sialorphin-treated CSM cells increased expression of Hif-1a and a2br by 4-fold, and vcsa1-siRNA treatment reduced expression by ∼50%. Using a Hif-1a inhibitor, we demonstrated up-regulation of a2br by sialorphin is dependent on Hif-1a, and knockdown of vcsa1 expression with vcsa1-siRNA demonstrated that hypoxic-up-regulation of Hif-1a is dependent on vcsa1. In CSM from a SCD mouse, there was 15-fold up-regulation of opiorphin at a life stage prior to priapism. We conclude that in CSM, opiorphins are master regulators of the hypoxic response. Opiorphin up-regulation in response to SCD-associated hypoxia activates CSM “relaxant” pathways; excessive activation of these pathways results in priapism.—Fu, S., Tar, M. T., Melman, A., Davies, K. P. Opiorphin is a master regulator of the hypoxic response in corporal smooth muscle cells. PMID:24803544

  5. Procontractile G protein–mediated signaling pathways antagonistically regulate smooth muscle differentiation in vascular remodeling

    PubMed Central

    Althoff, Till F.; Juárez, Julián Albarrán; Troidl, Kerstin; Tang, Cong; Wang, Shengpeng; Wirth, Angela; Takefuji, Mikito; Wettschureck, Nina

    2012-01-01

    Vascular smooth muscle (Sm) cells (VSMCs) are highly plastic. Their differentiation state can be regulated by serum response factor (SRF), which activates genes involved in Sm differentiation and proliferation by recruiting cofactors, such as members of the myocardin family and ternary complex factors (TCFs), respectively. However, the extracellular cues and upstream signaling mechanisms regulating SRF-dependent VSMC differentiation under in vivo conditions are poorly understood. In this study, we show that the procontractile signaling pathways mediated by the G proteins G12/G13 and Gq/G11 antagonistically regulate VSMC plasticity in different models of vascular remodeling. In mice lacking Gα12/Gα13 or their effector, the RhoGEF protein LARG, RhoA-dependent SRF-regulation was blocked and down-regulation of VSMC differentiation marker genes was enhanced. This was accompanied by an excessive vascular remodeling and exacerbation of atherosclerosis. In contrast, Sm-specific Gαq/Gα11 deficiency blocked activation of extracellular signal-regulated kinase 1/2 and the TCF Elk-1, resulting in a reduced VSMC dedifferentiation in response to flow cessation or vascular injury. These data show that the balanced activity of both G protein–mediated pathways in VSMCs is required for an appropriate vessel remodeling response in vascular diseases and suggest new approaches to modulate Sm differentiation in vascular pathologies. PMID:23129751

  6. Activated mineralocorticoid receptor regulates micro-RNA-29b in vascular smooth muscle cells.

    PubMed

    Bretschneider, Maria; Busch, Bianca; Mueller, Daniel; Nolze, Alexander; Schreier, Barbara; Gekle, Michael; Grossmann, Claudia

    2016-04-01

    Inappropriately activated mineralocorticoid receptor (MR) is a risk factor for vascular remodeling with unclear molecular mechanism. Recent findings suggest that post-transcriptional regulation by micro-RNAs (miRs) may be involved. Our aim was to search for MR-dependent miRs in vascular smooth muscle cells (VSMCs) and to explore the underlying molecular mechanism and the pathologic relevance. We detected that aldosteroneviathe MR reduces miR-29bin vivoin murine aorta and in human primary and cultured VSMCs (ED50= 0.07 nM) but not in endothelial cells [quantitative PCR (qPCR), luciferase assays]. This effect was mediated by an increased decay of miR-29b in the cytoplasm with unchanged miR-29 family member or primary-miR levels. Decreased miR-29b led to an increase in extracellular matrix measured by ELISA and qPCR and enhanced VSMC migration in single cell-tracking experiments. Additionally, cell proliferation and the apoptosis/necrosis ratio (caspase/lactate dehydrogenase assay) was modulated by miR-29b. Enhanced VSMC migration by aldosterone required miR-29b regulation. Control experiments were performed with scrambled RNA and empty plasmids, by comparing aldosterone-stimulated with vehicle-incubated cells. Overall, our findings provide novel insights into the molecular mechanism of aldosterone-mediated vascular pathogenesis by identifying miR-29b as a pathophysiologic relevant target of activated MR in VSMCs and by highlighting the importance of miR processing for miR regulation.-Bretschneider, M., Busch, B., Mueller, D., Nolze, A., Schreier, B., Gekle, M., Grossmann, C. Activated mineralocorticoid receptor regulates micro-RNA-29b in vascular smooth muscle cells.

  7. A novel role for RhoA GTPase in the regulation of airway smooth muscle contraction.

    PubMed

    Zhang, Wenwu; Huang, Youliang; Wu, Yidi; Gunst, Susan J

    2015-02-01

    Recent studies have demonstrated a novel molecular mechanism for the regulation of airway smooth muscle (ASM) contraction by RhoA GTPase. In ASM tissues, both myosin light chain (MLC) phosphorylation and actin polymerization are required for active tension generation. RhoA inactivation dramatically suppresses agonist-induced tension development and completely inhibits agonist-induced actin polymerization, but only slightly reduces MLC phosphorylation. The inhibition of MLC phosphatase does not reverse the effects of RhoA inactivation on contraction or actin polymerization. Thus, RhoA regulates ASM contraction through its effects on actin polymerization rather than MLC phosphorylation. Contractile stimulation of ASM induces the recruitment and assembly of paxillin, vinculin, and focal adhesion kinase (FAK) into membrane adhesion complexes (adhesomes) that regulate actin polymerization by catalyzing the activation of cdc42 GTPase by the G-protein-coupled receptor kinase-interacting target (GIT) - p21-activated kinase (PAK) - PAK-interacting exchange factor (PIX) complex. Cdc42 is a necessary and specific activator of the actin filament nucleation activator, N-WASp. The recruitment and activation of paxillin, vinculin, and FAK is prevented by RhoA inactivation, thus preventing cdc42 and N-WASp activation. We conclude that RhoA regulates ASM contraction by catalyzing the assembly and activation of membrane adhesome signaling modules that regulate actin polymerization, and that the RhoA-mediated assembly of adhesome complexes is a fundamental step in the signal transduction process in response to a contractile agonist.

  8. TSHZ3 and SOX9 Regulate the Timing of Smooth Muscle Cell Differentiation in the Ureter by Reducing Myocardin Activity

    PubMed Central

    Martin, Elise; Caubit, Xavier; Airik, Rannar; Vola, Christine; Fatmi, Ahmed; Kispert, Andreas; Fasano, Laurent

    2013-01-01

    Smooth muscle cells are of key importance for the proper functioning of different visceral organs including those of the urogenital system. In the mouse ureter, the two transcriptional regulators TSHZ3 and SOX9 are independently required for initiation of smooth muscle differentiation from uncommitted mesenchymal precursor cells. However, it has remained unclear whether TSHZ3 and SOX9 act independently or as part of a larger regulatory network. Here, we set out to characterize the molecular function of TSHZ3 in the differentiation of the ureteric mesenchyme. Using a yeast-two-hybrid screen, we identified SOX9 as an interacting protein. We show that TSHZ3 also binds to the master regulator of the smooth muscle program, MYOCD, and displaces it from the coregulator SRF, thereby disrupting the activation of smooth muscle specific genes. We found that the initiation of the expression of smooth muscle specific genes in MYOCD-positive ureteric mesenchyme coincides with the down regulation of Sox9 expression, identifying SOX9 as a possible negative regulator of smooth muscle cell differentiation. To test this hypothesis, we prolonged the expression of Sox9 in the ureteric mesenchyme in vivo. We found that Sox9 does not affect Myocd expression but significantly reduces the expression of MYOCD/SRF-dependent smooth muscle genes, suggesting that down-regulation of Sox9 is a prerequisite for MYOCD activity. We propose that the dynamic expression of Sox9 and the interaction between TSHZ3, SOX9 and MYOCD provide a mechanism that regulates the pace of progression of the myogenic program in the ureter. PMID:23671695

  9. Functional up-regulation of KCNA gene family expression in murine mesenteric resistance artery smooth muscle

    PubMed Central

    Fountain, S J; Cheong, A; Flemming, R; Mair, L; Sivaprasadarao, A; Beech, D J

    2004-01-01

    This study focused on the hypothesis that KCNA genes (which encode KVα1 voltage-gated K+ channels) have enhanced functional expression in smooth muscle cells of a primary determinant of peripheral resistance – the small mesenteric artery. Real-time PCR methodology was developed to measure cell type-specific in situ gene expression. Profiles were determined for arterial myocyte expression of RNA species encoding KVα1 subunits as well as KVβ1, KVα2.1, KVγ9.3, BKCaα1 and BKCaβ1. The seven major KCNA genes were expressed and more readily detected in endothelium-denuded mesenteric resistance artery compared with thoracic aorta; quantification revealed dramatic differential expression of one to two orders of magnitude. There was also four times more RNA encoding KVα2.1 but less or similar amounts encoding KVβ1, KVγ9.3, BKCaα1 and BKCaβ1. Patch-clamp recordings from freshly isolated smooth muscle cells revealed dominant KVα1 K+ current and current density twice as large in mesenteric cells. Therefore, we suggest the increased RNA production of the resistance artery impacts on physiological function, although there is quantitatively less K+ current than might be expected. The mechanism conferring up-regulated expression of KCNA genes may be common to all the gene family and play a functional role in the physiological control of blood pressure. PMID:14742730

  10. Ion channel regulation of intracellular calcium and airway smooth muscle function.

    PubMed

    Perez-Zoghbi, Jose F; Karner, Charlotta; Ito, Satoru; Shepherd, Malcolm; Alrashdan, Yazan; Sanderson, Michael J

    2009-10-01

    Airway hyper-responsiveness associated with asthma is mediated by airway smooth muscle cells (SMCs) and has a complicated etiology involving increases in cell contraction and proliferation and the secretion of inflammatory mediators. Although these pathological changes are diverse, a common feature associated with their regulation is a change in intracellular Ca(2+) concentration ([Ca(2+)](i)). Because the [Ca(2+)](i) itself is a function of the activity and expression of a variety of ion channels, in both the plasma membrane and sarcoplasmic reticulum of the SMC, the modification of this ion channel activity may predispose airway SMCs to hyper-responsiveness. Our objective is to review how ion channels determine the [Ca(2+)](i) and influence the function of airway SMCs and emphasize the potential of ion channels as sites for therapeutic approaches to asthma.

  11. Function and regulation of large conductance Ca(2+)-activated K+ channel in vascular smooth muscle cells.

    PubMed

    Hu, Xiang-Qun; Zhang, Lubo

    2012-09-01

    Large conductance Ca(2+)-activated K(+) (BK(Ca)) channels are abundantly expressed in vascular smooth muscle cells. Activation of BK(Ca) channels leads to hyperpolarization of cell membrane, which in turn counteracts vasoconstriction. Therefore, BK(Ca) channels have an important role in regulation of vascular tone and blood pressure. The activity of BK(Ca) channels is subject to modulation by various factors. Furthermore, the function of BK(Ca) channels are altered in both physiological and pathophysiological conditions, such as pregnancy, hypertension and diabetes, which has dramatic impacts on vascular tone and hemodynamics. Consequently, compounds and genetic manipulation that alter activity and expression of the channel might be of therapeutic interest.

  12. The SWI/SNF chromatin remodeling complex regulates myocardin-induced smooth muscle-specific gene expression

    PubMed Central

    Zhou, Jiliang; Zhang, Min; Fang, Hong; El-Mounayri, Omar; Rodenberg, Jennifer M.; Imbalzano, Anthony N.; Herring, B. Paul

    2009-01-01

    Objective Transcription regulatory complexes comprising myocardin and serum response factor (SRF) are critical for the transcriptional regulation of many smooth muscle-specific genes. However, little is known about the epigenetic mechanisms that regulate the activity of these complexes. In the current study, we investigated the role of SWI/SNF ATP-dependent chromatin remodeling enzymes in regulating the myogenic activity of myocardin. Methods and Results We found that both Brg1 and Brm are required for maintaining expression of several smooth muscle-specific genes in primary cultures of aortic smooth muscle cells. Furthermore, the ability of myocardin to induce expression of smooth muscle-specific genes is abrogated in cells expressing dominant negative Brg1. In SW13 cells, that lack endogenous Brg1 and Brm1, myocardin is unable to induce expression of smooth muscle-specific genes. Whereas, reconstitution of wild type, or bromodomain mutant forms Brg1 or Brm1, into SW13 cells restored their responsiveness to myocardin. SWI/SNF complexes were found to be required for myocardin to increase SRF binding to the promoters of smooth muscle-specific genes. Brg1 and Brm directly bind to the N-terminus of myocardin, in vitro, through their ATPase domains and Brg1 forms a complex with SRF and myocardin in vivo in smooth muscle cells. Conclusion These data demonstrate that the ability of myocardin to induce smooth muscle-specific gene expression is dependent on its interaction with SWI/SNF ATP-dependent chromatin remodeling complexes. PMID:19342595

  13. Opiorphin is a master regulator of the hypoxic response in corporal smooth muscle cells.

    PubMed

    Fu, Shibo; Tar, Moses Tarndie; Melman, Arnold; Davies, Kelvin Paul

    2014-08-01

    Men with sickle cell disease (SCD) risk developing priapism. Recognizing that SCD is a disease of hypoxia, we investigated the effect of hypoxia on gene expression in corporal smooth muscle (CSM) cells. Rat CSM cells in vitro were treated with CoCl2 or low oxygen tension to mimic hypoxia. Hypoxic conditions increased expression of genes previously associated with priapism in animal models. Variable coding sequence a1 (Vcsa1; the rat opiorphin homologue, sialorphin), hypoxia-inducible factor 1a (Hif-1a), and A2B adenosine receptor (a2br) were increased by 10-, 4-, and 6-fold, respectively, by treatment with CoCl2, whereas low oxygen tension caused increases in expression of 3-, 4-, and 1.5-fold, respectively. Sialorphin-treated CSM cells increased expression of Hif-1a and a2br by 4-fold, and vcsa1-siRNA treatment reduced expression by ∼50%. Using a Hif-1a inhibitor, we demonstrated up-regulation of a2br by sialorphin is dependent on Hif-1a, and knockdown of vcsa1 expression with vcsa1-siRNA demonstrated that hypoxic-up-regulation of Hif-1a is dependent on vcsa1. In CSM from a SCD mouse, there was 15-fold up-regulation of opiorphin at a life stage prior to priapism. We conclude that in CSM, opiorphins are master regulators of the hypoxic response. Opiorphin up-regulation in response to SCD-associated hypoxia activates CSM "relaxant" pathways; excessive activation of these pathways results in priapism.

  14. MicroRNA-143-3p inhibits hyperplastic scar formation by targeting connective tissue growth factor CTGF/CCN2 via the Akt/mTOR pathway.

    PubMed

    Mu, Shengzhi; Kang, Bei; Zeng, Weihui; Sun, Yaowen; Yang, Fan

    2016-05-01

    Post-traumatic hypertrophic scar (HS) is a fibrotic disease with excessive extracellular matrix (ECM) production, which is a response to tissue injury by fibroblasts. Although emerging evidence has indicated that miRNA contributes to hypertrophic scarring, the role of miRNA in HS formation remains unclear. In this study, we found that miR-143-3p was markedly downregulated in HS tissues and fibroblasts (HSFs) using qRT-PCR. The expression of connective tissue growth factor (CTGF/CCN2) was upregulated both in HS tissues and HSFs, which is proposed to play a key role in ECM deposition in HS. The protein expression of collagen I (Col I), collagen III (Col III), and α-smooth muscle actin (α-SMA) was obviously inhibited after treatment with miR-143-3p in HSFs. The CCK-8 assay showed that miR-143-3p transfection reduced the proliferation ability of HSFs, and flow cytometry showed that either early or late apoptosis of HSFs was upregulated by miR-143-3p. In addition, the activity of caspase 3 and caspase 9 was increased after miR-143-3p transfection. On the contrary, the miR-143-3p inhibitor was demonstrated to increase cell proliferation and inhibit apoptosis of HSFs. Moreover, miR-143-3p targeted the 3'-UTR of CTGF and caused a significant decrease of CTGF. Western blot demonstrated that Akt/mTOR phosphorylation and the expression of CTGF, Col I, Col III, and α-SMA were inhibited by miR-143-3p, but increased by CTGF overexpression. In conclusion, we found that miR-143-3p inhibits hypertrophic scarring by regulating the proliferation and apoptosis of human HSFs, inhibiting ECM production-associated protein expression by targeting CTGF, and restraining the Akt/mTOR pathway.

  15. Smoothing out transitions: how pedagogy influences medical students' achievement of self-regulated learning goals.

    PubMed

    White, Casey B

    2007-08-01

    Medical school is an academic and developmental path toward a professional life demanding self-regulation and self-education. Thus, many medical schools include in their goals for medical student education their graduates' ability to self-assess and self-regulate their education upon graduation and throughout their professional lives. This study explores links between medical students' use of self-regulated learning as it relates to motivation, autonomy, and control, and how these influenced their experiences in medical school. Subjects were medical students in two distinct medical school environments, "Problem-based learning" and "Traditional." PBL students described a rough transition into medical school, but once they felt comfortable with the autonomy and control PBL gave them, they embraced the independence and responsibility. They found themselves motivated to learning for learning's sake, and able to channel their motivation into effective transitions from the classrooms into the clerkships. Traditional students had a rougher transition from the classrooms to the clerkships. In the first two years they relied on faculty to direct and control learning, and they channeled their motivation toward achieving the highest grade. In the clerkships, they found faculty expected them to be more independent and self-directed than they felt prepared to be, and they struggled to assume responsibility for their learning. Self-regulated learning can help smooth out the transitions through medical school by preparing first and second year students for expectations in the third and fourth years, which can then maximize learning in the clinical milieu, and prepare medical students for a lifetime of learning.

  16. Rab5a-mediated autophagy regulates the phenotype and behavior of vascular smooth muscle cells

    PubMed Central

    Tan, Jin-Yun; Jia, Luo-Qi; Shi, Wei-Hao; He, Qing; Zhu, Lei; Yu, Bo

    2016-01-01

    Rab5a, a key member of the Rab family of GTPases, was determined to be a regulator of vascular smooth muscle cell (VSMC) proliferation and migration. However, the exact regulatory mechanism remains unclear. As Rab5a has been shown to be associated with autophagy, which is essential for the conversion of VSMCs from a contractile to a synthetic phenotype in order to prevent cell death due to oxidative stress. The present study hypothesized that autophagy may be responsible for the proliferation and migration of VSMCs via the Rab5a protein. The aim of the present study was to evaluate the effect of Rab5a on autophagy in VSMCs. The human aorta vascular smooth muscle cell line, T/G HA-VSMCs, was treated with small interfering (si)RNA against Rab5a and/or platelet-derived growth factor (PDGF). Following treatment, the phenotype transition of the VSMCs was evaluated by detecting the mRNA and protien expression levels of VSMC molecular markers using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. In addition, autophagy in VSMCs was evaluated by western blotting for autophagy-associated proteins, flow cytometry of acidic vesicular organelles, punctate fluorescence of microtubule associated protein light chain 3 and transmission electron microscopy of typical scattered double-membrane vacuolar structures. Additionally, the proliferation, migration, cell cycle and apoptotic response of VSMCs were detected by sulforhodamine B assay, transwell assay and flow cytometry, respectively. The results revealed that transfection with siRNA against Rab5a led to a significant decrease in Rab5a protein expression, while the reduced expression trend of Rab5a was rescued by intervention with PDGF. Furthermore, cells transfected with siRNA against Rab5a inhibited the autophagy of VSMCs. Downregulated Rab5a inhibited the phenotype transition of VSMCs. Additionally, downregulated Rab5a led to slowed cell growth, decreased numbers of migrated

  17. Regulation of ERK5 by insulin and angiotensin-II in vascular smooth muscle cells

    SciTech Connect

    Sharma, Girish; Goalstone, Marc Lee; E-mail: Marc.Goalstone@uchsc.edu

    2007-03-23

    ERK5 is involved in proliferation of vascular smooth muscle cells (VSMC). The proliferative actions of insulin and angiotensin-II (A-II) in VSMC are mediated in part by ERK1/2. We hypothesized that insulin and A-II also regulate ERK5 activity in VSMC. Acute treatment (<60 min) with insulin or A-II increased phosphorylation of ERK1/2 at 15 min and ERK5 at 5 min. Chronic treatment ({<=}8 h) with insulin increased ERK1/2 phosphorylation by 4 h and ERK5 by 8 h. A-II-stimulated phosphorylation of ERK1/2 by 8 h and ERK5 by 4 h. The EC{sub 50} for insulin treatment effecting ERK1/2 and ERK5 phosphorylation was 1.5 and 0.1 nM, whereas the EC{sub 50} for A-II was 2 nM, each. Insulin plus A-II induced an additive effect only on ERK5 phosphorylation. Inhibition of insulin- and A-II-stimulated phosphorylation of ERK5 and ERK1/2 by PD98059 and Wortmannin exhibited differential and time-dependent effects. Taken together, these data indicate that insulin and A-II regulate the activity of ERK5, but different from that seen for ERK1/2.

  18. Regulation of SIRT1 in vascular smooth muscle cells from streptozotocin-diabetic rats.

    PubMed

    Toniolo, Alice; Warden, Erica Alessia; Nassi, Alberto; Cignarella, Andrea; Bolego, Chiara

    2013-01-01

    Sirtuins enzymes are a conserved family of nicotinamide adenine dinucleotide (NAD)-dependent deacetylases and ADP-ribosyltransferases that mediate responses to oxidative stress, fasting and dietary restriction in mammals. Vascular smooth muscle cells (VSMCs) are involved in many mechanisms that regulate vascular biology in vivo but the role of SIRT1 has not been explored in much detail. Therefore, we investigated the regulation of SIRT1 in cultured VSMCs under various stress conditions including diabetes. Sprague-Dawley rats were made diabetic by injecting a single dose of streptozotocin (65 mg/Kg), and aortic VSMCs were isolated after 4 weeks. Immunocytochemistry showed that SIRT1 was localized predominantly in the nucleus, with lower staining in VSMCs from STZ-diabetic as compared with normoglycemic rats. Previous diabetes induction in vivo and high glucose concentrations in vitro significantly downregulated SIRT1 amounts as detected in Western blot assays, whereas TNF-α (30 ng/ml) stimulation failed to induce significant changes. Because estrogen signaling affects several pathways of oxidative stress control, we also investigated SIRT1 modulation by 17β-estradiol. Treatment with the hormone (10 nM) or a selective estrogen receptor-α agonist decreased SIRT1 levels in VSMCs from normoglycemic but not in those from STZ-diabetic animals. 17β-estradiol treatment also enhanced activation of AMP-dependent kinase, which partners with SIRT1 in a signaling axis. SIRT1 downregulation by 17β-estradiol could be observed as well in human peripheral blood mononuclear cells, a cell type in which SIRT1 downregulation is associated with insulin resistance and subclinical atherosclerosis. These data suggest that SIRT1 protein levels are regulated by diverse cellular stressors to a variable extent in VSMCs from diabetic and normoglycemic rats, warranting further investigation on SIRT1 as a modulator of VSMC activity in settings of vascular inflammation.

  19. Phosphodiesterases Regulate BAY 41-2272-Induced VASP Phosphorylation in Vascular Smooth Muscle Cells

    PubMed Central

    Adderley, Shaquria P.; Joshi, Chintamani N.; Martin, Danielle N.; Tulis, David Anthony

    2012-01-01

    BAY 41-2272 (BAY), a stimulator of soluble guanylyl cyclase, increases cyclic nucleotides and inhibits proliferation of vascular smooth muscle cells (VSMCs). In this study, we elucidated mechanisms of action of BAY in its regulation of vasodilator-stimulated phosphoprotein (VASP) with an emphasis on VSMC phosphodiesterases (PDEs). BAY alone increased phosphorylation of VASPSer239 and VASPSer157, respective indicators of PKG and PKA signaling. IBMX, a non-selective inhibitor of PDEs, had no effect on BAY-induced phosphorylation at VASPSer239 but inhibited phosphorylation at VASPSer157. Selective inhibitors of PDE3 or PDE4 attenuated BAY-mediated increases at VASPSer239 and VASPSer157, whereas PDE5 inhibition potentiated BAY-mediated increases only at VASPSer157. In comparison, 8Br-cGMP increased phosphorylation at VASPSer239 and VASPSer157 which were not affected by selective PDE inhibitors. In the presence of 8Br-cAMP, inhibition of either PDE4 or PDE5 decreased VASPSer239 phosphorylation and inhibition of PDE3 increased phosphorylation at VASPSer239, while inhibition of PDE3 or PDE4 increased and PDE5 inhibition had no effect on VASPSer157 phosphorylation. These findings demonstrate that BAY operates via cAMP and cGMP along with regulation by PDEs to phosphorylate VASP in VSMCs and that the mechanism of action of BAY in VSMCs is different from that of direct cyclic nucleotide analogs with respect to VASP phosphorylation and the involvement of PDEs. Given a role for VASP as a critical cytoskeletal protein, these findings provide evidence for BAY as a regulator of VSMC growth and a potential therapeutic agent against vasculoproliferative disorders. PMID:22347188

  20. TRPC3 regulates release of brain-derived neurotrophic factor from human airway smooth muscle.

    PubMed

    Vohra, Pawan K; Thompson, Michael A; Sathish, Venkatachalem; Kiel, Alexander; Jerde, Calvin; Pabelick, Christina M; Singh, Brij B; Prakash, Y S

    2013-12-01

    Exogenous brain-derived neurotrophic factor (BDNF) enhances Ca(2+) signaling and cell proliferation in human airway smooth muscle (ASM), especially with inflammation. Human ASM also expresses BDNF, raising the potential for autocrine/paracrine effects. The mechanisms by which ASM BDNF secretion occurs are not known. Transient receptor potential channels (TRPCs) regulate a variety of intracellular processes including store-operated Ca(2+) entry (SOCE; including in ASM) and secretion of factors such as cytokines. In human ASM, we tested the hypothesis that TRPC3 regulates BDNF secretion. At baseline, intracellular BDNF was present, and BDNF secretion was detectable by enzyme linked immunosorbent assay (ELISA) of cell supernatants or by real-time fluorescence imaging of cells transfected with GFP-BDNF vector. Exposure to the pro-inflammatory cytokine tumor necrosis factor-alpha (TNFα) (20ng/ml, 48h) or a mixture of allergens (ovalbumin, house dust mite, Alternaria, and Aspergillus extracts) significantly enhanced BDNF secretion and increased TRPC3 expression. TRPC3 knockdown (siRNA or inhibitor Pyr3; 10μM) blunted BDNF secretion, and prevented inflammation effects. Chelation of extracellular Ca(2+) (EGTA; 1mM) or intracellular Ca(2+) (BAPTA; 5μM) significantly reduced secreted BDNF, as did the knockdown of SOCE proteins STIM1 and Orai1 or plasma membrane caveolin-1. Functionally, secreted BDNF had autocrine effects suggested by phosphorylation of high-affinity tropomyosin-related kinase TrkB receptor, prevented by chelating extracellular BDNF with chimeric TrkB-Fc. These data emphasize the role of TRPC3 and Ca(2+) influx in the regulation of BDNF secretion by human ASM and the enhancing effects of inflammation. Given the BDNF effects on Ca(2+) and cell proliferation, BDNF secretion may contribute to altered airway structure and function in diseases such as asthma.

  1. Biphasic regulation of myosin light chain phosphorylation by p21-activated kinase modulates intestinal smooth muscle contractility.

    PubMed

    Chu, Ji; Pham, Ngoc T; Olate, Nicole; Kislitsyna, Karina; Day, Mary-Clare; LeTourneau, Phillip A; Kots, Alexander; Stewart, Randolph H; Laine, Glen A; Cox, Charles S; Uray, Karen

    2013-01-11

    Supraphysiological mechanical stretching in smooth muscle results in decreased contractile activity. However, the mechanism is unclear. Previous studies indicated that intestinal motility dysfunction after edema development is associated with increased smooth muscle stress and decreased myosin light chain (MLC) phosphorylation in vivo, providing an ideal model for studying mechanical stress-mediated decrease in smooth muscle contraction. Primary human intestinal smooth muscle cells (hISMCs) were subjected to either control cyclical stretch (CCS) or edema (increasing) cyclical stretch (ECS), mimicking the biophysical forces in non-edematous and edematous intestinal smooth muscle in vivo. ECS induced significant decreases in phosphorylation of MLC and MLC phosphatase targeting subunit (MYPT1) and a significant increase in p21-activated kinase (PAK) activity compared with CCS. PAK regulated MLC phosphorylation in an activity-dependent biphasic manner. PAK activation increased MLC and MYPT1 phosphorylation in CCS but decreased MLC and MYPT1 phosphorylation in hISMCs subjected to ECS. PAK inhibition had the opposite results. siRNA studies showed that PAK1 plays a critical role in regulating MLC phosphorylation in hISMCs. PAK1 enhanced MLC phosphorylation via phosphorylating MYPT1 on Thr-696, whereas PAK1 inhibited MLC phosphorylation via decreasing MYPT1 on both Thr-696 and Thr-853. Importantly, in vivo data indicated that PAK activity increased in edematous tissue, and inhibition of PAK in edematous intestine improved intestinal motility. We conclude that PAK1 positively regulates MLC phosphorylation in intestinal smooth muscle through increasing inhibitory phosphorylation of MYPT1 under physiologic conditions, whereas PAK1 negatively regulates MLC phosphorylation via inhibiting MYPT1 phosphorylation when PAK activity is increased under pathologic conditions.

  2. Aging impairs smooth muscle-mediated regulation of aortic stiffness: a defect in shock absorption function?

    PubMed

    Gao, Yuan Z; Saphirstein, Robert J; Yamin, Rina; Suki, Bela; Morgan, Kathleen G

    2014-10-15

    Increased aortic stiffness is an early and independent biomarker of cardiovascular disease. Here we tested the hypothesis that vascular smooth muscle cells (VSMCs) contribute significantly to aortic stiffness and investigated the mechanisms involved. The relative contributions of VSMCs, focal adhesions (FAs), and matrix to stiffness in mouse aorta preparations at optimal length and with confirmed VSMC viability were separated by the use of small-molecule inhibitors and activators. Using biomechanical methods designed for minimal perturbation of cellular function, we directly quantified changes with aging in aortic material stiffness. An alpha adrenoceptor agonist, in the presence of N(G)-nitro-l-arginine methyl ester (l-NAME) to remove interference of endothelial nitric oxide, increases stiffness by 90-200% from baseline in both young and old mice. Interestingly, increases are robustly suppressed by the Src kinase inhibitor PP2 in young but not old mice. Phosphotyrosine screening revealed, with aging, a biochemical signature of markedly impaired agonist-induced FA remodeling previously associated with Src signaling. Protein expression measurement confirmed a decrease in Src expression with aging. Thus we report here an additive model for the in vitro biomechanical components of the mouse aortic wall in which 1) VSMCs are a surprisingly large component of aortic stiffness at physiological lengths and 2) regulation of the VSMC component through FA signaling and hence plasticity is impaired with aging, diminishing the aorta's normal shock absorption function in response to stressors.

  3. Aging impairs smooth muscle-mediated regulation of aortic stiffness: a defect in shock absorption function?

    PubMed Central

    Gao, Yuan Z.; Saphirstein, Robert J.; Yamin, Rina; Suki, Bela

    2014-01-01

    Increased aortic stiffness is an early and independent biomarker of cardiovascular disease. Here we tested the hypothesis that vascular smooth muscle cells (VSMCs) contribute significantly to aortic stiffness and investigated the mechanisms involved. The relative contributions of VSMCs, focal adhesions (FAs), and matrix to stiffness in mouse aorta preparations at optimal length and with confirmed VSMC viability were separated by the use of small-molecule inhibitors and activators. Using biomechanical methods designed for minimal perturbation of cellular function, we directly quantified changes with aging in aortic material stiffness. An alpha adrenoceptor agonist, in the presence of NG-nitro-l-arginine methyl ester (l-NAME) to remove interference of endothelial nitric oxide, increases stiffness by 90–200% from baseline in both young and old mice. Interestingly, increases are robustly suppressed by the Src kinase inhibitor PP2 in young but not old mice. Phosphotyrosine screening revealed, with aging, a biochemical signature of markedly impaired agonist-induced FA remodeling previously associated with Src signaling. Protein expression measurement confirmed a decrease in Src expression with aging. Thus we report here an additive model for the in vitro biomechanical components of the mouse aortic wall in which 1) VSMCs are a surprisingly large component of aortic stiffness at physiological lengths and 2) regulation of the VSMC component through FA signaling and hence plasticity is impaired with aging, diminishing the aorta's normal shock absorption function in response to stressors. PMID:25128168

  4. Cyclin-dependent kinase inhibitor, p21Waf1, regulates vascular smooth muscle cell hypertrophy.

    PubMed

    Okamoto, Kenichi; Kato, Seiya; Arima, Nobuyuki; Fujii, Teruhiko; Morimatsu, Minoru; Imaizumi, Tsutomu

    2004-04-01

    In the process of vascular diseases, smooth muscle cells (SMC) undergo not only hyperplasia but also hypertrophy, resulting in vascular remodeling. A cyclin-dependent kinase inhibitor (CDKI), p21Waf1, has been shown to play an important role in SMC hyperplasia. Here we investigated a potential role of p21Waf1 in SMC hypertrophy. An exposure of cultured rat SMC to serum drove the cell cycle progression with up-regulation of various cell cycle markers and increased activities of cyclin-dependent kinases, but did not cause SMC hypertrophy. In contrast, incubation of SMC for 48 h with angiotensin II (AII, 100 nmol/l) resulted in a significant increase in the cell size measured by flowcytometric forward-angle light scatter assay, in association with an increase in the ratio of [3H]leucine/[3H]thymidine uptake, indicating SMC hypertrophy. At 48 h, p21Waf1 expression was up-regulated in SMC exposed to AII but not in those exposed to serum. These results suggest that p21Waf1 may be involved in hypertrophy. To further investigate this issue, two manipulations of the p21Waf1 gene were performed. Adenovirus-mediated over-expression of p21Waf1 not only reduced S-phasic cells but also caused hypertrophy, despite the exposure to serum. Antisense oligodeoxynucleotide for p21Waf1 inhibited the hypertrophy of SMC exposed to AII. Our data suggest that p21Waf1 may play a role in SMC hypertrophy as well.

  5. TLR4-Activated MAPK-IL-6 Axis Regulates Vascular Smooth Muscle Cell Function.

    PubMed

    Lee, Guan-Lin; Wu, Jing-Yiing; Tsai, Chien-Sung; Lin, Chih-Yuan; Tsai, Yi-Ting; Lin, Chin-Sheng; Wang, Yi-Fu; Yet, Shaw-Fang; Hsu, Yu-Juei; Kuo, Cheng-Chin

    2016-08-24

    Migration of vascular smooth muscle cells (VSMCs) into the intima is considered to be a vital event in the pathophysiology of atherosclerosis. Despite substantial evidence supporting the pathogenic role of Toll-like receptor 4 (TLR4) in the progression of atherogenesis, its function in the regulation of VSMC migration remains unclear. The goal of the present study was to elucidate the mechanism by which TLR4 regulates VSMC migration. Inhibitor experiments revealed that TLR4-induced IL-6 secretion and VSMC migration were mediated via the concerted actions of MyD88 and TRIF on the activation of p38 MAPK and ERK1/2 signaling. Neutralizing anti-IL-6 antibodies abrogated TLR4-driven VSMC migration and F-actin polymerization. Blockade of p38 MAPK or ERK1/2 signaling cascade inhibited TLR4 agonist-mediated activation of cAMP response element binding protein (CREB). Moreover, siRNA-mediated suppression of CREB production repressed TLR4-induced IL-6 production and VSMC migration. Rac-1 inhibitor suppressed TLR4-driven VSMC migration but not IL-6 production. Importantly, the serum level of IL-6 and TLR4 endogenous ligand HMGB1 was significantly higher in patients with coronary artery diseases (CAD) than in healthy subjects. Serum HMGB1 level was positively correlated with serum IL-6 level in CAD patients. The expression of both HMGB1 and IL-6 was clearly detected in the atherosclerotic tissue of the CAD patients. Additionally, there was a positive association between p-CREB and HMGB1 in mouse atherosclerotic tissue. Based on our findings, we concluded that, upon ligand binding, TLR4 activates p38 MAPK and ERK1/2 signaling through MyD88 and TRIF in VSMCs. These signaling pathways subsequently coordinate an additive augmentation of CREB-driven IL-6 production, which in turn triggers Rac-1-mediated actin cytoskeleton to promote VSMC migration.

  6. BKCa channel regulates calcium oscillations induced by alpha-2-macroglobulin in human myometrial smooth muscle cells

    PubMed Central

    Wakle-Prabagaran, Monali; Lorca, Ramón A.; Ma, Xiaofeng; Stamnes, Susan J.; Amazu, Chinwendu; Hsiao, Jordy J.; Hyrc, Krzysztof L.; Wright, Michael E.; England, Sarah K.

    2016-01-01

    The large-conductance, voltage-gated, calcium (Ca2+)-activated potassium channel (BKCa) plays an important role in regulating Ca2+ signaling and is implicated in the maintenance of uterine quiescence during pregnancy. We used immunopurification and mass spectrometry to identify proteins that interact with BKCa in myometrium samples from term pregnant (≥37 wk gestation) women. From this screen, we identified alpha-2-macroglobulin (α2M). We then used immunoprecipitation followed by immunoblot and the proximity ligation assay to confirm the interaction between BKCa and both α2M and its receptor, low-density lipoprotein receptor-related protein 1 (LRP1), in cultured primary human myometrial smooth muscle cells (hMSMCs). Single-channel electrophysiological recordings in the cell-attached configuration demonstrated that activated α2M (α2M*) increased the open probability of BKCa in an oscillatory pattern in hMSMCs. Furthermore, α2M* caused intracellular levels of Ca2+ to oscillate in oxytocin-primed hMSMCs. The initiation of oscillations required an interaction between α2M* and LRP1. By using Ca2+-free medium and inhibitors of various Ca2+ signaling pathways, we demonstrated that the oscillations required entry of extracellular Ca2+ through store-operated Ca2+ channels. Finally, we found that the specific BKCa blocker paxilline inhibited the oscillations, whereas the channel opener NS11021 increased the rate of these oscillations. These data demonstrate that α2M* and LRP1 modulate the BKCa channel in human myometrium and that BKCa and its immunomodulatory interacting partners regulate Ca2+ dynamics in hMSMCs during pregnancy. PMID:27044074

  7. Essential Role of TGF-β/Smad Pathway on Statin Dependent Vascular Smooth Muscle Cell Regulation

    PubMed Central

    Rodríguez-Vita, Juan; Sánchez-Galán, Eva; Santamaría, Beatriz; Sánchez-López, Elsa; Rodrigues-Díez, Raquel; Blanco-Colio, Luís Miguel; Egido, Jesús; Ortiz, Alberto; Ruiz-Ortega, Marta

    2008-01-01

    Background The 3-hydroxy-3-methylglutaryl CoA reductase inhibitors (also called statins) exert proven beneficial effects on cardiovascular diseases. Recent data suggest a protective role for Transforming Growth Factor-β (TGF-β) in atherosclerosis by regulating the balance between inflammation and extracellular matrix accumulation. However, there are no studies about the effect of statins on TGF-β/Smad pathway in atherosclerosis and vascular cells. Methodology In cultured vascular smooth muscle cells (VSMCs) statins enhanced Smad pathway activation caused by TGF-β. In addition, statins upregulated TGF-β receptor type II (TRII), and increased TGF-β synthesis and TGF-β/Smad-dependent actions. In this sense, statins, through Smad activation, render VSMCs more susceptible to TGF-β induced apoptosis and increased TGF-β-mediated ECM production. It is well documented that high doses of statins induce apoptosis in cultured VSMC in the presence of serum; however the precise mechanism of this effect remains to be elucidated. We have found that statins-induced apoptosis was mediated by TGF-β/Smad pathway. Finally, we have described that RhoA inhibition is a common intracellular mechanisms involved in statins effects. The in vivo relevance of these findings was assessed in an experimental model of atherosclerosis in apolipoprotein E deficient mice: Treatment with Atorvastatin increased Smad3 phosphorylation and TRII overexpression, associated to elevated ECM deposition in the VSMCs within atheroma plaques, while apoptosis was not detected. Conclusions Statins enhance TGF-β/Smad pathway, regulating ligand levels, receptor, main signaling pathway and cellular responses of VSMC, including apoptosis and ECM accumulation. Our findings show that TGF-β/Smad pathway is essential for statins-dependent actions in VSMCs. PMID:19088845

  8. Monocyte/macrophage cytokine activity regulates vascular smooth muscle cell function within a degradable polyurethane scaffold.

    PubMed

    Battiston, K G; Ouyang, B; Labow, R S; Simmons, C A; Santerre, J P

    2014-03-01

    Tissue engineering strategies rely on the ability to promote cell proliferation and migration into porous biomaterial constructs, as well as to support specific phenotypic states of the cells in vitro. The present study investigated the use of released factors from monocytes and their derived macrophages (MDM) and the mechanism by which they regulate vascular smooth muscle cell (VSMC) response in a VSMC-monocyte co-culture system within a porous degradable polyurethane (D-PHI) scaffold. VSMCs cultured in monocyte/MDM-conditioned medium (MCM), generated from the culture of monocytes/MDM on D-PHI scaffolds for up to 28 days, similarly affected VSMC contractile marker expression, growth and three-dimensional migration when compared to direct VSMC-monocyte co-culture. Monocyte chemotactic protein-1 (MCP-1) and interleukin-6 (IL-6) were identified as two cytokines present in MCM, at concentrations that have previously been shown to influence VSMC phenotype. VSMCs cultured alone on D-PHI scaffolds and exposed to MCP-1 (5 ng ml(-1)) or IL-6 (1 ng ml(-1)) for 7 days experienced a suppression in contractile marker expression (with MCP-1 or IL-6) and increased growth (with MCP-1) compared to no cytokine medium supplementation. These effects were also observed in VSMC-monocyte co-culture on D-PHI. Neutralization of IL-6, but not MCP-1, was subsequently shown to decrease VSMC growth and enhance calponin expression for VSMC-monocyte co-cultures on D-PHI scaffolds for 7 days, implying that IL-6 mediates VSMC response in monocyte-VSMC co-cultures. This study highlights the use of monocytes and their derived macrophages in conjunction with immunomodulatory biomaterials, such as D-PHI, as agents for regulating VSMC response, and demonstrates the importance of monocyte/MDM-released factors, such as IL-6 in particular, in this process.

  9. Regulation of vascular smooth muscle phenotype by cross-regulation of krüppel-like factors

    PubMed Central

    Ha, Jung Min; Yun, Sung Ji; Jin, Seo Yeon; Lee, Hye Sun; Kim, Sun Ja; Shin, Hwa Kyoung

    2017-01-01

    Regulation of vascular smooth muscle cell (VSMC) phenotype plays an essential role in many cardiovascular diseases. In the present study, we provide evidence that krüppel-like factor 8 (KLF8) is essential for tumor necrosis factor α (TNFα)-induced phenotypic conversion of VSMC obtained from thoracic aorta from 4-week-old SD rats. Stimulation of the contractile phenotype of VSMCs with TNFα significantly reduced the VSMC marker gene expression and KLF8. The gene expression of KLF8 was blocked by TNFα stimulation in an ERK-dependent manner. The promoter region of KLF8 contained putative Sp1, KLF4, and NFκB binding sites. Myocardin significantly enhanced the promoter activity of KLF4 and KLF8. The ectopic expression of KLF4 strongly enhanced the promoter activity of KLF8. Moreover, silencing of Akt1 significantly attenuated the promoter activity of KLF8; conversely, the overexpression of Akt1 significantly enhanced the promoter activity of KLF8. The promoter activity of SMA, SM22α, and KLF8 was significantly elevated in the contractile phenotype of VSMCs. The ectopic expression of KLF8 markedly enhanced the expression of SMA and SM22α concomitant with morphological changes. The overexpression of KLF8 stimulated the promoter activity of SMA. Stimulation of VSMCs with TNFα enhanced the expression of KLF5, and the promoter activity of KLF5 was markedly suppressed by KLF8 ectopic expression. Finally, the overexpression of KLF5 suppressed the promoter activity of SMA and SM22α, thereby reduced the contractility in response to the stimulation of angiotensin II. These results suggest that cross-regulation of KLF family of transcription factors plays an essential role in the VSMC phenotype. PMID:28066139

  10. CD36 Differently Regulates Macrophage Responses to Smooth and Rough Lipopolysaccharide

    PubMed Central

    Biedroń, Rafał; Peruń, Angelika; Józefowski, Szczepan

    2016-01-01

    Lipopolysaccharide (LPS) is the major pathogen-associated molecular pattern of Gram-negative bacterial infections, and includes smooth (S-LPS) and rough (R-LPS) chemotypes. Upon activation by LPS through CD14, TLR4/MD-2 heterodimers sequentially induce two waves of intracellular signaling for macrophage activation: the MyD88-dependent pathway from the plasma membrane and, following internalization, the TRIF-dependent pathway from endosomes. We sought to better define the role of scavenger receptors CD36 and CD204/SR-A as accessory LPS receptors that can contribute to pro-inflammatory and microbicidal activation of macrophages. We have found that CD36 differently regulates activation of mouse macrophages by S-LPS versus R-LPS. The ability of CD36 to substitute for CD14 in loading R-LPS, but not S-LPS onto TLR4/MD-2 allows CD14-independent macrophage responses to R-LPS. Conversely, S-LPS, but not R-LPS effectively stimulates CD14 binding to CD36, which favors S-LPS transfer from CD14 onto TLR4/MD-2 under conditions of low CD14 occupancy with S-LPS in serum-free medium. In contrast, in the presence of serum, CD36 reduces S-LPS binding to TLR4/MD-2 and the subsequent MyD88-dependent signaling, by mediating internalization of S-LPS/CD14 complexes. Additionally, CD36 positively regulates activation of TRIF-dependent signaling by both S-LPS and R-LPS, by promoting TLR4/MD-2 endocytosis. In contrast, we have found that SR-A does not function as a S-LPS receptor. Thus, by co-operating with CD14 in both R- and S-LPS loading onto TLR4/MD-2, CD36 can enhance the sensitivity of tissue-resident macrophages in detecting infections by Gram-negative bacteria. However, in later phases, following influx of serum to the infection site, the CD36-mediated negative regulation of MyD88-dependent branch of S-LPS-induced TLR4 signaling might constitute a mechanism to prevent an excessive inflammatory response, while preserving the adjuvant effect of S-LPS for adaptive immunity. PMID

  11. Regulation of smooth muscle cell scavenger receptor expression in vivo by atherogenic diets and in vitro by cytokines.

    PubMed Central

    Li, H; Freeman, M W; Libby, P

    1995-01-01

    Scavenger receptor (ScR)-mediated uptake of modified lipoproteins may contribute to the transformation of smooth muscle cells into lipid-laden foam cells during atherogenesis. This study examined the in vivo expression of ScRs in aortas, with or without balloon injury, taken from hypercholesterolemic or normocholesterolemic rabbits. Numerous intimal cells in the rabbit aortic lesions expressed ScRs as detected by immunocytochemical staining with a goat anti-rabbit ScR antibody. Single immunostaining for cell identification markers in serial sections, as well as double staining, confirmed the expression of ScRs by both intimal smooth muscle cells and macrophages. To explore potential inducers of ScR expression by smooth muscle cells in vivo, we studied the regulation of ScR expression in vitro by cytokines known to be present in atherosclerotic lesions. Tumor necrosis factor-alpha (TNF-alpha) or interferon-gamma (IFN-gamma) increased ScR mRNA levels, protein expression, and AcLDL degradative activity in cultured rabbit aortic smooth muscle cells. The induction of ScR expression in intimal smooth muscle cells in vivo could be a useful marker of smooth muscle cell activation during atherogenesis and may contribute to foam cell formation by this cell type following balloon injury and/or hypercholesterolemia. Cytokines, such as TNF-alpha or IFN-gamma, may stimulate some of the phenotypic changes that characterize the alteration in gene expression of intimal smooth muscle cells in rabbit atherosclerotic lesions. Images PMID:7814605

  12. Testosterone regulates smooth muscle contractile pathways in the rat prostate: emphasis on PDE5 signaling

    PubMed Central

    Zhang, Xinhua; Zang, Ning; Wei, Yu; Yin, Jin; Teng, Ruobing; Seftel, Allen

    2012-01-01

    Testosterone (T) plays a permissive role in the development of benign prostatic hyperplasia (BPH), and phosphodiesterase 5 inhibitors (PDE5is) have been found to be effective for BPH and lower urinary tract symptoms (LUTS) in clinical trials. This study investigated the effect of T on smooth muscle (SM) contractile and regulatory signaling pathways, including PDE5 expression and functional activity in prostate in male rats (sham-operated, surgically castrated, and castrated with T supplementation). In vitro organ bath studies, real-time RT-PCR, Western blot analysis, and immunohistochemistry were performed. Castration heavily attenuated contractility, including sensitivity to phenylephrine with SM myosin immunostaining revealing a disrupted SM cell arrangement in the stroma. PDE5 was immunolocalized exclusively in the prostate stroma, and orchiectomy signficantly reduced PDE5 immunopositivity, mRNA, and protein expression, along with nNOS and ROKβ mRNA, whereas it increased eNOS plus α1a and α1b adrenoreceptor expression in castrated animals. The PDE5i zaprinast significantly increased prostate strip relaxation to the nitric oxide donor sodium nitroprusside (SNP) in control but not castrated rats. But SNP alone was more effective on castrated rats, comparable with sham treated with SNP plus zaprinast. T supplementation prevented or restored all above changes, including SNP and zaprinast in vitro responsiveness. In conclusion, our data show that T positively regulates PDE5 expression and functional activities in prostate, and T ablation not only suppresses prostate size but also reduces prostatic SM contractility, with several potential SM contraction/relaxation pathways implicated. Zaprinast findings strongly suggest a major role for PDE5/cGMP in this signaling cascade. PDE5 inhibition may represent a novel mechanism for treatment of BPH. PMID:22028410

  13. Mechanism regulating proasthmatic effects of prolonged homologous beta2-adrenergic receptor desensitization in airway smooth muscle.

    PubMed

    Nino, Gustavo; Hu, Aihua; Grunstein, Judith S; Grunstein, Michael M

    2009-10-01

    Use of long-acting beta(2)-adrenergic receptor (beta2AR) agonists to treat asthma incurs an increased risk of asthma morbidity with impaired bronchodilation and heightened bronchoconstriction, reflecting the adverse effects of prolonged homologous beta2AR desensitization on airway smooth muscle (ASM) function. Since phosphodiesterase 4 (PDE4) regulates ASM relaxation and contractility, we examined whether the changes in ASM function induced by prolonged homologous beta2AR desensitization are attributed to altered expression and action of PDE4. Cultured human ASM cells and isolated rabbit ASM tissues exposed for 24 h to the long-acting beta2AR agonist salmeterol exhibited impaired acute beta2AR-mediated cAMP accumulation and relaxation, respectively, together with ASM constrictor hyperresponsiveness. These proasthmatic-like changes in ASM function were associated with upregulated PDE4 activity due to enhanced expression of the PDE4D5 isoform and were prevented by pretreating the ASM preparations with the PDE4 inhibitor rolipram or with inhibitors of either PKA or ERK1/2 signaling. Extended studies using gene silencing and pharmacological approaches demonstrated that: 1) the mechanism underlying upregulated PDE4D5 expression following prolonged beta2AR agonist exposure involves PKA-dependent activation of G(i) protein signaling via its betagamma-subunits, which elicits downstream activation of ERK1/2 and its induction of PDE4D5 transcription; and 2) the induction of PDE4 activity and consequent changes in ASM responsiveness are prevented by pretreating the beta2AR agonist-exposed ASM preparations with inhibitors of G(i)-betagamma signaling. Collectively, these findings identify that the proasthmatic changes in ASM function resulting from prolonged homologous beta2AR desensitization are attributed to upregulated PDE4 expression induced by G(i)-betagamma-mediated cross-talk between the PKA and ERK1/2 signaling pathways.

  14. Epigenetic regulation of COL15A1 in smooth muscle cell replicative aging and atherosclerosis

    PubMed Central

    Connelly, Jessica J.; Cherepanova, Olga A.; Doss, Jennifer F.; Karaoli, Themistoclis; Lillard, Travis S.; Markunas, Christina A.; Nelson, Sarah; Wang, Tianyuan; Ellis, Peter D.; Langford, Cordelia F.; Haynes, Carol; Seo, David M.; Goldschmidt-Clermont, Pascal J.; Shah, Svati H.; Kraus, William E.; Hauser, Elizabeth R.; Gregory, Simon G.

    2013-01-01

    Smooth muscle cell (SMC) proliferation is a hallmark of vascular injury and disease. Global hypomethylation occurs during SMC proliferation in culture and in vivo during neointimal formation. Regardless of the programmed or stochastic nature of hypomethylation, identifying these changes is important in understanding vascular disease, as maintenance of a cells' epigenetic profile is essential for maintaining cellular phenotype. Global hypomethylation of proliferating aortic SMCs and concomitant decrease of DNMT1 expression were identified in culture during passage. An epigenome screen identified regions of the genome that were hypomethylated during proliferation and a region containing Collagen, type XV, alpha 1 (COL15A1) was selected by ‘genomic convergence’ for characterization. COL15A1 transcript and protein levels increased with passage-dependent decreases in DNA methylation and the transcript was sensitive to treatment with 5-Aza-2′-deoxycytidine, suggesting DNA methylation-mediated gene expression. Phenotypically, knockdown of COL15A1 increased SMC migration and decreased proliferation and Col15a1 expression was induced in an atherosclerotic lesion and localized to the atherosclerotic cap. A sequence variant in COL15A1 that is significantly associated with atherosclerosis (rs4142986, P = 0.017, OR = 1.434) was methylated and methylation of the risk allele correlated with decreased gene expression and increased atherosclerosis in human aorta. In summary, hypomethylation of COL15A1 occurs during SMC proliferation and the consequent increased gene expression may impact SMC phenotype and atherosclerosis formation. Hypomethylated genes, such as COL15A1, provide evidence for concomitant epigenetic regulation and genetic susceptibility, and define a class of causal targets that sit at the intersection of genetic and epigenetic predisposition in the etiology of complex disease. PMID:23912340

  15. Intracellular calcium in canine cultured tracheal smooth muscle cells is regulated by M3 muscarinic receptors.

    PubMed Central

    Yang, C. M.; Yo, Y. L.; Wang, Y. Y.

    1993-01-01

    1. The regulation of cytosolic Ca2+ concentrations ([Ca2+]i) during exposure to carbachol was measured directly in canine cultured tracheal smooth muscle cells (TSMCs) loaded with fura-2. Stimulation of muscarinic cholinoceptors (muscarinic AChRs) by carbachol produced a dose-dependent rise in [Ca2+]i which was followed by a stable plateau phase. The EC50 values of carbachol for the peak and sustained plateau responses were 0.34 and 0.33 microM, respectively. 2. Atropine (10 microM) prevented all the responses to carbachol, and when added during a response to carbachol, significantly, but not completely decreased [Ca2+]i within 5 s. Therefore, the changes in [Ca2+]i by carbachol were mediated through the muscarinic AChRs. 3. AF-DX 116 (a selective M2 antagonist) and 4-diphenylacetoxy-N-methylpiperidine (4-DAMP, a selective M3 antagonist) inhibited the carbachol-stimulated increase in [Ca2+]i with pKB values of 6.4 and 9.4, respectively, corresponding to low affinity for AF-DX 119 and high affinity for 4-DAMP in antagonizing this response. 4. The plateau elevation of [Ca2+]i was dependent on the presence of external Ca2+. Removal of Ca2+ by the addition of 2 mM EGTA caused the [Ca2+]i to decline rapidly to the resting level. In the absence of external Ca2+, only an initial transient peak of [Ca2+]i was seen which then declined to the resting level; the sustained elevation of [Ca2+]i could then be evoked by the addition of Ca2+ (1.8 mM) in the continued presence of carbachol.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8298822

  16. Effects of Ginger and Its Constituents on Airway Smooth Muscle Relaxation and Calcium Regulation

    PubMed Central

    Siviski, Matthew E.; Zhang, Yi; Xu, Carrie; Hoonjan, Bhupinder; Emala, Charles W.

    2013-01-01

    The prevalence of asthma has increased in recent years, and is characterized by airway hyperresponsiveness and inflammation. Many patients report using alternative therapies to self-treat asthma symptoms as adjuncts to short-acting and long-acting β-agonists and inhaled corticosteroids (ICS). As many as 40% of patients with asthma use herbal therapies to manage asthma symptoms, often without proven efficacy or known mechanisms of action. Therefore, investigations of both the therapeutic and possible detrimental effects of isolated components of herbal treatments on the airway are important. We hypothesized that ginger and its active components induce bronchodilation by modulating intracellular calcium ([Ca2+]i) in airway smooth muscle (ASM). In isolated human ASM, ginger caused significant and rapid relaxation. Four purified constituents of ginger were subsequently tested for ASM relaxant properties in both guinea pig and human tracheas: [6]-gingerol, [8]-gingerol, and [6]-shogaol induced rapid relaxation of precontracted ASM (100–300 μM), whereas [10]-gingerol failed to induce relaxation. In human ASM cells, exposure to [6]-gingerol, [8]-gingerol, and [6]-shogaol, but not [10]-gingerol (100 μM), blunted subsequent Ca2+ responses to bradykinin (10 μM) and S-(−)-Bay K 8644 (10 μM). In A/J mice, the nebulization of [8]-gingerol (100 μM), 15 minutes before methacholine challenge, significantly attenuated airway resistance, compared with vehicle. Taken together, these novel data show that ginger and its isolated active components, [6]-gingerol, [8]-gingerol, and [6]-shogaol, relax ASM, and [8]-gingerol attenuates airway hyperresponsiveness, in part by altering [Ca2+]i regulation. These purified compounds may provide a therapeutic option alone or in combination with accepted therapeutics, including β2-agonists, in airway diseases such as asthma. PMID:23065130

  17. Sphingosine-1-Phosphate Receptor Subtypes Differentially Regulate Smooth Muscle Cell Phenotype

    PubMed Central

    Wamhoff, Brian R.; Lynch, Kevin R.; Macdonald, Timothy L.; Owens, Gary K.

    2008-01-01

    Objective The role of sphingosine-1-phosphate (S1P) receptors in acute vascular injury and smooth muscle cell (SMC) phenotypic modulation is not completely resolved. Methods and Results S1P receptor antagonists were used to test the hypothesis that specific S1P receptor subtypes differentially regulate SMC phenotypic modulation. In response to acute balloon injury of the rat carotid artery, S1P1/S1P3 receptor mRNA levels were transiently increased at 48 hours whereas S1P2 receptor expression was decreased. S1P2 expression was reinduced and increased at 7 to 10 days postinjury. Daily intraperitoneal injection of the S1P1/S1P3 antagonist VPC44116 decreased neointimal hyperplasia by ≈50%. In vitro, pharmacological inhibition of S1P1/S1P3 receptors with VPC25239 attenuated S1P-induced proliferation of rat aortic SMCs. Conversely, inhibition of S1P2 with JTE013 potentiated S1P-induced proliferation. Inhibition of S1P1/S1P3 resulted in S1P-induced activation of the SMC differentiation marker genes SMα-actin and SMMHC, whereas inhibition of S1P2 attenuated this response. S1P2-dependent activation of SMα-actin and SMMHC was shown to be mediated by L-type voltage-gated Ca2+ channels and subsequent RhoA/Rho kinase– dependent SRF enrichment of CArG box promoter regions. Conclusion Results provide evidence that S1P1/S1P3 receptors promote, whereas S1P2 receptors antagonize, SMC proliferation and phenotypic modulation in vitro in response to S1P, or in vivo after vascular injury. PMID:18535287

  18. Functional regulation of ClC-3 in the migration of vascular smooth muscle cells.

    PubMed

    Ganapathi, Sindura B; Wei, Shun-Guang; Zaremba, Angelika; Lamb, Fred S; Shears, Stephen B

    2013-01-01

    Migration of vascular smooth muscle cells (VSMCs) into neointima contributes to atherosclerosis and restenosis. This migration requires coordinated plasmalemmal fluxes of water and ions. Here, we show that aortic VSMC migration depends on the regulation of transmembrane Cl(-) flux by ClC-3, a Cl(-) channel/transporter. The contribution of ClC-3 to plasmalemmal Cl(-) current was studied in VSMCs by electrophysiological recordings. Cl(-) current was negligible in cells perfused with 0 [Ca(2+)]. Raising intracellular [Ca(2+)] to 0.5 μM activated a Cl(-) current (I(Cl.Ca)), approximately half of which was eliminated on inhibition by KN-93 of calmodulin-dependent protein kinase II. I(Cl.Ca) was also halved by inositol-3,4,5,6-tetrakisphosphate, a cellular signal with the biological function of specifically preventing calmodulin-dependent protein kinase II from activating I(Cl.Ca). Gene disruption of ClC-3 reduced I(Cl.Ca) by 50%. Moreover, I(Cl.Ca) in the ClC-3 null VSMCs was not affected by either KN-93 or inositol-3,4,5,6-tetrakisphosphate. We conclude that I(Cl.Ca) is composed of 2 components, one is ClC-3 independent whereas the other is ClC-3 dependent, activated by calmodulin-dependent protein kinase II and inhibited by inositol-3,4,5,6-tetrakisphosphate. We also assayed VSMC migration in transwell assays. Migration was halved in ClC-3 null cells versus wild-type cells. In addition, inhibition of ClC-3 by niflumic acid, KN-93, or inositol-3,4,5,6-tetrakisphosphate each reduced cell migration in wild-type cells but not in ClC-3 null cells. These cell-signaling roles of ClC-3 in VSMC migration suggest new therapeutic approaches to vascular remodeling diseases.

  19. UAP56 is a novel interacting partner of Bcr in regulating vascular smooth muscle cell DNA synthesis

    SciTech Connect

    Sahni, Abha; Wang, Nadan; Alexis, Jeffrey D.

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer UAP56 is an important regulator of DNA synthesis in vascular smooth muscle cells. Black-Right-Pointing-Pointer UAP56 binds to Bcr. Black-Right-Pointing-Pointer Interaction between Bcr and UAP56 is critical for Bcr induced DNA synthesis. -- Abstract: Bcr is a serine/threonine kinase that is a critical regulator of vascular smooth muscle cell inflammation and proliferation. We have previously demonstrated that Bcr acts in part via phosphorylation and inhibition of PPAR{gamma}. We have identified the RNA helicase UAP56 as another substrate of Bcr. In this report we demonstrate that knockdown of UAP56 blocks Bcr induced DNA synthesis in vascular smooth muscle cells (VSMC). We also found that over expression of Bcr increased the expression of cyclin E and decreased the expression of p27. Knockdown of UAP56 reversed the effect of Bcr on cyclin E and p27 expression. Furthermore, we found that Bcr binds to UAP56 and demonstrate that binding of UAP56 to Bcr is critical for Bcr induced DNA synthesis in VSMC. Our data identify UAP56 as an important binding partner of Bcr and a novel target for inhibiting vascular smooth muscle cell proliferation.

  20. Serum response factor regulates smooth muscle contractility via myotonic dystrophy protein kinases and L-type calcium channels

    PubMed Central

    Lee, Moon Young; Park, Chanjae; Ha, Se Eun; Park, Paul J.; Berent, Robyn M.; Jorgensen, Brian G.; Corrigan, Robert D.; Grainger, Nathan; Blair, Peter J.; Slivano, Orazio J.; Miano, Joseph M.; Ward, Sean M.; Smith, Terence K.; Sanders, Kenton M.

    2017-01-01

    Serum response factor (SRF) transcriptionally regulates expression of contractile genes in smooth muscle cells (SMC). Lack or decrease of SRF is directly linked to a phenotypic change of SMC, leading to hypomotility of smooth muscle in the gastrointestinal (GI) tract. However, the molecular mechanism behind SRF-induced hypomotility in GI smooth muscle is largely unknown. We describe here how SRF plays a functional role in the regulation of the SMC contractility via myotonic dystrophy protein kinase (DMPK) and L-type calcium channel CACNA1C. GI SMC expressed Dmpk and Cacna1c genes into multiple alternative transcriptional isoforms. Deficiency of SRF in SMC of Srf knockout (KO) mice led to reduction of SRF-dependent DMPK, which down-regulated the expression of CACNA1C. Reduction of CACNA1C in KO SMC not only decreased intracellular Ca2+ spikes but also disrupted their coupling between cells resulting in decreased contractility. The role of SRF in the regulation of SMC phenotype and function provides new insight into how SMC lose their contractility leading to hypomotility in pathophysiological conditions within the GI tract. PMID:28152551

  1. Substance P Regulates Environmental Tobacco Smoke-Enhanced Tracheal Smooth Muscle Responsiveness in Mice

    PubMed Central

    Xiao, Lan; Wu, Zhong-Xin

    2012-01-01

    Environmental tobacco smoke (ETS) is an environmental trigger that leads to airway inflammation and airway hyperresponsiveness (AHR) in susceptible individuals and animals, but the underlying mechanism is not fully understood. Substance P (SP) release from sensory nerve fibers has been linked to AHR. The present experiments characterize the role of SP in tracheal smooth muscle on ETS-increased airway responses. The mice were exposed to either sidestream tobacco smoke (SS), a surrogate to ETS, or filtered air (FA) for 1 day or 5 consecutive days. Contractions of tracheal smooth muscle to SP and electrical field stimulation (EFS) were not significantly altered in 1 of day SS-exposed mice. However, 5 of days SS exposure significantly increased airway smooth muscle contractions to SP and EFS. Administration of CP-99994, an antagonist of the neurokinin (NK)1 receptor, attenuates the SS exposure-enhanced tracheal smooth muscle responses to EFS. Furthermore, the immunohistochemistry showed that SP nerve fibers were increased in tracheal smooth muscle after 5 of days SS exposure. These results suggest that the increased SP production may contribute to SS-enhanced smooth muscle responsiveness in mice trachea. PMID:22927867

  2. Role of Telokin in Regulating Murine Gastric Fundus Smooth Muscle Tension.

    PubMed

    An, Changlong; Bhetwal, Bhupal P; Sanders, Kenton M; Somlyo, Avril V; Perrino, Brian A

    2015-01-01

    Telokin phosphorylation by cyclic GMP-dependent protein kinase facilitates smooth muscle relaxation. In this study we examined the relaxation of gastric fundus smooth muscles from basal tone, or pre-contracted with KCl or carbachol (CCh), and the phosphorylation of telokin S13, myosin light chain (MLC) S19, MYPT1 T853, T696, and CPI-17 T38 in response to 8-Bromo-cGMP, the NO donor sodium nitroprusside (SNP), or nitrergic neurotransmission. We compared MLC phosphorylation and the contraction and relaxation responses of gastric fundus smooth muscles from telokin-/- mice and their wild-type littermates to KCl or CCh, and 8-Bromo-cGMP, SNP, or nitrergic neurotransmission, respectively. We compared the relaxation responses and telokin phosphorylation of gastric fundus smooth muscles from wild-type mice and W/WV mice which lack ICC-IM, to 8-Bromo-cGMP, SNP, or nitrergic neurotransmission. We found that telokin S13 is basally phosphorylated and that 8-Bromo-cGMP and SNP increased basal telokin phosphorylation. In muscles pre-contracted with KCl or CCh, 8-Bromo-cGMP and SNP had no effect on CPI-17 or MYPT1 phosphorylation, but increased telokin phosphorylation and reduced MLC phosphorylation. In telokin-/- gastric fundus smooth muscles, basal tone and constitutive MLC S19 phosphorylation were increased. Pre-contracted telokin-/- gastric fundus smooth muscles have increased contractile responses to KCl, CCh, or cholinergic neurotransmission and reduced relaxation to 8-Bromo-cGMP, SNP, and nitrergic neurotransmission. However, basal telokin phosphorylation was not increased when muscles were stimulated with lower concentrations of SNP or when the muscles were stimulated by nitrergic neurotransmission. SNP, but not nitrergic neurotransmission, increased telokin Ser13 phosphorylation in both wild-type and W/WV gastric fundus smooth muscles. Our findings indicate that telokin may play a role in attenuating constitutive MLC phosphorylation and provide an additional mechanism to

  3. E3 ubiquitin ligase isolated by differential display regulates cervical cancer growth in vitro and in vivo via microRNA-143.

    PubMed

    Li, Jibin; Wang, Xinling; Zhang, Yanshang; Zhang, Yan

    2016-08-01

    Cervical cancer is one of the most common gynecological cancers worldwide. Aberrant expression of E3 ubiquitin ligase isolated by differential display (EDD) has been detected in various types of tumor and has been demonstrated to have an important role in carcinogenesis, tumor growth and drug resistance. However, the role of EDD in cervical cancer and its underlying molecular mechanisms remains unknown. The present study aimed to investigate the role of EDD in the tumorigenicity of cervical cancer. EDD expression levels were measured using reverse transcription-quantitative polymerase chain reaction and western blotting in SiHa, HeLa, CaSki, c-41 and c-33A cervical cancer cell lines and cervical cancer tissue specimens. A functional study was performed using cell proliferation, colony formation, cell apoptosis assays in vitro and tumor growth assays in vivo with EDD either overexpressed or silenced. In the present study, EDD expression levels were significantly upregulated in cervical cancer cell lines and tissue samples. EDD knockdown significantly inhibited colony formation, cell proliferation and tumor growth and accelerated cell apoptosis in the cervical cancer cell lines and tissue samples. Furthermore, microRNA (miR)-143 expression levels were low in cervical cancer tissue samples and were negatively correlated with EDD expression. miR-143 silencing eliminated the effect of EDD on cell proliferation, colony formation and cell apoptosis in the cervical cancer cells, which suggested that miR-143 is critical for EDD-mediated regulation of cervical cancer cell growth. The results of the present study indicated that EDD may promote cervical cancer growth in vivo and in vitro by targeting miR-143. In conclusion, EDD may have an oncogenic role in cervical cancer and may serve as a potential therapeutic target for the treatment of patients with cervical cancer.

  4. Atherosclerosis-prone hemodynamics differentially regulates endothelial and smooth muscle cell phenotypes and promotes pro-inflammatory priming.

    PubMed

    Hastings, Nicole E; Simmers, Michael B; McDonald, Oliver G; Wamhoff, Brian R; Blackman, Brett R

    2007-12-01

    Atherosclerosis is an inflammatory disease that preferentially forms at hemodynamically compromised regions of altered shear stress patterns. Endothelial cells (EC) and smooth muscle cells (SMC) undergo phenotypic modulation during atherosclerosis. An in vitro coculture model was developed to determine the role of hemodynamic regulation of EC and SMC phenotypes in coculture. Human ECs and SMCs were plated on a synthetic elastic lamina and human-derived atheroprone, and atheroprotective shear stresses were imposed on ECs. Atheroprone flow decreased genes associated with differentiated ECs (endothelial nitric oxide synthase, Tie2, and Kruppel-like factor 2) and SMCs (smooth muscle alpha-actin and myocardin) and induced a proinflammatory phenotype in ECs and SMCs (VCAM-1, IL-8, and monocyte chemoattractant protein-1). Atheroprone flow-induced changes in SMC differentiation markers were regulated at the chromatin level, as indicated by decreased serum response factor (SRF) binding to the smooth muscle alpha-actin-CC(a/T)(6)GG (CArG) promoter region and decreased histone H(4) acetylation. Conversely, SRF and histone H(4) acetylation were enriched at the c-fos promoter in SMCs. In the presence of atheroprotective shear stresses, ECs aligned with the direction of flow and SMCs aligned more perpendicular to flow, similar to in vivo vessel organization. These results provide a novel mechanism whereby modulation of the EC phenotype by hemodynamic shear stresses, atheroprone or atheroprotective, play a critical role in mechanical-transcriptional coupling and regulation of the SMC phenotype.

  5. Signal-transduction pathways that regulate visceral smooth muscle function. III. Coupling of muscarinic receptors to signaling kinases and effector proteins in gastrointestinal smooth muscles.

    PubMed

    Gerthoffer, William T

    2005-05-01

    Stimulation of muscarinic M3 and M2 receptors on gastrointestinal smooth muscle elicits contraction via activation of G proteins that are coupled to a diverse set of downstream signaling pathways and effector proteins. Many studies suggest a canonical excitation-contraction coupling pathway that includes activation of phospholipases, production of inositol 1,4,5-trisphosphate and diacylglycerol, release of calcium from the sarcoplasmic reticulum, activation of L-type calcium channels, and activation of nonselective cation channels. These events lead to elevated intracellular calcium concentration, which activates myosin light chain kinase to phosphorylate and activate myosin II thus causing contraction. In addition, muscarinic receptors are coupled to signaling pathways that modulate the effect of activator calcium. The Rho/Rho kinase pathway inhibits myosin light chain phosphatase, one of the key steps in sensitization of the contractile proteins to calcium. Phosphatidylinositol 3-kinases and Src family tyrosine kinases are also activated by muscarinic agonists. Src family tyrosine kinases regulate L-type calcium and nonselective cation channels. Src activation also leads to activation of ERK and p38 MAPKs. ERK MAPKs phosphorylate caldesmon, an actin filament binding protein. P38 MAPKs activate phospholipases and MAPKAP kinase 2/3, which phosphorylate HSP27. HSP27 may regulate cross-bridge function, actin filament formation, and actin filament attachment to the cell membrane. In addition to the well-known role of M3 muscarinic receptors to regulate myoplasmic calcium levels, the integrated effect of muscarinic activation probably also includes signaling pathways that modulate phospholipases, cyclic nucleotides, contractile protein function, and cytoskeletal protein function.

  6. The role of K⁺ conductances in regulating membrane excitability in human gastric corpus smooth muscle.

    PubMed

    Lee, Ji Yeon; Ko, Eun-Ju; Ahn, Ki Duck; Kim, Sung; Rhee, Poong-Lyul

    2015-04-01

    Changes in resting membrane potential (RMP) regulate membrane excitability. K(+) conductance(s) are one of the main factors in regulating RMP. The functional role of K(+) conductances has not been studied the in human gastric corpus smooth muscles (HGCS). To examine the role of K(+) channels in regulation of RMP in HGCS we employed microelectrode recordings, patch-clamp, and molecular approaches. Tetraethylammonium and charybdotoxin did not affect the RMP, suggesting that BK channels are not involved in regulating RMP. Apamin, a selective small conductance Ca(2+)-activated K(+) channel (SK) blocker, did not show a significant effect on the membrane excitability. 4-Aminopyridine, a Kv channel blocker, caused depolarization and increased the duration of slow wave potentials. 4-Aminopyridine also inhibited a delayed rectifying K(+) current in isolated smooth muscle cells. End-product RT-PCR gel detected Kv1.2 and Kv1.5 in human gastric corpus muscles. Glibenclamide, an ATP-sensitive K(+) channel (KATP) blocker, did not induce depolarization, but nicorandil, a KATP opener, hyperpolarized HGCS, suggesting that KATP are expressed but not basally activated. Kir6.2 transcript, a pore-forming subunit of KATP was expressed in HGCS. A low concentration of Ba(2+), a Kir blocker, induced strong depolarization. Interestingly, Ba(2+)-sensitive currents were minimally expressed in isolated smooth muscle cells under whole-cell patch configuration. KCNJ2 (Kir2.1) transcript was expressed in HGCS. Unique K(+) conductances regulate the RMP in HGCS. Delayed and inwardly rectifying K(+) channels are the main candidates in regulating membrane excitability in HGCS. With the development of cell dispersion techniques of interstitial cells, the cell-specific functional significance will require further analysis.

  7. Smooth muscle myosin regulation by serum and cell density in cultured rat lung connective tissue cells.

    PubMed

    Babij, P; Zhao, J; White, S; Woodcock-Mitchell, J; Mitchell, J; Absher, M; Baldor, L; Periasamy, M; Low, R B

    1993-08-01

    RNA and protein analyses were used to detect expression of SM1 and SM2 smooth muscle myosin heavy chain (MHC) in cultured adult rat lung connective tissue cells (RL-90). Smooth muscle MHC mRNA expression in confluent cells grown in 10% serum was approximately 50% of the level in adult stomach. Similar results were obtained in cells cultured at low density (25% confluency) in 1% serum. However, in low-density cultures transferred to 10% serum for 24 h, the level of MHC mRNA decreased to approximately 20% of that in adult stomach. Smooth muscle alpha-actin showed a pattern of expression similar to that for smooth muscle MHC. Expression of nonmuscle MHC-A mRNA was higher in all culture conditions compared to stomach. MHC-A mRNA expression was less in low-density cultures in low serum and increased when low-density cultures were transferred to 10% serum for 24 h. MHC-B mRNA expression was less in low- vs. high-density cultures. In contrast to MHC-A, however, MHC-B mRNA expression in low-density cultures was higher in low serum. Immunofluorescence and immunoblotting with SM1-specific antibody demonstrated the presence of the SM1 protein isoform as well as reactivity to a protein band migrating slightly faster than SM2. These results demonstrate that cultured rat lung connective tissue cells express smooth muscle MHC and that expression is modulated by culture conditions.

  8. Benidipine, a calcium channel blocker, regulates proliferation and phenotype of vascular smooth muscle cells.

    PubMed

    Arakawa, Emi; Hasegawa, Kazuhide

    2006-02-01

    Hyperproliferation of phenotypically modified vascular smooth muscle cells (VSMCs) is one of the major factors in the development of atherosclerosis and restenosis. Previously it was demonstrated that benidipine, a dihydropyridine-calcium channel antagonist, reduced neointimal formation in a rat balloon-injury model. In the present study, we examined the effect of benidipine on the phenotypic modulation and proliferation of VSMCs, using primary cultures of rat VSMCs. In the absence of drug treatment, protein levels of the smooth muscle specific markers, such as smooth muscle myosin heavy chain-1 (SM1), calponin 1, and alpha-actin, decreased during culture. However, treatment of VSMCs with benidipine (3 - 10 micromol/L) for 1 week reversed the effect in a concentration-related manner so that high levels of marker proteins were maintained. The expression of calponin mRNAs was reduced markedly during 1-week culture, and treatment with benidipine (3 micromol/L) significantly inhibited the reduction. Treatment with benidipine for 2 days increased the level of p21 protein and partially reduced p70 S6 kinase 1 (p70S6K1) activity. These data suggest that benidipine may arrest the growth of VSMCs, thereby preventing cell dedifferentiation. These additional properties of benidipine suggest that the drug should provide useful therapy for atherosclerosis and restenosis.

  9. YAP is up-regulated in the bronchial airway smooth muscle of the chronic asthma mouse model

    PubMed Central

    Zhou, Jing; Xu, Fei; Yu, Jing Jing; Zhang, Wei

    2015-01-01

    Asthma is characterized by leukocytic infiltration and tissue remodeling with structural changes including subepithelial fibrosis and ASM cells proliferation. The Hippo pathway is a key regulatory point involved in cell proliferation, fibroblasts, and smooth muscle cell differentiation. In order to disclose the relation between asthma and the Hippo pathway, expression of the Yes-associated protein (YAP), a key gene in the Hippo pathway, in the bronchial smooth muscle of chronic asthma model (CAM) was studied. 40 mice were randomly divided into control (wide type) and experimental group to construct CAM using chicken ovalbumin (OVA). Pathological changes of the lung tissues were observed in the CAM mice compared with the control using HE staining method. Immunohistochemistry (IHC) was used to detect if YAP protein is expressed in the lung tissues. The pathological changes of the CAM group showed that a large number of inflammatory cells infiltration including mainly lymphocytes and a small amount of eosinophilic, with the presence of certain airway smooth muscle hyperplasia, was observed in comparison with the control. IHC results showed that the YAP protein was significantly increased compared with the control groups (P < 0.01). This result was further confirmed by quantitative real-time PCR (qPCR) assay which detected the up-regulation of the YAP gene (P < 0.01) and Western blot. In conclusion, the YAP protein was significantly expressed in the bronchial airway tissues of the CAM mice, and could be used as an indicator for asthma. PMID:26617833

  10. Coronary artery disease associated transcription factor TCF21 regulates smooth muscle precursor cells that contribute to the fibrous cap

    PubMed Central

    Nurnberg, S.T.; Cheng, K.; Raiesdana, A.; Kundu, R.; Miller, C.L.; Kim, J.B.; Arora, K.; Carcamo-Oribe, I.; Xiong, Y.; Tellakula, N.; Nanda, V.; Murthy, N.; Boisvert, W.A.; Hedin, U.; Perisic, L.; Aldi, S.; Maegdefessel, L.; Pjanic, M.; Owens, G.K.; Tallquist, M.D.; Quertermous, T.

    2015-01-01

    TCF21 is a basic helix–loop–helix transcription factor that has recently been implicated as contributing to susceptibility to coronary heart disease based on genome wide association studies. In order to identify transcriptionally regulated target genes in a major disease relevant cell type, we performed siRNA knockdown of TCF21 in in vitro cultured human coronary artery smooth muscle cells and compared the transcriptome of siTCF21 versus siCONTROL treated cells. The raw (FASTQ) as well as processed (BED) data from 3 technical replicates per treatment has been deposited with Gene Expression Omnibus (GSE44461). PMID:26090325

  11. Differential regulation of protease activated receptor-1 and tissue plasminogen activator expression by shear stress in vascular smooth muscle cells

    NASA Technical Reports Server (NTRS)

    Papadaki, M.; Ruef, J.; Nguyen, K. T.; Li, F.; Patterson, C.; Eskin, S. G.; McIntire, L. V.; Runge, M. S.

    1998-01-01

    Recent studies have demonstrated that vascular smooth muscle cells are responsive to changes in their local hemodynamic environment. The effects of shear stress on the expression of human protease activated receptor-1 (PAR-1) and tissue plasminogen activator (tPA) mRNA and protein were investigated in human aortic smooth muscle cells (HASMCs). Under conditions of low shear stress (5 dyn/cm2), PAR-1 mRNA expression was increased transiently at 2 hours compared with stationary control values, whereas at high shear stress (25 dyn/cm2), mRNA expression was decreased (to 29% of stationary control; P<0.05) at all examined time points (2 to 24 hours). mRNA half-life studies showed that this response was not due to increased mRNA instability. tPA mRNA expression was decreased (to 10% of stationary control; P<0.05) by low shear stress after 12 hours of exposure and was increased (to 250% of stationary control; P<0.05) after 24 hours at high shear stress. The same trends in PAR-1 mRNA levels were observed in rat smooth muscle cells, indicating that the effects of shear stress on human PAR-1 were not species-specific. Flow cytometry and ELISA techniques using rat smooth muscle cells and HASMCs, respectively, provided evidence that shear stress exerted similar effects on cell surface-associated PAR-1 and tPA protein released into the conditioned media. The decrease in PAR-1 mRNA and protein had functional consequences for HASMCs, such as inhibition of [Ca2+] mobilization in response to thrombin stimulation. These data indicate that human PAR-1 and tPA gene expression are regulated differentially by shear stress, in a pattern consistent with their putative roles in several arterial vascular pathologies.

  12. Differential regulation of muscarinic M2 and M3 receptor signaling in gastrointestinal smooth muscle by caveolin-1.

    PubMed

    Bhattacharya, Sayak; Mahavadi, Sunila; Al-Shboul, Othman; Rajagopal, Senthilkumar; Grider, John R; Murthy, Karnam S

    2013-08-01

    Caveolae act as scaffolding proteins for several G protein-coupled receptor signaling molecules to regulate their activity. Caveolin-1, the predominant isoform in smooth muscle, drives the formation of caveolae. The precise role of caveolin-1 and caveolae as scaffolds for G protein-coupled receptor signaling and contraction in gastrointestinal muscle is unclear. Thus the aim of this study was to examine the role of caveolin-1 in the regulation of Gq- and Gi-coupled receptor signaling. RT-PCR, Western blot, and radioligand-binding studies demonstrated the selective expression of M2 and M3 receptors in gastric smooth muscle cells. Carbachol (CCh) stimulated phosphatidylinositol (PI) hydrolysis, Rho kinase and zipper-interacting protein (ZIP) kinase activity, induced myosin phosphatase 1 (MYPT1) phosphorylation (at Thr(696)) and 20-kDa myosin light chain (MLC20) phosphorylation (at Ser(19)) and muscle contraction, and inhibited cAMP formation. Stimulation of PI hydrolysis, Rho kinase, and ZIP kinase activity, phosphorylation of MYPT1 and MLC20, and muscle contraction in response to CCh were attenuated by methyl β-cyclodextrin (MβCD) or caveolin-1 small interfering RNA (siRNA). Similar inhibition of PI hydrolysis, Rho kinase, and ZIP kinase activity and muscle contraction in response to CCh and gastric emptying in vivo was obtained in caveolin-1-knockout mice compared with wild-type mice. Agonist-induced internalization of M2, but not M3, receptors was blocked by MβCD or caveolin-1 siRNA. Stimulation of PI hydrolysis, Rho kinase, and ZIP kinase activities in response to other Gq-coupled receptor agonists such as histamine and substance P was also attenuated by MβCD or caveolin-1 siRNA. Taken together, these results suggest that caveolin-1 facilitates signaling by Gq-coupled receptors and contributes to enhanced smooth muscle function.

  13. miR-128 regulates differentiation of hair follicle mesenchymal stem cells into smooth muscle cells by targeting SMAD2.

    PubMed

    Wang, Zhihao; Pang, Li; Zhao, Huiying; Song, Lei; Wang, Yuehui; Sun, Qi; Guo, Chunjie; Wang, Bin; Qin, Xiujiao; Pan, Aiqun

    2016-05-01

    Human hair follicle mesenchymal stem cells (hHFMSCs) are an important source of cardiovascular tissue engineering for their differentiation potential into smooth muscle cells (SMCs), yet the molecular pathways underlying such fate determination is unclear. MicroRNAs (miRNAs) are non-coding RNAs that play critical roles in cell differentiation. In present study, we found that miR-128 was remarkably decreased during the differentiation of hHFMSCs into SMCs induced by transforming growth factor-β1 (TGF-β1). Moreover, overexpression of miR-128 led to decreased expression of SMC cellular marker proteins, such as smooth muscle actin (SMA) and calponin, in TGF-β1-induced SMC differentiation. Further, we identified that miR-128 targeted the 3'-UTR of SMAD2 transcript for translational inhibition of SMAD2 protein, and knockdown of SMAD2 abrogated the promotional effect of antagomir-128 (miR-128 neutralizer) on SMC differentiation. These results suggest that miR-128 regulates the differentiation of hHFMSCs into SMCs via targeting SMAD2, a main transcription regulator in TGF-β signaling pathway involving SMC differentiation. The miR-128/SMAD2 axis could therefore be considered as a candidate target in tissue engineering and regenerative medicine for SMCs.

  14. Calcium regulation of vascular smooth muscle cell-derived matrix vesicles.

    PubMed

    Kapustin, Alexander N; Shanahan, Catherine M

    2012-07-01

    Vascular calcification is a pathological process common in patients with disorders of mineral metabolism and mediated by vascular smooth muscle cells (VSMCs). A key event in the initiation of VSMC calcification is the release of mineralization-competent matrix vesicles (MVs), small membrane-bound bodies with structural features enabling them to efficiently nucleate hydroxyapatite. These bodies are similar to MVs secreted by chondrocytes during bone development and their properties include the absence of calcification inhibitors, formation of nucleation sites, and accumulation of matrix metalloproteinases such as MMP-2. The mechanisms of MV biogenesis and loading remain poorly understood; however, emerging data have demonstrated that alterations in cytosolic calcium homeostasis can trigger multiple changes in MV composition that promote their mineralization.

  15. Force maintenance and myosin filament assembly regulated by Rho-kinase in airway smooth muscle.

    PubMed

    Lan, Bo; Deng, Linhong; Donovan, Graham M; Chin, Leslie Y M; Syyong, Harley T; Wang, Lu; Zhang, Jenny; Pascoe, Christopher D; Norris, Brandon A; Liu, Jeffrey C-Y; Swyngedouw, Nicholas E; Banaem, Saleha M; Paré, Peter D; Seow, Chun Y

    2015-01-01

    Smooth muscle contraction can be divided into two phases: the initial contraction determines the amount of developed force and the second phase determines how well the force is maintained. The initial phase is primarily due to activation of actomyosin interaction and is relatively well understood, whereas the second phase remains poorly understood. Force maintenance in the sustained phase can be disrupted by strains applied to the muscle; the strain causes actomyosin cross-bridges to detach and also the cytoskeletal structure to disassemble in a process known as fluidization, for which the underlying mechanism is largely unknown. In the present study we investigated the ability of airway smooth muscle to maintain force after the initial phase of contraction. Specifically, we examined the roles of Rho-kinase and protein kinase C (PKC) in force maintenance. We found that for the same degree of initial force inhibition, Rho-kinase substantially reduced the muscle's ability to sustain force under static conditions, whereas inhibition of PKC had a minimal effect on sustaining force. Under oscillatory strain, Rho-kinase inhibition caused further decline in force, but again, PKC inhibition had a minimal effect. We also found that Rho-kinase inhibition led to a decrease in the myosin filament mass in the muscle cells, suggesting that one of the functions of Rho-kinase is to stabilize myosin filaments. The results also suggest that dissolution of myosin filaments may be one of the mechanisms underlying the phenomenon of fluidization. These findings can shed light on the mechanism underlying deep inspiration induced bronchodilation.

  16. Differential Regulation of NOTCH2 and NOTCH3 Contribute to Their Unique Functions in Vascular Smooth Muscle Cells*

    PubMed Central

    Baeten, Jeremy T.; Lilly, Brenda

    2015-01-01

    Notch signaling is a key regulator of vascular smooth muscle cell (VSMC) phenotypes, including differentiation, proliferation, and cell survival. However, the exact contribution of the individual Notch receptors has not been thoroughly delineated. In this study, we identify unique roles for NOTCH2 and NOTCH3 in regulating proliferation and cell survival in cultured VSMCs. Our results indicate that NOTCH2 inhibits PDGF-B-dependent proliferation and its expression is decreased by PDGF-B. In contrast, NOTCH3 promotes proliferation and receptor expression is increased by PDGF-B. Additionally, data show that NOTCH3, but not NOTCH2 protects VSMCs from apoptosis and apoptosis mediators degrade NOTCH3 protein. We identified three pro-survival genes specifically regulated by NOTCH3 in cultured VSMCs and in mouse aortas. This regulation is mediated through MAP kinase signaling, which we demonstrate can be activated by NOTCH3, but not NOTCH2. Overall, this study highlights discrete roles for NOTCH2 and NOTCH3 in VSMCs and connects these roles to specific upstream regulators that control their expression. PMID:25957400

  17. DHEA attenuates PDGF-induced phenotypic proliferation of vascular smooth muscle A7r5 cells through redox regulation

    SciTech Connect

    Urata, Yoshishige; Goto, Shinji; Kawakatsu, Miho; Yodoi, Junji; Eto, Masato; Akishita, Masahiro; Kondo, Takahito

    2010-05-28

    It is known that dehydroepiandrosterone (DHEA) inhibits a phenotypic switch in vascular smooth muscle cells (VSMC) induced by platelet-derived growth factor (PDGF)-BB. However, the mechanism behind the effect of DHEA on VSMC is not clear. Previously we reported that low molecular weight-protein tyrosine phosphatase (LMW-PTP) dephosphorylates PDGF receptor (PDGFR)-{beta} via a redox-dependent mechanism involving glutathione (GSH)/glutaredoxin (GRX)1. Here we demonstrate that the redox regulation of PDGFR-{beta} is involved in the effect of DHEA on VSMC. DHEA suppressed the PDGF-BB-dependent phosphorylation of PDGFR-{beta}. As expected, DHEA increased the levels of GSH and GRX1, and the GSH/GRX1 system maintained the redox state of LMW-PTP. Down-regulation of the expression of LMW-PTP using siRNA restored the suppression of PDGFR-{beta}-phosphorylation by DHEA. A promoter analysis of GRX1 and {gamma}-glutamylcysteine synthetase ({gamma}-GCS), a rate-limiting enzyme of GSH synthesis, showed that DHEA up-regulated the transcriptional activity at the peroxisome proliferator-activated receptor (PPAR) response element, suggesting PPAR{alpha} plays a role in the induction of GRX1 and {gamma}-GCS expression by DHEA. In conclusion, the redox regulation of PDGFR-{beta} is involved in the suppressive effect of DHEA on VSMC proliferation through the up-regulation of GSH/GRX system.

  18. Estrogen-Induced Maldevelopment of the Penis Involves Down-Regulation of Myosin Heavy Chain 11 (MYH11) Expression, a Biomarker for Smooth Muscle Cell Differentiation1

    PubMed Central

    Okumu, L.A.; Bruinton, Sequoia; Braden, Tim D.; Simon, Liz; Goyal, Hari O.

    2012-01-01

    ABSTRACT Cavernous smooth muscle cells are essential components in penile erection. In this study, we investigated effects of estrogen exposure on biomarkers for smooth muscle cell differentiation in the penis. Neonatal rats received diethylstilbestrol (DES), with or without the estrogen receptor (ESR) antagonist ICI 182,780 (ICI) or the androgen receptor (AR) agonist dihydrotestosterone (DHT), from Postnatal Days 1 to 6. Tissues were collected at 7, 10, or 21 days of age. The smooth muscle cell biomarker MYH11 was studied in depth because microarray data showed it was significantly down-regulated, along with other biomarkers, in DES treatment. Quantitative real time-PCR and Western blot analyses showed 50%–80% reduction (P ≤ 0.05) in Myh11 expression in DES-treated rats compared to that in controls; and ICI and DHT coadministration mitigated the decrease. Temporally, from 7 to 21 days of age, Myh11 expression was onefold increased (P ≥ 0.05) in DES-treated rats versus threefold increased (P ≤ 0.001) in controls, implying the long-lasting inhibitory effect of DES on smooth muscle cell differentiation. Immunohistochemical localization of smooth muscle alpha actin, another biomarker for smooth muscle cell differentiation, showed fewer cavernous smooth muscle cells in DES-treated animals than in controls. Additionally, DES treatment significantly up-regulated Esr1 mRNA expression and suppressed the neonatal testosterone surge by 90%, which was mitigated by ICI coadministration but not by DHT coadministration. Collectively, results provided evidence that DES treatment in neonatal rats inhibited cavernous smooth muscle cell differentiation, as shown by down-regulation of MYH11 expression at the mRNA and protein levels and by reduced immunohistochemical staining of smooth muscle alpha actin. Both the ESR and the AR pathways probably mediate this effect. PMID:22976277

  19. Uni-axial stretching regulates intracellular localization of Hic-5 expressed in smooth-muscle cells in vivo.

    PubMed

    Kim-Kaneyama, Joo-ri; Suzuki, Wataru; Ichikawa, Kiyoko; Ohki, Takahiro; Kohno, Yoko; Sata, Masataka; Nose, Kiyoshi; Shibanuma, Motoko

    2005-03-01

    Hic-5 is a focal adhesion protein belonging to the paxillin LIM family that shuttles in and out of the nucleus. In the present study, we examined the expression of Hic-5 among mouse tissues by immunohistochemistry and found its expression only in smooth-muscle cells in several tissues. This result is consistent with a previous report on adult human tissues and contradicts the relatively ubiquitous expression of paxillin, the protein most homologous to Hic-5. One factor characterizing smooth-muscle cells in vivo is a continuous exposure to mechanical stretching in the organs. To study the involvement of Hic-5 in cellular responses to mechanical stress, we exposed mouse embryo fibroblasts to a uni-axial cyclic stretching and found that Hic-5 was relocalized from focal adhesions to stress fibers through its C-terminal LIM domains during the stress. In sharp contrast to this, paxillin did not change its focal-adhesion-based localization. Of the factors tested, which included interacting partners of Hic-5, only CRP2 (an only-LIM protein expressed in vascular smooth-muscle cells) and GIT1 were, like Hic-5, localized to stress fibers during the cyclic stretching. Interestingly, Hic-5 showed a suppressive effect on the contractile capability of cells embedded in three-dimensional collagen gels, and the effect was further augmented when CRP2 co-localized with Hic-5 to fiber structures of those cells. These results suggested that Hic-5 was a mediator of tensional force, translocating directly from focal adhesions to actin stress fibers upon mechanical stress and regulating the contractile capability of cells in the stress fibers.

  20. Glucagon-like peptide-1 inhibits vascular smooth muscle cell dedifferentiation through mitochondrial dynamics regulation.

    PubMed

    Torres, Gloria; Morales, Pablo E; García-Miguel, Marina; Norambuena-Soto, Ignacio; Cartes-Saavedra, Benjamín; Vidal-Peña, Gonzalo; Moncada-Ruff, David; Sanhueza-Olivares, Fernanda; San Martín, Alejandra; Chiong, Mario

    2016-03-15

    Glucagon-like peptide-1 (GLP-1) is a neuroendocrine hormone produced by gastrointestinal tract in response to food ingestion. GLP-1 plays a very important role in the glucose homeostasis by stimulating glucose-dependent insulin secretion, inhibiting glucagon secretion, inhibiting gastric emptying, reducing appetite and food intake. Because of these actions, the GLP-1 peptide-mimetic exenatide is one of the most promising new medicines for the treatment of type 2 diabetes. In vivo treatments with GLP-1 or exenatide prevent neo-intima layer formation in response to endothelial damage and atherosclerotic lesion formation in aortic tissue. Whether GLP-1 modulates vascular smooth muscle cell (VSMC) migration and proliferation by controlling mitochondrial dynamics is unknown. In this report, we showed that GLP-1 increased mitochondrial fusion and activity in a PKA-dependent manner in the VSMC cell line A7r5. GLP-1 induced a Ser-637 phosphorylation in the mitochondrial fission protein Drp1, and decreased Drp1 mitochondrial localization. GLP-1 inhibited PDGF-BB-induced VSMC migration and proliferation, actions inhibited by overexpressing wild type Drp1 and mimicked by the Drp1 inhibitor Mdivi-1 and by overexpressing dominant negative Drp1. These results show that GLP-1 stimulates mitochondrial fusion, increases mitochondrial activity and decreases PDGF-BB-induced VSMC dedifferentiation by a PKA/Drp1 signaling pathway. Our data suggest that GLP-1 inhibits vascular remodeling through a mitochondrial dynamics-dependent mechanism.

  1. The actin regulator zyxin reinforces airway smooth muscle and accumulates in airways of fatal asthmatics

    PubMed Central

    Blankman, Elizabeth; Jensen, Christopher C.; Krishnan, Ramaswamy; James, Alan L.; Elliot, John G.; Green, Francis H.; Liu, Jeffrey C.; Seow, Chun Y.; Park, Jin-Ah; Beckerle, Mary C.; Paré, Peter D.; Fredberg, Jeffrey J.; Smith, Mark A.

    2017-01-01

    Bronchospasm induced in non-asthmatic human subjects can be easily reversed by a deep inspiration (DI) whereas bronchospasm that occurs spontaneously in asthmatic subjects cannot. This physiological effect of a DI has been attributed to the manner in which a DI causes airway smooth muscle (ASM) cells to stretch, but underlying molecular mechanisms–and their failure in asthma–remain obscure. Using cells and tissues from wild type and zyxin-/- mice we report responses to a transient stretch of physiologic magnitude and duration. At the level of the cytoskeleton, zyxin facilitated repair at sites of stress fiber fragmentation. At the level of the isolated ASM cell, zyxin facilitated recovery of contractile force. Finally, at the level of the small airway embedded with a precision cut lung slice, zyxin slowed airway dilation. Thus, at each level zyxin stabilized ASM structure and contractile properties at current muscle length. Furthermore, when we examined tissue samples from humans who died as the result of an asthma attack, we found increased accumulation of zyxin compared with non-asthmatics and asthmatics who died of other causes. Together, these data suggest a biophysical role for zyxin in fatal asthma. PMID:28278518

  2. Autocrine secretion of osteopontin by vascular smooth muscle cells regulates their adhesion to collagen gels.

    PubMed Central

    Weintraub, A. S.; Giachelli, C. M.; Krauss, R. S.; Almeida, M.; Taubman, M. B.

    1996-01-01

    Osteopontin (OPN) is a secreted protein postulated to facilitate vascular smooth muscle cell (VSMC) adhesion and migration. Rat aortic VSMC lines were isolated after infection with recombinant retroviruses harboring OPN sense and antisense constructs. All lines grew normally in monolayer culture. On three-dimensional collagen gels, normal VSMCs and lines containing sense constructs (n=15) or empty vector (n=10) attached to gel and invaded the matrix. Four of five antisense clones did not adhere or invade. Antisense clones had lower OPN levels after stimulation with angiotensin II than sense clones or clones containing the empty vector (antisense, 257+/-102 ng/ml; sense, 473+/-104; vector, 434+/-66). Non-adhering antisense clones had lower mean OPN levels after angiotensin II stimulation (161+/-47 ng/ml) than sense or antisense lines with normal adhesion (486+/-63 ng/ml). The ability to adhere correlated with OPN levels >250 ng/ml. Adhesion and invasion were fully restored with addition of 100 to 200 ng/ml of exogenous OPN and were inhibited in normal VSMCs by incubation with 1 microgram/ml anti-OPN antibody. The autocrine secretion of OPN appears to play an important role in VSMC adhesion, spreading, and invasion. Images Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 PMID:8686750

  3. The actin regulator zyxin reinforces airway smooth muscle and accumulates in airways of fatal asthmatics.

    PubMed

    Rosner, Sonia R; Pascoe, Christopher D; Blankman, Elizabeth; Jensen, Christopher C; Krishnan, Ramaswamy; James, Alan L; Elliot, John G; Green, Francis H; Liu, Jeffrey C; Seow, Chun Y; Park, Jin-Ah; Beckerle, Mary C; Paré, Peter D; Fredberg, Jeffrey J; Smith, Mark A

    2017-01-01

    Bronchospasm induced in non-asthmatic human subjects can be easily reversed by a deep inspiration (DI) whereas bronchospasm that occurs spontaneously in asthmatic subjects cannot. This physiological effect of a DI has been attributed to the manner in which a DI causes airway smooth muscle (ASM) cells to stretch, but underlying molecular mechanisms-and their failure in asthma-remain obscure. Using cells and tissues from wild type and zyxin-/- mice we report responses to a transient stretch of physiologic magnitude and duration. At the level of the cytoskeleton, zyxin facilitated repair at sites of stress fiber fragmentation. At the level of the isolated ASM cell, zyxin facilitated recovery of contractile force. Finally, at the level of the small airway embedded with a precision cut lung slice, zyxin slowed airway dilation. Thus, at each level zyxin stabilized ASM structure and contractile properties at current muscle length. Furthermore, when we examined tissue samples from humans who died as the result of an asthma attack, we found increased accumulation of zyxin compared with non-asthmatics and asthmatics who died of other causes. Together, these data suggest a biophysical role for zyxin in fatal asthma.

  4. Apolipoprotein serum amyloid A down-regulates smooth-muscle cell lipid biosynthesis.

    PubMed Central

    Schreiber, B M; Veverbrants, M; Fine, R E; Blusztajn, J K; Salmona, M; Patel, A; Sipe, J D

    1999-01-01

    The addition of acute-phase apolipoprotein serum amyloid A (SAA) to cultured aortic smooth-muscle cells caused a decrease in the incorporation of [(14)C]acetate into lipids. Optimal inhibition of lipid biosynthesis was achieved with 2 microM SAA, and the effect was maintained for up to 1 week when SAA was included in the culture medium. Lipid extracts were subjected to TLC and it was determined that the SAA-induced decrease in [(14)C]acetate incorporation into lipids was attributable to decreases in cholesterol, phospholipid and triglyceride levels. The accumulated mass of cholesterol and phospholipid in SAA-treated cultures was significantly less than that of controls, with no change in the accumulated protein. Moreover, SAA had no effect on either protein synthesis or DNA synthesis, suggesting that SAA specifically alters lipid synthesis. By using a peptide corresponding to the cholesterol-binding domain of acute-phase SAA (amino acids 1-18), it was shown that this region of the molecule was as effective as the full-length protein in decreasing lipid synthesis and the accumulation of cholesterol and phospholipid. The implications of these findings for atherosclerosis and Alzheimer's disease are discussed. PMID:10548527

  5. Monocyte-expressed urokinase regulates human vascular smooth muscle cell migration in a coculture model.

    PubMed

    Kusch, Angelika; Tkachuk, Sergey; Lutter, Steffen; Haller, Hermann; Dietz, Rainer; Lipp, Martin; Dumler, Inna

    2002-01-01

    Interactions of vascular smooth muscle cells (VSMC) with monocytes recruited to the arterial wall at a site of injury, with resultant modulation of VSMC growth and migration, are central to the development of vascular intimal thickening. Urokinase-type plasminogen activator (uPA) expressed by monocytes is a potent chemotactic factor for VSMC and might serve for the acceleration of vascular remodeling. In this report, we demonstrate that coculture of human VSMC with freshly isolated peripheral blood-derived human monocytes results in significant VSMC migration that increases during the coculture period. Accordingly, VSMC adhesion was inhibited with similar kinetics. VSMC proliferation, however, was not affected and remained at the same basal level during the whole period of coculture. The increase of VSMC migration in coculture was equivalent to the uPA-induced migration of monocultured VSMC and was blocked by addition into coculture of soluble uPAR (suPAR). Analysis of uPA and uPAR expression in cocultured cells demonstrated that monocytes are a major source of uPA, whose expression increases in coculture five-fold, whereas VSMC display an increased expression of cell surface-associated uPAR. These findings indicate that upregulated uPA production by monocytes following vascular injury acts most likely as an endogenous activator of VSMC migration contributing to the remodeling of vessel walls.

  6. Chrysin inhibits human airway smooth muscle cells proliferation through the extracellular signal-regulated kinase 1/2 signaling pathway.

    PubMed

    Yao, Jing; Zhang, Yun-Shi; Feng, Gan-Zhu; Du, Qiang

    2015-11-01

    Asthma is a chronic airway inflammatory disease characterized by an increased mass of airway smooth muscle (ASM). Chrysin (5,7-dihydroxyflavone), a natural flavonoid, has been shown to exert multiple biological activities, including anti-inflammatory, anti-proliferative and anti-oxidant effects, as well as the potency to ameliorate asthma in animal models. The objective of the present study was to identify the underlying mechanism of the therapeutic effects of chrysin. The impact of chrysin on basal and platelet-derived growth factor (PDGF)-induced proliferation and apoptosis of human airway smooth muscle cells (HASMCs) was investigated. Furthermore, the activation of the extracellular signal-regulated protein kinase (ERK) signaling pathway was evaluated in HASMCs. The results revealed that chrysin significantly inhibited basal as well as PDGF-induced HASMC proliferation, most likely through the suppression of ERK1/2 phosphorylation. However, chrysin did not significantly reduce PDGF-induced apoptosis of HASMCs. The present study indicated that chrysin may be a promising medication for controlling airway remodeling and clinical manifestations of asthma.

  7. The alternative splicing program of differentiated smooth muscle cells involves concerted non-productive splicing of post-transcriptional regulators

    PubMed Central

    Llorian, Miriam; Gooding, Clare; Bellora, Nicolas; Hallegger, Martina; Buckroyd, Adrian; Wang, Xiao; Rajgor, Dipen; Kayikci, Melis; Feltham, Jack; Ule, Jernej; Eyras, Eduardo; Smith, Christopher W.J.

    2016-01-01

    Alternative splicing (AS) is a key component of gene expression programs that drive cellular differentiation. Smooth muscle cells (SMCs) are important in the function of a number of physiological systems; however, investigation of SMC AS has been restricted to a handful of events. We profiled transcriptome changes in mouse de-differentiating SMCs and observed changes in hundreds of AS events. Exons included in differentiated cells were characterized by particularly weak splice sites and by upstream binding sites for Polypyrimidine Tract Binding protein (PTBP1). Consistent with this, knockdown experiments showed that that PTBP1 represses many smooth muscle specific exons. We also observed coordinated splicing changes predicted to downregulate the expression of core components of U1 and U2 snRNPs, splicing regulators and other post-transcriptional factors in differentiated cells. The levels of cognate proteins were lower or similar in differentiated compared to undifferentiated cells. However, levels of snRNAs did not follow the expression of splicing proteins, and in the case of U1 snRNP we saw reciprocal changes in the levels of U1 snRNA and U1 snRNP proteins. Our results suggest that the AS program in differentiated SMCs is orchestrated by the combined influence of auxiliary RNA binding proteins, such as PTBP1, along with altered activity and stoichiometry of the core splicing machinery. PMID:27317697

  8. Transcription of G-protein coupled receptors in corporal smooth muscle is regulated by sialorphin (an endogenous neutral endopeptidase inhibitor)

    PubMed Central

    Tong, Yuehong; Tiplitsky, Scott I.; Tar, Moses; Melman, Arnold; Davies, Kelvin P.

    2009-01-01

    Purpose Several reports have suggested the rat Vcsa1 gene is down-regulated in models of erectile dysfunction (ED). Vcsa’s protein product, sialorphin, is an endogenous neutral endopeptidase (NEP), and its down-regulation could result in prolonged activation of G-protein activated signaling pathways by their peptide agonists. We investigated if down- regulation of Vcsa1 could result in adaptive change in the expression of G-protein coupled receptors (GPCR). Materials and Methods Gene expression in cultured rat corporal smooth muscle cells (CSM) following treatment with siRNA directed against Vcsa1 or the NEP gene was analyzed using microarray and quantitative RT-PCR. In rats Vcsa1 is one of the most down-regulated genes following bilateral transection of the cavernosal nerves. Using that animal model, we also investigated whether the down-regulation of Vcsa1 is accompanied by similar changes in gene expression observed in the CSM cells where Vcsa1 was knocked-down in vitro. Results Microarray analysis and quantitative RT-PCR demonstrated that CSM cells treated in vitro with siRNA against Vcsa1 resulted in up-regulation of GPCR as a functional group. In contrast, treatment of CSM cells that lowered NEP activity resulted in decreases in GPCR expression. These results suggest that the peptide product of Vcsa1, sialorphin, can effect GPCR expression by acting on NEP. In animals with bilaterally transected cavernous nerves the reduced expression of Vcsa1 is accompanied by increased GPCR expression in cavernosal tissue. Conclusions These experiments suggest that the mechanism by which Vcsa1 modulates erectile function is partly mediated through changes in GPCR expression. PMID:18554633

  9. Focal adhesion kinase regulates smooth muscle cell recruitment to the developing vasculature

    PubMed Central

    Cheng, Zhaokang; Sundberg-Smith, Liisa J.; Mangiante, Lee E.; Sayers, Rebecca L.; Hakim, Zeenat S.; Musunuri, Srilaxmi; Maguire, Colin T.; Majesky, Mark W.; Zhou, Zhigang; Mack, Christopher P.; Taylor, Joan M.

    2011-01-01

    Objective The investment of newly formed endothelial cell tubes with differentiated smooth muscle cells (SMC) is critical for appropriate vessel formation, but the underlying mechanisms remain unknown. We previously showed that depletion of focal adhesion kinase (FAK) in the nkx2.5 expression domain led to aberrant outflow tract (OFT) morphogenesis and strove herein to determine the cell types and mechanisms involved. Methods and Results We crossed fakloxp targeted mice with available Cre drivers to deplete FAK in OFT SMC (FAKwnt and FAKnk) or coronary SMC (FAKcSMC). In each case, depletion of FAK led to defective vasculogenesis that was incompatible with post-natal life. Immunohistochemical analysis of the mutant vascular structures revealed that FAK was not required for progenitor cell proliferation, survival, or differentiation into SMC, but was necessary for subsequent SMC recruitment to developing vasculature. Using a novel FAK-null SMC culture model, we found that depletion of FAK did not influence SMC growth or survival, but blocked directional SMC motility and invasion toward the potent endothelial-derived chemokine, PDGFBB. FAK depletion resulted in un-stable lamellipodial protrusions due to defective spatial-temporal activation of the small GTPase, Rac-1 and lack of Rac1-dependent recruitment of cortactin (an actin stabilizing protein) to the leading edge. Moreover, FAK null SMC exhibited a significant reduction in PDGF-stimulated extracellular matrix degradation. Conclusions FAK drives PDGFBB-stimulated SMC chemotaxis/invasion and is essential for SMC to appropriately populate the aorticopulmonary septum and the coronary vascular plexus. PMID:21757658

  10. CDKN2B Regulates TGFβ Signaling and Smooth Muscle Cell Investment of Hypoxic Neovessels

    PubMed Central

    Nanda, Vivek; Downing, Kelly P.; Ye, Jianqin; Xiao, Sophia; Kojima, Yoko; Spin, Joshua M.; DiRenzo, Daniel; Nead, Kevin T.; Connolly, Andrew J; Dandona, Sonny; Perisic, Ljubica; Hedin, Ulf; Maegdefessel, Lars; Dalman, Jessie; Guo, Liang; Zhao, XiaoQing; Kolodgie, Frank D.; Virmani, Renu; Davis, Harry R.; Leeper, Nicholas J.

    2015-01-01

    Rationale Genetic variation at the chromosome 9p21 cardiovascular risk locus has been associated with peripheral artery disease (PAD), but its mechanism remains unknown. Objective To determine whether this association is secondary to an increase in atherosclerosis, or is the result of a separate angiogenesis-related mechanism. Methods and Results Quantitative evaluation of human vascular samples revealed that carriers of the 9p21 risk allele possess a significantly higher burden of immature intraplaque microvessels than carriers of the ancestral allele, irrespective of lesion size or patient comorbidity. To determine whether aberrant angiogenesis also occurs under non-atherosclerotic conditions, we performed femoral artery ligation surgery in mice lacking the 9p21 candidate gene, Cdkn2b. These animals developed advanced hind-limb ischemia and digital auto-amputation, secondary to a defect in the capacity of the Cdkn2b-deficient smooth muscle cell (SMC) to support the developing neovessel. Microarray studies identified impaired TGFβ signaling in cultured CDKN2B-deficient cells, as well as TGFβ1 upregulation in the vasculature of 9p21 risk allele carriers. Molecular signaling studies indicated that loss of CDKN2B impairs the expression of the inhibitory factor, SMAD-7, which promotes downstream TGFβ activation. Ultimately, this manifests in the upregulation of a poorly studied effector molecule, TGFβ1-induced-1, which is a TGFβ-‘rheostat’ known to have antagonistic effects on the EC and SMC. Dual knockdown studies confirmed the reversibility of the proposed mechanism, in vitro. Conclusions These results suggest that loss of CDKN2B may not only promote cardiovascular disease through the development of atherosclerosis, but may also impair TGFβ signaling and hypoxic neovessel maturation. PMID:26596284

  11. Regulation of oxytocin receptor responsiveness by G protein-coupled receptor kinase 6 in human myometrial smooth muscle.

    PubMed

    Willets, Jonathon M; Brighton, Paul J; Mistry, Rajendra; Morris, Gavin E; Konje, Justin C; Challiss, R A John

    2009-08-01

    Oxytocin plays an important role in the progression, timing, and modulation of uterine contraction during labor and is widely used as an uterotonic agent. We investigated the mechanisms regulating oxytocin receptor (OTR) signaling in human primary myometrial smooth muscle cells and the ULTR cell-line. Oxytocin produced concentration-dependent increases in both total [(3)H]inositol phosphate accumulation and intracellular Ca(2+) concentration ([Ca(2+)](i)); however, responses were greater and more reproducible in the ULTR cell line. Assessment of phospholipase C activity in single cells revealed that the OTR desensitizes rapidly (within 5 min) in the presence of oxytocin (100 nm). To characterize OTR desensitization further, cells were stimulated with a maximally effective concentration of oxytocin (100 nm, 30 sec) followed by a variable washout period and a second identical application of oxytocin. This brief exposure to oxytocin caused a marked decrease (>70%) in OTR responsiveness to rechallenge and was fully reversed by increasing the time period between agonist challenges. To assess involvement of G protein-coupled receptor kinases (GRKs) in OTR desensitization, cells were transfected with small interfering RNAs to cause specific > or =75% knockdown of GRKs 2, 3, 5, or 6. In both primary myometrial and ULTR cells, knockdown of GRK6 largely prevented oxytocin-induced OTR desensitization; in contrast, selective depletion of GRKs 2, 3, or 5 was without effect. These data indicate that GRK6 recruitment is a cardinal effector of OTR responsiveness and provide mechanistic insight into the likely in vivo regulation of OTR signaling in uterine smooth muscle.

  12. β1-Subunit of the Ca2+-activated K+ channel regulates contractile activity of mouse urinary bladder smooth muscle

    PubMed Central

    Petkov, Georgi V; Bonev, Adrian D; Heppner, Thomas J; Brenner, Robert; Aldrich, Richard W; Nelson, Mark T

    2001-01-01

    The large-conductance calcium-activated potassium (BK) channel plays an important role in controlling membrane potential and contractility of urinary bladder smooth muscle (UBSM). These channels are composed of a pore-forming α-subunit and an accessory, smooth muscle-specific, β1-subunit. Our aim was to determine the functional role of the β1-subunit of the BK channel in controlling the contractions of UBSM by using BK channel β1-subunit ‘knock-out’ (KO) mice. The β-galactosidase reporter (lacZ gene) was targeted to the β1 locus, which provided the opportunity to examine the expression of the β1-subunit in UBSM. Based on this approach, the β1-subunit is highly expressed in UBSM. BK channels lacking β1-subunits have reduced activity, consistent with a shift in BK channel voltage/Ca2+ sensitivity. Iberiotoxin, an inhibitor of BK channels, increased the amplitude and decreased the frequency of phasic contractions of UBSM strips from control mice. The effects of the β1-subunit deletion on contractions were similar to the effect of iberiotoxin on control mice. The UBSM strips from β1-subunit KO mice had elevated phasic contraction amplitude and decreased frequency when compared to control UBSM strips. Iberiotoxin increased the amplitude and frequency of phasic contractions, and UBSM tone of UBSM strips from β1-subunit KO mice, suggesting that BK channels still regulate contractions in the absence of the β1-subunit. The results indicate that the β1-subunit, by modulating BK channel activity, plays a significant role in the regulation of phasic contractions of the urinary bladder. PMID:11731577

  13. Role of integrin-linked kinase in vascular smooth muscle cells: Regulation by statins and angiotensin II

    SciTech Connect

    Friedrich, Erik B. . E-mail: efriedrich@med-in.uni-sb.de; Clever, Yvonne P.; Wassmann, Sven; Werner, Nikos; Boehm, Michael; Nickenig, Georg

    2006-10-27

    Our goal was to characterize the role of integrin-linked kinase (ILK) in vascular smooth muscle cells (VSMC), which play a crucial role in atherogenesis. Transfection of VSMC with wild-type and dominant-negative ILK cDNA constructs revealed that ILK mediates migration and proliferation of VSMC but has no effect on VSMC survival. The pro-atherogenic mediator angiotensin II increases ILK protein expression and kinase activity while statin treatment down-regulates ILK in VSMC. Functionally, ILK is necessary for angiotensin II-mediated VSMC migration and proliferation. In VSMC transduced with dominant-negative ILK, statins mediate an additive inhibition of VSMC migration and proliferation, while transfection with wild-type ILK is sufficient to overcome the inhibitory effects of statin treatment on VSMC migration and proliferation. In vivo, ILK is expressed in VSMC of aortic sections from wild-type mice where it is down-regulated following statin treatment and up-regulated following induction of atherosclerosis in apoE-/- mice. These data identify ILK as a novel target in VSMC for anti-atherosclerotic therapy.

  14. MicroRNA-214 regulates smooth muscle cell differentiation from stem cells by targeting RNA-binding protein QKI.

    PubMed

    Wu, Yutao; Li, Zhoubin; Yang, Mei; Dai, Bing; Hu, Feng; Yang, Feng; Zhu, Jianhua; Chen, Ting; Zhang, Li

    2017-02-08

    MicroRNA-214(miR-214) has been recently reported to regulate angiogenesis and embryonic stem cells (ESCs) differentiation. However, very little is known about its functional role in vascular smooth muscle cells (VSMCs) differentiation from ESCs. In the present study, we assessed the hypothesis that miR-214 and its target genes play an important role in VSMCs differentiation. Murine ESCs were seeded on collagen-coated flasks and cultured in differentiation medium for 2 to 8 days to allow VSMCs differentiation. miR-214 was significantly upregulated during VSMCs differentiation. miR-214 overexpression and knockdown in differentiating ESCs significantly promoted and inhibited VSMCs -specific genes expression, respectively. Importantly, miR-214 overexpression in ESCs promoted VSMCs differentiation in vivo. Quaking (QKI) was predicted as one of the major targets of miR-214, which was negatively regulated by miR-214. Luciferase assay showed miR-214 substantially inhibited wild type, but not the mutant version of QKI-3-UTR-luciferase activity in differentiating ESCs, further confirming a negative regulation role of miR-214 in QKI gene expression. Mechanistically, our data showed that miR-214 regulated VSMCs gene expression during VSMCs differentiation from ESCs through suppression of QKI. We further demonstrated that QKI down-regulated the expression of SRF, MEF2C and Myocd through transcriptional repression and direct binding to promoters of the SRF, MEF2c and Myocd genes. Taken together, we have uncovered a central role of miR-214 in ESC-VSMC differentiation, and successfully identified QKI as a functional modulating target in miR-214 mediated VSMCs differentiation.

  15. Platelet-derived growth factor regulates vascular smooth muscle phenotype via mammalian target of rapamycin complex 1

    SciTech Connect

    Ha, Jung Min; Yun, Sung Ji; Kim, Young Whan; Jin, Seo Yeon; Lee, Hye Sun; Song, Sang Heon; Shin, Hwa Kyoung; Bae, Sun Sik

    2015-08-14

    Mammalian target of rapamycin complex (mTORC) regulates various cellular processes including proliferation, growth, migration and differentiation. In this study, we showed that mTORC1 regulates platelet-derived growth factor (PDGF)-induced phenotypic conversion of vascular smooth muscle cells (VSMCs). Stimulation of contractile VSMCs with PDGF significantly reduced the expression of contractile marker proteins in a time- and dose-dependent manner. In addition, angiotensin II (AngII)-induced contraction of VSMCs was completely blocked by the stimulation of VSMCs with PDGF. PDGF-dependent suppression of VSMC marker gene expression was significantly blocked by inhibition of phosphatidylinositol 3-kinase (PI3K), extracellular signal-regulated kinase (ERK), and mTOR whereas inhibition of p38 MAPK had no effect. In particular, inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked the PDGF-dependent phenotypic change of VSMCs whereas silencing of Rictor had no effect. In addition, loss of AngII-dependent contraction by PDGF was significantly retained by silencing of Raptor. Inhibition of mTORC1 by rapamycin or by silencing of Raptor significantly blocked PDGF-induced proliferation of VSMCs. Taken together, we suggest that mTORC1 plays an essential role in PDGF-dependent phenotypic changes of VSMCs. - Graphical abstract: Regulation of VSMC phenotype by PDGF-dependent activation of mTORC1. - Highlights: • The expression of contractile marker proteins was reduced by PDGF stimulation. • PDGF-dependent phenotypic conversion of VSMCs was blocked by inhibition of mTOR. • PDGF-induced proliferation of VSMCs was attenuated by inhibition of mTORC1. • mTORC1 plays a critical role in PDGF-dependent phenotypic conversion of VSMCs.

  16. Cinnamon and its Components Suppress Vascular Smooth Muscle Cell Proliferation by Up-Regulating Cyclin-Dependent Kinase Inhibitors.

    PubMed

    Kwon, Hyeeun; Lee, Jung-Jin; Lee, Ji-Hye; Cho, Won-Kyung; Gu, Min Jung; Lee, Kwang Jin; Ma, Jin Yeul

    2015-01-01

    Cinnamomum cassia bark has been used in traditional herbal medicine to treat a variety of cardiovascular diseases. However, the antiproliferative effect of cinnamon extract on vascular smooth muscle cells (VSMCs) and the corresponding restenosis has not been explored. Hence, after examining the effect of cinnamon extract on VSMC proliferation, we investigated the possible involvement of signal transduction pathways associated with early signal and cell cycle analysis, including regulatory proteins. Besides, to identify the active components, we investigated the components of cinnamon extract on VSMC proliferation. Cinnamon extract inhibited platelet-derived growth factor (PDGF)-BB-induced VSMC proliferation and suppressed the PDGF-stimulated early signal transduction. In addition, cinnamon extract arrested the cell cycle and inhibited positive regulatory proteins. Correspondingly, the protein levels of p21 and p27 not only were increased in the presence of cinnamon extract, also the expression of proliferating cell nuclear antigen (PCNA) was inhibited by cinnamon extract. Besides, among the components of cinnamon extract, cinnamic acid (CA), eugenol (EG) and cinnamyl alcohol significantly inhibited the VSMC proliferation. Overall, the present study demonstrates that cinnamon extract inhibited the PDGF-BB-induced proliferation of VSMCs through a G0/G1 arrest, which down-regulated the expression of cell cycle positive regulatory proteins by up-regulating p21 and p27 expression.

  17. Fibroblast growth factor (FGF) signaling regulates transforming growth factor beta (TGFβ)-dependent smooth muscle cell phenotype modulation

    PubMed Central

    Chen, Pei-Yu; Qin, Lingfeng; Li, Guangxin; Tellides, George; Simons, Michael

    2016-01-01

    Smooth muscle cells (SMCs) in normal blood vessels exist in a highly differentiate state characterized by expression of SMC-specific contractile proteins (“contractile phenotype”). Following blood vessel injury in vivo or when cultured in vitro in the presence of multiple growth factors, SMC undergo a phenotype switch characterized by the loss of contractile markers and appearance of expression of non-muscle proteins (“proliferative phenotype”). While a number of factors have been reported to modulate this process, its regulation remains uncertain. Here we show that induction of SMC FGF signaling inhibits TGFβ signaling and converts contractile SMCs to the proliferative phenotype. Conversely, inhibition of SMC FGF signaling induces TGFβ signaling converting proliferating SMCs to the contractile phenotype, even in the presence of various growth factors in vitro or vascular injury in vivo. The importance of this signaling cross-talk is supported by in vivo data that show that an SMC deletion of a pan-FGF receptor adaptor Frs2α (fibroblast growth factor receptor substrate 2 alpha) in mice profoundly reduces neointima formation and vascular remodelling following carotid artery ligation. These results demonstrate that FGF-TGFβ signaling antagonism is the primary regulator of the SMC phenotype switch. Manipulation of this cross-talk may be an effective strategy for treatment of SMC-proliferation related diseases. PMID:27634335

  18. HSP70 increases extracellular matrix production by human vascular smooth muscle through TGF-β1 up-regulation.

    PubMed

    González-Ramos, Marta; Calleros, Laura; López-Ongil, Susana; Raoch, Viviana; Griera, Mercedes; Rodríguez-Puyol, Manuel; de Frutos, Sergio; Rodríguez-Puyol, Diego

    2013-02-01

    The circulating levels of heat shock proteins (HSP) are increased in cardiovascular diseases; however, the implication of this for the fibrotic process typical of such diseases remains unclear. HSP70 can interact with the vascular smooth muscle cells (SMC), the major producer of extracellular matrix (ECM) proteins, through the Toll-like receptors 4 (TLR4). The transforming growth factor type-β1 (TGF-β1) is a well known vascular pro-fibrotic cytokine that is regulated in part by AP-1-dependent transcriptional mechanisms. We hypothesized that extracellular HSP70 could interact with SMCs, inducing TGF-β1 synthesis and subsequent changes in the vascular ECM. We demonstrate that extracellular HSP70 binds to human aorta SMC TLR4, which up-regulates the AP-1-dependent transcriptional activity of the TGF-β1 promoter. This is achieved through the mitogen activated protein kinases JNK and ERK, as demonstrated by the use of specific blockers and the knockdown of TLR4 with specific small interfering RNAs. The TGF-β1 upregulation increase the expression of the ECM proteins type I collagen and fibronectin. This novel observation may elucidate the mechanisms by which HSP70 contributes in the inflammation and fibrosis present in atherosclerosis and other fibrosis-related diseases.

  19. MicroRNAs 29b, 133b, and 211 Regulate Vascular Smooth Muscle Calcification Mediated by High Phosphorus.

    PubMed

    Panizo, Sara; Naves-Díaz, Manuel; Carrillo-López, Natalia; Martínez-Arias, Laura; Fernández-Martín, José Luis; Ruiz-Torres, María Piedad; Cannata-Andía, Jorge B; Rodríguez, Isabel

    2016-03-01

    Vascular calcification is a frequent cause of morbidity and mortality in patients with CKD and the general population. The common association between vascular calcification and osteoporosis suggests a link between bone and vascular disorders. Because microRNAs (miRs) are involved in the transdifferentiation of vascular smooth muscle cells into osteoblast-like cells, we investigated whether miRs implicated in osteoblast differentiation and bone formation are involved in vascular calcification. Different levels of uremia, hyperphosphatemia, and aortic calcification were induced by feeding nephrectomized rats a normal or high-phosphorus diet for 12 or 20 weeks, at which times the levels of eight miRs (miR-29b, miR-125, miR-133b, miR-135, miR-141, miR-200a, miR-204, and miR-211) in the aorta were analyzed. Compared with controls and uremic rats fed a normal diet, uremic rats fed a high-phosphorous diet had lower levels of miR-133b and miR-211 and higher levels of miR-29b that correlated respectively with greater expression of osteogenic RUNX2 and with lower expression of several inhibitors of osteoblastic differentiation. Uremia per se mildly reduced miR-133b levels only. Similar results were obtained in two in vitro models of vascular calcification (uremic serum and high-calcium and -phosphorus medium), and experiments using antagomirs and mimics to modify miR-29b, miR-133b, and miR-211 expression levels in these models confirmed that these miRs regulate the calcification process. We conclude that miR-29b, miR-133b, and miR-211 have direct roles in the vascular smooth muscle calcification induced by high phosphorus and may be new therapeutic targets in the management of vascular calcification.

  20. Externally applied cyclic strain regulates localization of focal contact components in cultured smooth muscle cells.

    PubMed

    Cunningham, James J; Linderman, Jennifer J; Mooney, David J

    2002-01-01

    Mechanical signals are critical regulators of cellular gene expression, yet little is understood of the mechanism whereby cells sense mechanical forces. In this study we have tested the hypothesis that mechanical strain applied to populations of cells via their adhesion substrate rapidly alters the cellular distribution of focal contact proteins. Focal contact-associated components (vinculin, a-actinin, paxillin) were assayed by immunofluorescence microscopy and quantitative western blotting. Application of a single step increase in strain in multiple experiments caused overall a small change in focal contact-associated vinculin. In contrast, cyclic strain induced a large and very reproducible increase in detergent-insoluble vinculin (52% relative to static) after just 1 min of strain. Insoluble paxillin was transiently enriched with a similar time course, whereas insoluble a-actinin did not change significantly in response to cyclic strain. Rhodamine-labeled chicken vinculin added to permeabilized cells preferentially localized to focal contacts in response to cyclic strain, but not a single step increase in strain. These findings establish that insoluble levels of focal contact components are altered rapidly following application of an appropriate number of mechanical perturbations, and suggest that at least one component of the mechanism does not involve soluble intermediates.

  1. Integrin α3 blockade enhances microtopographical down-regulation of α-smooth muscle actin: role of microtopography in ECM regulation.

    PubMed

    Ayala, Perla; Desai, Tejal A

    2011-07-01

    Development of functional engineered matrices for regenerative therapies can benefit from an understanding of how physical cues at the microscale affect cell behavior. In this work, we use microfabricated systems to study how stiffness and microscale topographical cues in the form of "micropegs" affect extracellular matrix synthesis. Previous work from our lab has shown that microtopographical cues in 2D and 3D systems decrease cellular proliferation and regulate matrix synthesis. In this work, the combined role of stiffness and topography on ECM synthesis is investigated in a 2D micropeg system. These studies show that fibroblasts cultured on polydimethylsiloxane (PDMS) substrates with micropegs have reduced expression of collagen type I (Col I) and collagen type VI (Col VI) compared to fibroblasts cultured on flat substrates. In addition, cells on micropegged substrates exhibit down-regulation of other important regulators of ECM synthesis such as α-smooth muscle actin (α-SMA), and integrin α3 (Int α3). Interestingly, this effect is dependent on the contractility and adhesion of the cells. When cultured in the presence of RhoA kinase (ROCK) and myosin light chain kinase (MLCK) inhibitors, no significant differences in the expression of collagen, α-SMA, Int α3, and TGFB1 are observed. Additionally, disruptions in cell adhesion prevent microtopographical regulation of ECM synthesis. When using an antibody to block the extracellular domain of Int α3, no differences in the expression of collagen are observed and blocking Int α3 results in enhanced down-regulation of α-SMA on the stiffer micropegged substrates. These findings demonstrate that regulation of extracellular matrix production by cells on a synthetic substrate can be guided via physical cues at the microscale, and add to the body of knowledge on the role of integrin-mediated mechanotransduction.

  2. Magnesium regulates intracellular ionized calcium concentration and cell geometry in vascular smooth muscle cells (VSMC)

    SciTech Connect

    Zhang, A.; Cheng, T.P.; Altura, B.M. )

    1991-03-11

    It has been suggested that the extracellular Mg{sup 2+} may modulate contractility of VSMC by controlling the cellular level of free Ca{sup 2+}. The present studies were designed to determine the effects of (Mg{sup 2+}) on the distribution of intracellular free Ca{sup 2+} using digital imaging fluorescence microscopy of Fura-2 fluorescence of single VSMC cultured from rat aortas. When incubated with HEPES buffer solution containing 1.2mM Mg{sup 2+}, the myocytes are spindle-shaped, and the basal level of (Ca{sup 2+}){sub i} estimated from the ratio (F340/F380) is 96.6 {plus minus} 7.9nM with a heterogeneous distribution. (Mg{sup 2+}){sub o} withdrawal from the incubation medium induces consistently a dramatic increment of (Ca{sup 2+}){sub i} up to 579.6 {plus minus} 39.3nM, about a 5.8-fold elevation compared to control experiments. Similarly, lowering (Mg{sup 2+}){sub o} to 0.3mM (the lowest physiological range) elevates (Ca{sup 2+}){sub i} to the intermediate level of 348.0 {plus minus} 31.5nM. However, the heterogeneous distribution of (Ca{sup 2+}){sub i} is still evident when (Mg{sup 2+}){sub o} is lowered. Simultaneously to the (Ca{sup 2+}){sub i} increments, cell shapes were changed. In contrast, elevation of (Mg{sup 2+}){sub o} to 4.8mM was found to decrease (Ca{sup 2+}){sub i} to 72.0 {plus minus} 4.6nM. Removal of (Ca{sup 2+}){sub o}, however, abolished the increments of (Ca{sup 2+}){sub i} induced by (Mg{sup 2+}){sub o} withdrawal. These results demonstrate that (Mg{sup 2+}){sub o} regulated (Ca{sup 2+}){sub i} and geometry of VSMC, probably through controlling plasma membrane permeability to Ca{sup 2+}.

  3. Transdifferentiation of pulmonary arteriolar endothelial cells into smooth muscle-like cells regulated by myocardin involved in hypoxia-induced pulmonary vascular remodelling

    PubMed Central

    Zhu, Pengcheng; Huang, Lei; Ge, Xiaona; Yan, Fei; Wu, Renliang; Ao, Qilin

    2006-01-01

    Myocardin gene has been identified as a master regulator of smooth muscle cell differentiation. Smooth muscle cells play a critical role in the pathogenesis of hypoxia-induced pulmonary hypertension (PH) and pulmonary vascular remodelling (PVR). The purpose of this study was to investigate the change of myocardin gene expression in the pulmonary vessels of hypoxia-induced PH affected by Sildenafil treatment and the involvement of endothelial cells transdifferentiation into smooth muscle cells in the process of hypoxia-induced PH and PVR. Myocardin and relative markers were investigated in animal models and cultured endothelial cells. Mean pulmonary artery pressure (mPAP) was measured. Immunohistochemistry and immunofluorescence were used to show the expression of smooth muscle α-actin (SMA), in situ hybridization (ISH) and reverse transcription polymerase chain reaction (RT-PCR) were performed respectively to detect the myocardin and SMA expression at mRNA levels. Small interfering RNA (siRNA) induced suppression of myocardin in cultured cells. We confirmed that hypoxia induced the PH and PVR in rats. Sildenafil could attenuate the hypoxia-induced PH. We found that myocardin mRNA expression is upregulated significantly in the hypoxic pulmonary vessels and cultured cells but downregulated in PH with Sildenafil treatment. The porcine pulmonary artery endothelial cells (PAECs) transdifferentiate into smooth muscle-like cells in hypoxic culture while the transdifferentiation did not occur when SiRNA of myocardin was applied. Our results suggest that myocardin gene, as a marker of smooth muscle cell differentiation, was expressed in the pulmonary vessels in hypoxia-induced PH rats, which could be downregulated by Sildenafil treatment, as well as in hypoxic cultured endothelial cells. Hypoxia induced the transdifferentiation of endothelial cells of vessels into smooth muscle-like cells which was regulated by myocardin. PMID:17222214

  4. Endogenous IGF-I and alpha v beta3 integrin ligands regulate increased smooth muscle growth in TNBS-induced colitis.

    PubMed

    Hazelgrove, Krystina B; Flynn, Robert S; Qiao, Li-Ya; Grider, John R; Kuemmerle, John F

    2009-06-01

    Endogenous insulin-like growth factor-I (IGF-I) regulates intestinal smooth muscle growth by concomitantly stimulating proliferation and inhibiting apoptosis. IGF-I-stimulated growth is augmented by the alpha(v)beta(3) integrin ligands vitronectin and fibronectin. IGF-I expression in smooth muscle is increased in both TNBS-induced colitis and Crohn's disease. We hypothesized that intestinal inflammation increased vitronectin and fibronectin expression by smooth muscle and, along with IGF-I upregulation, increased intestinal muscle growth. Intestinal smooth muscle cells were examined 7 days following the induction of TNBS-induced colitis. Although alpha(v)beta(3) integrin expression was not altered by TNBS-induced colitis, vitronectin and fibronectin levels were increased by 80 +/- 10% and 90 +/- 15%, above control levels, respectively. Basal IGF-I receptor phosphorylation in inflamed muscle from TNBS-treated rats was increased by 86 +/- 8% over vehicle-treated controls. Basal ERK1/2, p70S6 kinase, and GSK-3beta phosphorylation in muscle cells of TNBS-treated rats were also increased by 140-180%. TNBS treatment increased basal muscle cell proliferation by 130 +/- 15% and decreased apoptosis by 20 +/- 2% compared with that in vehicle-treated controls. The changes in proliferation and apoptosis were reversed by an IGF-I receptor tyrosine kinase inhibitor or an alpha(v)beta(3) integrin antagonist. The results suggest that smooth muscle hyperplasia in TNBS-induced colitis partly results from the upregulation of endogenous IGF-I and ligands of alpha(v)beta(3) integrin that mediate increased smooth muscle cell proliferation and decreased apoptosis. This paper has identified one mechanism regulating smooth muscle hyperplasia, a feature of stricture formation that occurs in the chronically inflamed intestine of TNBS-induced colitis and potentially Crohn's disease.

  5. Signal-transduction pathways that regulate smooth muscle function I. Signal transduction in phasic (esophageal) and tonic (gastroesophageal sphincter) smooth muscles.

    PubMed

    Harnett, Karen M; Cao, Weibiao; Biancani, Piero

    2005-03-01

    Contraction of esophageal (Eso) and lower esophageal sphincter (LES) circular muscle depends on distinct signal-transduction pathways. ACh-induced contraction of Eso muscle is linked to phosphatidylcholine metabolism, production of diacylglycerol and arachidonic acid (AA), and activation of the Ca(2+)-insensitive PKCepsilon. Although PKCepsilon does not require Ca(2+) for activation, either influx of extracellular Ca(2+) or release of Ca(2+) from stores is needed to activate the phospholipases responsible for hydrolysis of membrane phospholipids and production of second messengers, which activate PKCepsilon. In contrast, the LES uses two distinct intracellular pathways: 1) a PKC-dependent pathway activated by low doses of agonists or during maintenance of spontaneous tone, and 2) a Ca(2+)-calmodulin-myosin light chain kinase (MLCK)-dependent pathway activated in response to maximally effective doses of agonists during the initial phase of contraction. The Ca(2+) levels, released by agonist-induced activity of phospholipase C, determine which contractile pathway is activated in the LES. The Ca(2+)-calmodulin-MLCK-dependent contractile pathway has been well characterized in a variety of smooth muscles. The steps linking activation of PKC to myosin light chain (MLC20) phosphorylation and contraction, however, have not been clearly defined for LES, Eso, or other smooth muscles. In addition, in LES circular muscle, a low-molecular weight pancreatic-like phospholipase A2 (group I PLA2) causes production of AA, which is metabolized to prostaglandins and thromboxanes. These AA metabolites act on receptors linked to heterotrimeric G proteins to induce activation of phospholipases and production of second messengers to maintain contraction of LES circular muscle. We have examined the signal-transduction pathways activated by PGF(2alpha) and by thromboxane analogs during the initial contractile phase and found that these pathways are the same as those activated by other

  6. Regulation of proliferation and gene expression in cultured human aortic smooth muscle cells by resveratrol and standardized grape extracts

    SciTech Connect

    Wang Zhirong; Chen Yan; Labinskyy, Nazar; Hsieh Tzechen; Ungvari, Zoltan; Wu, Joseph M. . E-mail: Joseph_Wu@nymc.edu

    2006-07-21

    Epidemiologic studies suggest that low to moderate consumption of red wine is inversely associated with the risk of coronary heart disease; the protection is in part attributed to grape-derived polyphenols, notably trans-resveratrol, present in red wine. It is not clear whether the cardioprotective effects of resveratrol can be reproduced by standardized grape extracts (SGE). In the present studies, we determined, using cultured human aortic smooth muscle cells (HASMC), growth and specific gene responses to resveratrol and SGE provided by the California Table Grape Commission. Suppression of HASMC proliferation by resveratrol was accompanied by a dose-dependent increase in the expression of tumor suppressor gene p53 and heat shock protein HSP27. Using resveratrol affinity chromatography and biochemical fractionation procedures, we showed by immunoblot analysis that treatment of HASMC with resveratrol increased the expression of quinone reductase I and II, and also altered their subcellular distribution. Growth of HASMC was significantly inhibited by 70% ethanolic SGE; however, gene expression patterns in various cellular compartments elicited in response to SGE were substantially different from those observed in resveratrol-treated cells. Further, SGE also differed from resveratrol in not being able to induce relaxation of rat carotid arterial rings. These results indicate that distinct mechanisms are involved in the regulation of HASMC growth and gene expression by SGE and resveratrol.

  7. Intracellular Acid-extruding regulators and the effect of lipopolysaccharide in cultured human renal artery smooth muscle cells.

    PubMed

    Loh, Shih-Hurng; Lee, Chung-Yi; Tsai, Yi-Ting; Shih, Shou-Jou; Chen, Li-Wei; Cheng, Tzu-Hurng; Chang, Chung-Yi; Tsai, Chein-Sung

    2014-01-01

    Homeostasis of the intracellular pH (pHi) in mammalian cells plays a pivotal role in maintaining cell function. Thus far, the housekeeping Na(+)-H(+) exchanger (NHE) and the Na(+)-HCO3(-) co-transporter (NBC) have been confirmed in many mammalian cells as major acid extruders. However, the role of acid-extruding regulators in human renal artery smooth muscle cells (HRASMCs) remains unclear. It has been demonstrated that lipopolysaccharide (LPS)-induced vascular occlusion is associated with the apoptosis, activating calpain and increased [Ca(2+)]i that are related to NHE1 activity in endothelia cells. This study determines the acid-extruding mechanisms and the effect of LPS on the resting pHi and active acid extruders in cultured HRASMCs. The mechanism of pHi recovery from intracellular acidosis (induced by NH4Cl-prepulse) is determined using BCECF-fluorescence in cultured HRASMCs. It is seen that (a) the resting pHi is 7.19 ± 0.03 and 7.10 ± 0.02 for HEPES- and CO2/HCO3(-)- buffered solution, respectively; (b) apart from the housekeeping NHE1, another Na(+)-coupled HCO3(-) transporter i.e. NBC, functionally co-exists to achieve acid-equivalent extrusion; (c) three different isoforms of NBC: NBCn1 (SLC4A7; electroneutral), NBCe1 (SLC4A4; electrogenic) and NBCe2 (SLC4A5), are detected in protein/mRNA level; and (d) pHi and NHE protein expression/activity are significantly increased by LPS, in both a dose- and time- dependent manner, but NBCs protein expression is not. In conclusion, it is demonstrated, for the first time, that four pHi acid-extruding regulators: NHE1, NBCn1, NBCe1 and NBCe2, co-exist in cultured HRASMCs. LPS also increases cellular growth, pHi and NHE in a dose- and time-dependent manner.

  8. Chronic exposure to fibrin and fibrinogen differentially regulates intracellular Ca2+ in human pulmonary arterial smooth muscle and endothelial cells.

    PubMed

    Firth, Amy L; Yau, Jocelyn; White, Amanda; Chiles, Peter G; Marsh, James J; Morris, Timothy A; Yuan, Jason X-J

    2009-06-01

    Acute pulmonary embolism occurs in more than half a million people a year in the United States. Chronic thromboembolic pulmonary hypertension (CTEPH) develops in approximately 4% of these patients due to unresolved thromboemboli. CTEPH is thus a relatively common, progressive, and potentially fatal disease. One currently proposed theory for the poor resolution advocates that modification of fibrinogen in CTEPH patients causes resistance of emboli to fibrinolysis. The current study investigated the regulation of cytosolic Ca(2+) ([Ca(2+)](cyt)), central to the control of cell migration, proliferation, and contraction, by chronic exposure of pulmonary artery smooth muscle (PASMC) and endothelial (PAEC) cells to fibrinogen and fibrin. Basal [Ca(2+)](cyt) was substantially elevated in PAEC after culture on fibrinogen, fibrin, and thrombin and in PASMC on fibrinogen and fibrin. In PAEC, fibrinogen significantly decreased the peak [Ca(2+)](cyt) transient (P <0.001) without a change in the transient peak width (at 50% of the peak height). This response was independent of effects on the proteinase-activated receptor (PAR) 1. Furthermore, chronic exposure to thrombin, an activator of PAR, significantly reduced the peak agonist-induced Ca(2+) release in PAEC, but increased it in PASMC. The recovery rate of the agonist-induced [Ca(2+)](cyt) transients decelerated in PASMC chronically exposed to fibrin; a small increase of the peak Ca(2+) was also observed. Substantial augmentation of PASMC (but not PAEC) proliferation was observed in response to chronic fibrin exposure. In conclusion, chronic exposure to fibrinogen, fibrin, and thrombin caused differential changes in [Ca(2+)](cyt) in PAEC and PASMC. Such changes in [Ca(2+)](cyt) may contribute to vascular changes in patients who have CTEPH where the pulmonary vasculature is persistently exposed to thromboemboli.

  9. Chronic exposure to fibrin and fibrinogen differentially regulates intracellular Ca2+ in human pulmonary arterial smooth muscle and endothelial cells

    PubMed Central

    Firth, Amy L.; Yau, Jocelyn; White, Amanda; Chiles, Peter G.; Marsh, James J.; Morris, Timothy A.; Yuan, Jason X.-J.

    2009-01-01

    Acute pulmonary embolism occurs in more than half a million people a year in the United States. Chronic thromboembolic pulmonary hypertension (CTEPH) develops in ∼4% of these patients due to unresolved thromboemboli. CTEPH is thus a relatively common, progressive, and potentially fatal disease. One currently proposed theory for the poor resolution advocates that modification of fibrinogen in CTEPH patients causes resistance of emboli to fibrinolysis. The current study investigated the regulation of cytosolic Ca2+ ([Ca2+]cyt), central to the control of cell migration, proliferation, and contraction, by chronic exposure of pulmonary artery smooth muscle (PASMC) and endothelial (PAEC) cells to fibrinogen and fibrin. Basal [Ca2+]cyt was substantially elevated in PAEC after culture on fibrinogen, fibrin, and thrombin and in PASMC on fibrinogen and fibrin. In PAEC, fibrinogen significantly decreased the peak [Ca2+]cyt transient (P <0.001) without a change in the transient peak width (at 50% of the peak height). This response was independent of effects on the proteinase-activated receptor (PAR) 1. Furthermore, chronic exposure to thrombin, an activator of PAR, significantly reduced the peak agonist-induced Ca2+ release in PAEC, but increased it in PASMC. The recovery rate of the agonist-induced [Ca2+]cyt transients decelerated in PASMC chronically exposed to fibrin; a small increase of the peak Ca2+ was also observed. Substantial augmentation of PASMC (but not PAEC) proliferation was observed in response to chronic fibrin exposure. In conclusion, chronic exposure to fibrinogen, fibrin, and thrombin caused differential changes in [Ca2+]cyt in PAEC and PASMC. Such changes in [Ca2+]cyt may contribute to vascular changes in patients who have CTEPH where the pulmonary vasculature is persistently exposed to thromboemboli. PMID:19363122

  10. Voltage-gated K+ channels sensitive to stromatoxin-1 regulate myogenic and neurogenic contractions of rat urinary bladder smooth muscle

    PubMed Central

    Chen, Muyan; Kellett, Whitney F.

    2010-01-01

    Members of the voltage-gated K+ (KV) channel family are suggested to control the resting membrane potential and the repolarization phase of the action potential in urinary bladder smooth muscle (UBSM). Recent studies report that stromatoxin-1, a peptide isolated from tarantulas, selectively inhibits KV2.1, KV2.2, KV4.2, and KV2.1/9.3 channels. The objective of this study was to investigate whether KV channels sensitive to stromatoxin-1 participate in the regulation of rat UBSM contractility and to identify their molecular fingerprints. Stromatoxin-1 (100 nM) increased the spontaneous phasic contraction amplitude, muscle force, and tone in isolated UBSM strips. However, stromatoxin-1 (100 nM) had no effect on the UBSM contractions induced by depolarizing agents such as KCl (20 mM) or carbachol (1 μM). This indicates that, under conditions of sustained membrane depolarization, the KV channels sensitive to stromatoxin-1 have no further contribution to the membrane excitability and contractility. Stromatoxin-1 (100 nM) increased the amplitude of the electrical field stimulation-induced contractions, suggesting also a role for these channels in neurogenic contractions. RT-PCR experiments on freshly isolated UBSM cells showed mRNA expression of KV2.1, KV2.2, and KV9.3, but not KV4.2 channel subunits. Protein expression of KV2.1 and KV2.2 channels was detected using Western blot and was further confirmed by immunocytochemical detection in freshly isolated UBSM cells. These novel findings indicate that KV2.1 and KV2.2, but not KV4.2, channel subunits are expressed in rat UBSM and play a key role in opposing both myogenic and neurogenic UBSM contractions. PMID:20393158

  11. Role of EGFR transactivation in angiotensin II signaling to extracellular regulated kinase in preglomerular smooth muscle cells.

    PubMed

    Andresen, Bradley T; Linnoila, Jenny J; Jackson, Edwin K; Romero, Guillermo G

    2003-03-01

    Angiotensin (Ang) II promotes the phosphorylation of extracellular regulated kinase (ERK); however, the mechanisms leading to Ang II-induced ERK phosphorylation are debated. The currently accepted theory involves transactivation of epidermal growth factor receptor (EGFR). We have shown that generation of phosphatidic acid (PA) is required for the recruitment of Raf to membranes and the activation of ERK by multiple agonists, including Ang II. In the present report, we confirm that phospholipase D-dependent generation of PA is required for Ang II-mediated phosphorylation of ERK in Wistar-Kyoto and spontaneously hypertensive rat preglomerular smooth muscle cells (PGSMCs). However, EGF stimulation does not activate phospholipase D or generate PA. These observations indicate that EGF recruits Raf to membranes via a mechanism that does not involve PA, and thus, Ang II-mediated phosphorylation of ERK is partially independent of EGFR-mediated signaling cascades. We hypothesized that phosphoinositide-3-kinase (PI3K) can also act to recruit Raf to membranes; therefore, inhibition of PI3K should inhibit EGF signaling to ERK. Wortmannin, a PI3K inhibitor, inhibited EGF-mediated phosphorylation of ERK (IC50, approximately 14 nmol/L). To examine the role of the EGFR in Ang II-mediated phosphorylation of ERK we utilized 100 nmol/L wortmannin to inhibit EGFR signaling to ERK and T19N RhoA to block Ang II-mediated ERK phosphorylation. Wortmannin treatment inhibited EGF-mediated but not Ang II-mediated phosphorylation of ERK. Furthermore, T19N RhoA inhibited Ang II-mediated ERK phosphorylation, whereas T19N RhoA had significantly less effect on EGF-mediated ERK phosphorylation. We conclude that transactivation of the EGFR is not primarily responsible for Ang II-mediated activation of ERK in PGSMCs.

  12. Nesprin-2-dependent ERK1/2 compartmentalisation regulates the DNA damage response in vascular smooth muscle cell ageing

    PubMed Central

    Warren, D T; Tajsic, T; Porter, L J; Minaisah, R M; Cobb, A; Jacob, A; Rajgor, D; Zhang, Q P; Shanahan, C M

    2015-01-01

    Prelamin A accumulation and persistent DNA damage response (DDR) are hallmarks of vascular smooth muscle cell (VSMC) ageing and dysfunction. Although prelamin A is proposed to interfere with DNA repair, our understanding of the crosstalk between prelamin A and the repair process remains limited. The extracellular signal-regulated kinases 1 and 2 (ERK1/2) have emerged as key players in the DDR and are known to enhance ataxia telangiectasia-mutated protein (ATM) activity at DNA lesions, and in this study, we identified a novel relationship between prelamin A accumulation and ERK1/2 nuclear compartmentalisation during VSMC ageing. We show both prelamin A accumulation and increased DNA damage occur concomitantly, before VSMC replicative senescence, and induce the localisation of ERK1/2 to promyelocytic leukaemia protein nuclear bodies (PML NBs) at the sites of DNA damage via nesprin-2 and lamin A interactions. Importantly, VSMCs treated with DNA damaging agents also displayed prelamin A accumulation and ERK compartmentalisation at PML NBs, suggesting that prelamin A and nesprin-2 are novel components of the DDR. In support of this, disruption of ERK compartmentalisation at PML NBs, by either depletion of nesprin-2 or lamins A/C, resulted in the loss of ATM from DNA lesions. However, ATM signalling and DNA repair remained intact after lamins A/C depletion, whereas nesprin-2 disruption ablated downstream Chk2 activation and induced genomic instability. We conclude that lamins A/C and PML act as scaffolds to organise DNA-repair foci and compartmentalise nesprin-2/ERK signalling. However, nesprin-2/ERK signalling fidelity, but not their compartmentalisation at PML NBs, is essential for efficient DDR in VSMCs. PMID:25744025

  13. Toll like receptor-2 regulates production of glial-derived neurotrophic factors in murine intestinal smooth muscle cells.

    PubMed

    Brun, Paola; Gobbo, Serena; Caputi, Valentina; Spagnol, Lisa; Schirato, Giulia; Pasqualin, Matteo; Levorato, Elia; Palù, Giorgio; Giron, Maria Cecilia; Castagliuolo, Ignazio

    2015-09-01

    Gut microbiota-innate immunity axis is emerging as a key player to guarantee the structural and functional integrity of the enteric nervous system (ENS). Alterations in the composition of the gut microbiota, derangement in signaling of innate immune receptors such as Toll-like receptors (TLRs), and modifications in the neurochemical coding of the ENS have been associated with a variety of gastrointestinal disorders. Indeed, TLR2 activation by microbial products controls the ENS structure and regulates intestinal neuromuscular function. However, the cellular populations and the molecular mechanisms shaping the plasticity of enteric neurons in response to gut microbes are largely unexplored. In this study, smooth muscle cells (SMCs), enteric glial cells (EGCs) and macrophages/dendritic cells (MΦ/DCs) were isolated and cultured from the ileal longitudinal muscle layer of wild-type (WT) and Toll-like receptor-2 deficient (TLR2(-/-)) mice. Quantification of mRNA levels of neurotrophins at baseline and following stimulation with TLR ligands was performed by RT-PCR. To determine the role of neurotrophins in supporting the neuronal phenotype, we performed co-culture experiments of enteric neurons with the conditioned media of cells isolated from the longitudinal muscle layer of WT or TLR2(-/-) mice. The neuronal phenotype was investigated evaluating the expression of βIII-tubulin, HuC/D, and nNOS by immunocytochemistry. As detected by semi-quantitative RT-PCR, SMCs expressed mRNA coding TLR1-9. Among the tested cell populations, un-stimulated SMCs were the most prominent sources of neurotrophins. Stimulation with TLR2, TLR4, TLR5 and TLR9 ligands further increased Gdnf, Ngf, Bdnf and Lif mRNA levels in SMCs. Enteric neurons isolated from TLR2(-/-) mice exhibited smaller ganglia, fewer HuC/D(+ve) and nNOS(+ve) neurons and shorter βIII-tubulin axonal networks as compared to neurons cultured from WT mice. The co-culture with the conditioned media from WT-SMCs but not with

  14. Coronary Artery Disease Associated Transcription Factor TCF21 Regulates Smooth Muscle Precursor Cells That Contribute to the Fibrous Cap

    PubMed Central

    Raiesdana, Azad; Kundu, Ramendra; Miller, Clint L.; Kim, Juyong B.; Arora, Komal; Carcamo-Oribe, Ivan; Xiong, Yiqin; Tellakula, Nikhil; Nanda, Vivek; Murthy, Nikitha; Boisvert, William A.; Hedin, Ulf; Perisic, Ljubica; Aldi, Silvia; Maegdefessel, Lars; Pjanic, Milos; Owens, Gary K.; Tallquist, Michelle D.; Quertermous, Thomas

    2015-01-01

    Recent genome wide association studies have identified a number of genes that contribute to the risk for coronary heart disease. One such gene, TCF21, encodes a basic-helix-loop-helix transcription factor believed to serve a critical role in the development of epicardial progenitor cells that give rise to coronary artery smooth muscle cells (SMC) and cardiac fibroblasts. Using reporter gene and immunolocalization studies with mouse and human tissues we have found that vascular TCF21 expression in the adult is restricted primarily to adventitial cells associated with coronary arteries and also medial SMC in the proximal aorta of mouse. Genome wide RNA-Seq studies in human coronary artery SMC (HCASMC) with siRNA knockdown found a number of putative TCF21 downstream pathways identified by enrichment of terms related to CAD, including “vascular disease,” “disorder of artery,” and “occlusion of artery,” as well as disease-related cellular functions including “cellular movement” and “cellular growth and proliferation.” In vitro studies in HCASMC demonstrated that TCF21 expression promotes proliferation and migration and inhibits SMC lineage marker expression. Detailed in situ expression studies with reporter gene and lineage tracing revealed that vascular wall cells expressing Tcf21 before disease initiation migrate into vascular lesions of ApoE-/- and Ldlr-/- mice. While Tcf21 lineage traced cells are distributed throughout the early lesions, in mature lesions they contribute to the formation of a subcapsular layer of cells, and others become associated with the fibrous cap. The lineage traced fibrous cap cells activate expression of SMC markers and growth factor receptor genes. Taken together, these data suggest that TCF21 may have a role regulating the differentiation state of SMC precursor cells that migrate into vascular lesions and contribute to the fibrous cap and more broadly, in view of the association of this gene with human CAD, provide

  15. MARCKS Signaling Differentially Regulates Vascular Smooth Muscle and Endothelial Cell Proliferation through a KIS-, p27kip1- Dependent Mechanism

    PubMed Central

    Yu, Dan; Makkar, George; Dong, Tuo; Strickland, Dudley K.; Sarkar, Rajabrata; Monahan, Thomas Stacey

    2015-01-01

    Background Overexpression of the myristolated alanine-rich C kinase substrate (MARCKS) occurs in vascular proliferative diseases such as restenosis after bypass surgery. MARCKS knockdown results in arrest of vascular smooth muscle cell (VSMC) proliferation with little effect on endothelial cell (EC) proliferation. We sought to identify the mechanism of differential regulation by MARCKS of VSMC and EC proliferation in vitro and in vivo. Methods and Results siRNA-mediated MARCKS knockdown in VSMCs inhibited proliferation and prevented progression from phase G0/G1 to S. Protein expression of the cyclin-dependent kinase inhibitor p27kip1, but not p21cip1 was increased by MARCKS knockdown. MARCKS knockdown did not affect proliferation in VSMCs derived from p27kip1-/- mice indicating that the effect of MARCKS is p27kip1-dependent. MARCKS knockdown resulted in decreased phosphorylation of p27kip1 at threonine 187 and serine 10 as well as, kinase interacting with stathmin (KIS), cyclin D1, and Skp2 expression. Phosphorylation of p27kip1 at serine 10 by KIS is required for nuclear export and degradation of p27kip1. MARCKS knockdown caused nuclear trapping of p27kip1. Both p27kip1 nuclear trapping and cell cycle arrest were released by overexpression of KIS, but not catalytically inactive KIS. In ECs, MARCKS knockdown paradoxically increased KIS expression and cell proliferation. MARCKS knockdown in a murine aortic injury model resulted in decreased VSMC proliferation determined by bromodeoxyuridine (BrdU) integration assay, and inhibition of vascular wall thickening. MARCKS knockdown increased the rate of re-endothelialization. Conclusions MARCKS knockdown arrested VSMC cell cycle by decreasing KIS expression. Decreased KIS expression resulted in nuclear trapping of p27kip1 in VSMCs. MARCKS knockdown paradoxically increased KIS expression in ECs resulting in increased EC proliferation. MARCKS knockdown significantly attenuated the VSMC proliferative response to vascular

  16. Differential regulation of phosphoinositide metabolism by alphaVbeta3 and alphaVbeta5 integrins upon smooth muscle cell migration.

    PubMed

    Paulhe, F; Racaud-Sultan, C; Ragab, A; Albiges-Rizo, C; Chap, H; Iberg, N; Morand, O; Perret, B

    2001-11-09

    Smooth muscle cell migration is a key step of atherosclerosis and angiogenesis. We demonstrate that alpha(V)beta(3) and alpha(V)beta(5) integrins synergistically regulate smooth muscle cell migration onto vitronectin. Using an original haptotactic cell migration assay, we measured a strong stimulation of phosphoinositide metabolism in migrating vascular smooth muscle cells. Phosphatidic acid production and phosphoinositide 3-kinase IA activation were triggered only upon alpha(V)beta(3) engagement. Blockade of alpha(V)beta(3) engagement or phospholipase C activity resulted in a strong inhibition of smooth muscle cell spreading on vitronectin. By contrast, blockade of alpha(V)beta(5) reinforced elongation and polarization of cell shape. Moreover, Pyk2-associated tyrosine kinase and phosphoinositide 4-kinase activities measured in Pyk2 immunoprecipitates were stimulated upon cell migration. Blockade of either alpha(V)beta(3) or alpha(V)beta(5) function, as well as inhibition of phospholipase C activity, decreased both Pyk2-associated activities. We demonstrated that the Pyk2-associated phosphoinositide 4-kinase corresponded to the beta isoform. Our data point to the metabolism of phosphoinositides as a regulatory pathway for the differential roles played by alpha(V)beta(3) and alpha(V)beta(5) upon cell migration and identify the Pyk2-associated phosphoinositide 4-kinase beta as a common target for both integrins.

  17. Intravesical treatment of advanced urothelial bladder cancers with oncolytic HSV-1 co-regulated by differentially expressed microRNAs.

    PubMed

    Zhang, K-X; Matsui, Y; Lee, C; Osamu, O; Skinner, L; Wang, J; So, A; Rennie, P S; Jia, W W

    2016-05-01

    Urothelial bladder cancer is the most common malignancy of the urinary tract. Although most cases are initially diagnosed as non-muscle-invasive, more than 80% of patients will develop recurrent or metastatic tumors. No effective therapy exists currently for late-stage metastatic tumors. By intravesical application, local administration of oncolytic Herpes Simplex virus (oHSV-1) can provide a promising new therapy for this disease. However, its inherent neurotoxicity has been a perceived limitation for such application. In this study, we present a novel microRNA-regulatory approach to reduce HSV-1-induced neurotoxicity by suppressing viral replication in neurons while maintaining oncolytic selectivity toward urothelial tumors. Specifically, we designed a recombinant virus that utilizes differentially expressed endogenous microR143 (non-cancerous, ubiquitous) and microR124 (neural-specific) to regulate expression of ICP-4, a gene essential for HSV-1 replication. We found that expression of ICP-4 must be controlled by a combination of both miR143 and miR124 to achieve the most effective attenuation in HSV-1-induced toxicity while retaining maximal oncolytic capacity. These results suggest that interaction between miR143 and miR124 may be required to successfully regulate HSV-1 replication. Our resent study is the first proof-in-principle that miRNA combination can be exploited to fine-tune the replication of HSV-1 to treat human cancers.

  18. Sexual Dimorphism in the Regulation of Estrogen, Progesterone, and Androgen Receptors by Sex Steroids in the Rat Airway Smooth Muscle Cells

    PubMed Central

    Zarazúa, Abraham; González-Arenas, Aliesha; Ramírez-Vélez, Gabriela; Bazán-Perkins, Blanca; Guerra-Araiza, Christian; Campos-Lara, María G.

    2016-01-01

    The role of sex hormones in lung is known. The three main sex steroid receptors, estrogen, progesterone, and androgen, have not been sufficiently studied in airway smooth muscle cells (ASMC), and the sex hormone regulation on these receptors is unknown. We examined the presence and regulation of sex hormone receptors in female and male rat ASMC by Western blotting and flow cytometry. Gonadectomized rats were treated with 17β-estradiol, progesterone, 17β-estradiol + progesterone, or testosterone. ASMC were enzymatically isolated from tracheas and bronchi. The experiments were performed with double staining flow cytometry (anti-α-actin smooth muscle and antibodies to each hormone receptor). ERα, ERβ, tPR, and AR were detected in females or males. ERα was upregulated by E2 and T and downregulated by P4 in females; in males, ERα was downregulated by P4, E + P, and T. ERβ was downregulated by each treatment in females, and only by E + P and T in males. tPR was downregulated by P4, E + P, and T in females. No hormonal regulation was observed in male receptors. AR was downregulated in males treated with E + P and T. We have shown the occurrence of sex hormone receptors in ASMC and their regulation by the sex hormones in female and male rats. PMID:27110242

  19. Sexual Dimorphism in the Regulation of Estrogen, Progesterone, and Androgen Receptors by Sex Steroids in the Rat Airway Smooth Muscle Cells.

    PubMed

    Zarazúa, Abraham; González-Arenas, Aliesha; Ramírez-Vélez, Gabriela; Bazán-Perkins, Blanca; Guerra-Araiza, Christian; Campos-Lara, María G

    2016-01-01

    The role of sex hormones in lung is known. The three main sex steroid receptors, estrogen, progesterone, and androgen, have not been sufficiently studied in airway smooth muscle cells (ASMC), and the sex hormone regulation on these receptors is unknown. We examined the presence and regulation of sex hormone receptors in female and male rat ASMC by Western blotting and flow cytometry. Gonadectomized rats were treated with 17β-estradiol, progesterone, 17β-estradiol + progesterone, or testosterone. ASMC were enzymatically isolated from tracheas and bronchi. The experiments were performed with double staining flow cytometry (anti-α-actin smooth muscle and antibodies to each hormone receptor). ERα, ERβ, tPR, and AR were detected in females or males. ERα was upregulated by E2 and T and downregulated by P4 in females; in males, ERα was downregulated by P4, E + P, and T. ERβ was downregulated by each treatment in females, and only by E + P and T in males. tPR was downregulated by P4, E + P, and T in females. No hormonal regulation was observed in male receptors. AR was downregulated in males treated with E + P and T. We have shown the occurrence of sex hormone receptors in ASMC and their regulation by the sex hormones in female and male rats.

  20. Regulation of intracellular pH in the smooth muscle of guinea-pig ureter: Na+ dependence.

    PubMed Central

    Aickin, C C

    1994-01-01

    1. Mechanisms involved in the regulation of intracellular pH (pHi) in smooth muscle cells of guinea-pig ureter have been investigated using double-barrelled pH-sensitive microelectrodes in isolated strips of tissue. 2. Removal of CO2-HCO3- from the superfusing solution caused a fall in the steady-state pHi except in a few cells which had been excised from the animal for many hours (usually > 24 h). The pHi value was 7.22 +/- 0.09 (n = 89; mean +/- S.D. of an observation) in solution buffered with 5% CO2-21 mM HCO3-, compared with 6.92 +/- 0.24 (n = 67) in the nominal absence of CO2-HCO3-. Recovery from experimentally induced acidosis was faster in the presence, rather than nominal absence, of CO2-HCO3- (mean half-times of 2.7 +/- 0.7 min, n = 41, and 4.6 +/- 1.3 min, n = 12, respectively). These results suggest the presence of both HCO(3-)-dependent and -independent mechanisms for the effective extrusion of acid equivalents. 3. Recovery from acidosis was dependent on external Na+ (Na+o) in both the presence and nominal absence of CO2-HCO3-, with an apparent half-maximal activation at approximately 4 and 20 mM Na+o, respectively. Removal of Na+o in the steady state caused a fall in pHi which proceeded at a faster rate in the presence rather than in the nominal absence of CO2-HCO3-. 4. Amiloride (100 microM-1 mM) reversibly inhibited the recovery from acidosis and caused a fall in the steady-state pHi when applied in the nominal absence of CO2-HCO3-, but had no measurable effect on either the recovery from acidosis or steady-state pHi in the presence of CO2-HCO3-. These results suggest that Na(+)-H+ exchange was responsible for extrusion of acid equivalents in the nominal absence of CO2 and HCO3-, but that it played little part under more physiological conditions. 5. Although Na(+)-H+ exchange appeared to be activated below a pHi of about 7.2, it was incapable of maintaining a 'normal' pHi in the nominal absence of CO2-HCO3- in freshly excised cells, where values

  1. The smooth muscle-selective RhoGAP GRAF3 is a critical regulator of vascular tone and hypertension

    PubMed Central

    Bai, Xue; Lenhart, Kaitlin C.; Bird, Kim E.; Suen, Alisa A.; Rojas, Mauricio; Kakoki, Masao; Li, Feng; Smithies, Oliver; Mack, Christopher P.; Taylor, Joan M.

    2014-01-01

    Although hypertension is a worldwide health issue, an incomplete understanding of its etiology has hindered our ability to treat this complex disease. Here we identify arhgap42 (also known as GRAF3) as a Rho-specific GAP expressed specifically in smooth muscle cells in mice and humans. We show that GRAF3-deficient mice exhibit significant hypertension and increased pressor responses to angiotensin II and endothelin-1; these effects are prevented by treatment with the Rho-kinase inhibitor, Y-27632. RhoA activity and myosin light chain phosphorylation are elevated in GRAF3-depleted smooth muscle cells in vitro and in vivo, and isolated vessel segments from GRAF3-deficient mice show increased contractility. Taken together our data indicate that GRAF3-mediated inhibition of RhoA activity in vascular smooth muscle cells is necessary for maintaining normal blood pressure homeostasis. Moreover, these findings provide a potential mechanism for a hypertensive locus recently identified within arhgap42 and provide a foundation for the future development of innovative hypertension therapies. PMID:24335996

  2. Rare Copy Number Variants Disrupt Genes Regulating Vascular Smooth Muscle Cell Adhesion and Contractility in Sporadic Thoracic Aortic Aneurysms and Dissections

    PubMed Central

    Prakash, Siddharth K.; LeMaire, Scott A.; Guo, Dong-Chuan; Russell, Ludivine; Regalado, Ellen S.; Golabbakhsh, Hossein; Johnson, Ralph J.; Safi, Hazim J.; Estrera, Anthony L.; Coselli, Joseph S.; Bray, Molly S.; Leal, Suzanne M.; Milewicz, Dianna M.; Belmont, John W.

    2010-01-01

    Thoracic aortic aneurysms and dissections (TAAD) cause significant morbidity and mortality, but the genetic origins of TAAD remain largely unknown. In a genome-wide analysis of 418 sporadic TAAD cases, we identified 47 copy number variant (CNV) regions that were enriched in or unique to TAAD patients compared to population controls. Gene ontology, expression profiling, and network analysis showed that genes within TAAD CNVs regulate smooth muscle cell adhesion or contractility and interact with the smooth muscle-specific isoforms of α-actin and β-myosin, which are known to cause familial TAAD when altered. Enrichment of these gene functions in rare CNVs was replicated in independent cohorts with sporadic TAAD (STAAD, n = 387) and inherited TAAD (FTAAD, n = 88). The overall prevalence of rare CNVs (23%) was significantly increased in FTAAD compared with STAAD patients (Fisher's exact test, p = 0.03). Our findings suggest that rare CNVs disrupting smooth muscle adhesion or contraction contribute to both sporadic and familial disease. PMID:21092924

  3. The platelet-derived growth factor receptor/STAT3 signaling pathway regulates the phenotypic transition of corpus cavernosum smooth muscle in rats

    PubMed Central

    Zhao, Jian-Feng; Fu, Hui-Ying; Zhang, Gao-Yue; Huang, Xiao-Jun; Lv, Bo-Dong

    2017-01-01

    Erectile dysfunction (ED) is a common clinical disease that is difficult to treat. We previously found that hypoxia modulates the phenotype of primary corpus cavernosum smooth muscle cells (CCSMCs) in rats, but the underlying molecular mechanism is still unknown. Platelet-derived growth factor receptor (PDGFR)-related signaling pathways are correlated with cell phenotypic transition, but research has been focused more on vascular smooth muscle and tracheal smooth muscle and less on CCSMCs. Here, we investigated the role of PDGFR-related signaling pathways in penile CCSMCs, which were successfully isolated from rats and cultured in vitro. PDGF-BB at 5, 10, or 20 ng/ml altered CCSMC morphology from the original elongated, spindle shape to a broader shape and promoted the synthetic phenotype and expression of the related proteins vimentin and collagen-I, while inhibiting the contractile phenotype and expression of the related proteins smooth muscle (SM) α-actin (α-SMA) and desmin. Inhibition of PDGFR activity via siRNA or the PDGFR inhibitor crenolanib inhibited vimentin and collagen-I expression, increased α-SMA and desmin expression, and considerably inhibited serine-threonine protein kinase (AKT) and signal transducer and activator of transcription 3 (STAT3) phosphorylation. STAT3 knockdown promoted the contractile phenotype, inhibited vimentin and collagen-I expression, and increased α-SMA and desmin expression, whereas AKT knockdown did not affect phenotype-associated proteins. STAT3 overexpression in CCSMC cells weakened the suppressive effect of PDGFR inhibition on the morphology and phenotypic transformation induced by PDGF-BB. Through activation of the PDGFR/STAT3 signaling pathway, PDGF promoted the synthetic phenotype transition; thus, regulation of this pathway might contribute to ED therapy. PMID:28245285

  4. PKC-DEPENDENT REGULATION OF Kv7.5 CHANNELS BY THE BRONCHOCONSTRICTOR HISTAMINE IN HUMAN AIRWAY SMOOTH MUSCLE CELLS.

    PubMed

    Haick, Jennifer M; Brueggemann, Lioubov I; Cribbs, Leanne L; Denning, Mitchell F; Schwartz, Jeffrey; Byron, Kenneth L

    2017-03-10

    Kv7 potassium channels have recently been found to be expressed and functionally important for relaxation of airway smooth muscle. Previous research suggests that native Kv7 currents are inhibited following treatment of freshly isolated airway smooth muscle cells with bronchoconstrictor agonists, and in intact airways inhibition of Kv7 channels is sufficient to induce bronchiolar constriction. However, the mechanism by which Kv7 currents are inhibited by bronchoconstrictor agonists has yet to be elucidated. In the present study, native Kv7 currents in cultured human trachealis smooth muscle cells (HTSMCs) were observed to be inhibited upon treatment with histamine; inhibition of Kv7 currents was associated with membrane depolarization and an increase in cytosolic Ca2+ ([Ca2+]cyt). The latter response was inhibited by verapamil, a blocker of L-type voltage sensitive Ca2+ channels (VSCCs). Protein kinase C (PKC) has been implicated as a mediator of bronchoconstrictor actions, though the targets of PKC are not clearly established. We found that histamine treatment significantly and dose-dependently suppressed currents through overexpressed wild-type human Kv7.5 (hKv7.5) channels in cultured HTSMCs, and this effect was inhibited by the PKC inhibitor Ro-31-8220 (3 µM). The PKC-dependent suppression of hKv7.5 currents corresponded with a PKC-dependent increase in hKv7.5 channel phosphorylation. Knocking down or inhibiting PKCα, or mutating hKv7.5 serine 441 to alanine, abolished the inhibitory effects of histamine on hKv7.5 currents. These findings provide the first evidence linking PKC activation to suppression of Kv7 currents, membrane depolarization, and Ca2+ influx via L-type VSCCs as a mechanism for histamine-induced bronchoconstriction.

  5. INTERMEDIATE FILAMENTS IN SMOOTH MUSCLE

    PubMed Central

    Tang, Dale D.

    2008-01-01

    The intermediate filament (IF) network is one of the three cytoskeletal systems in smooth muscle. The type III IF proteins vimentin and desmin are major constituents of the network in smooth muscle cells and tissues. Lack of vimentin or desmin impairs contractile ability of various smooth muscle preparations, implying their important role for smooth muscle force development. The IF framework has long been viewed as a fixed cytostructure that solely provides mechanical integrity for the cell. However, recent studies suggest that the IF cytoskeleton is dynamic in mammalian cells in response to various external stimulation. In this review, the structure and biological properties of IF proteins in smooth muscle are summarized. The role of IF proteins in the modulation of smooth muscle force development and redistribution/translocation of signaling partners (such as p130 Crk-associated substrate, CAS) is depicted. This review also summarizes our latest understanding on how the IF network may be regulated in smooth muscle. PMID:18256275

  6. TRPA1-dependent regulation of bladder detrusor smooth muscle contractility in normal and type I diabetic rats

    PubMed Central

    Philyppov, Igor B.; Paduraru, Oksana N.; Gulak, Kseniya L.; Skryma, Roman; Prevarskaya, Natalia; Shuba, Yaroslav M.

    2016-01-01

    TRPA1 is a Ca2+-permeable cation channel that is activated by painful low temperatures (˂17 °C), irritating chemicals, reactive metabolites and mediators of inflammation. In the bladder TRPA1 is predominantly expressed in sensory afferent nerve endings, where it mediates sensory transduction. The contractile effect of its activation on detrusor smooth muscle (DSM) is explained by the release from sensory afferents of inflammatory factors – tachykinins and prostaglandins, which cause smooth muscle cell contraction. Diabetes is a systemic disease, with common complications being diabetic cystopathies and urinary incontinence. However, data on how diabetes affects bladder contractility associated with TRPA1 activation are not available. In this study, by using a rat model with streptozotocin-induced type I diabetes, contractility measurements of DSM strips in response to TRPA1-activating and modulating pharmacological agents and assessment of TRPA1 mRNA expression in bladder-innervating dorsal root ganglia, we have shown that diabetes enhances the TRPA1-dependent mechanism involved in bladder DSM contractility. This is not due to changes in TRPA1 expression, but mainly due to the general inflammatory reaction caused by diabetes. The latter leads to an increase in cyclooxygenase-2-dependent prostaglandin synthesis through the mechanisms associated with substance P activity. This results in the enhanced functional coupling between the tachykinin and prostanoid systems, and the concomitant increase of their impact on DSM contractility in response to TRPA1 activation. PMID:26935999

  7. A nonparametric mean-variance smoothing method to assess Arabidopsis cold stress transcriptional regulator CBF2 overexpression microarray data.

    PubMed

    Hu, Pingsha; Maiti, Tapabrata

    2011-01-01

    Microarray is a powerful tool for genome-wide gene expression analysis. In microarray expression data, often mean and variance have certain relationships. We present a non-parametric mean-variance smoothing method (NPMVS) to analyze differentially expressed genes. In this method, a nonlinear smoothing curve is fitted to estimate the relationship between mean and variance. Inference is then made upon shrinkage estimation of posterior means assuming variances are known. Different methods have been applied to simulated datasets, in which a variety of mean and variance relationships were imposed. The simulation study showed that NPMVS outperformed the other two popular shrinkage estimation methods in some mean-variance relationships; and NPMVS was competitive with the two methods in other relationships. A real biological dataset, in which a cold stress transcription factor gene, CBF2, was overexpressed, has also been analyzed with the three methods. Gene ontology and cis-element analysis showed that NPMVS identified more cold and stress responsive genes than the other two methods did. The good performance of NPMVS is mainly due to its shrinkage estimation for both means and variances. In addition, NPMVS exploits a non-parametric regression between mean and variance, instead of assuming a specific parametric relationship between mean and variance. The source code written in R is available from the authors on request.

  8. TRPA1-dependent regulation of bladder detrusor smooth muscle contractility in normal and type I diabetic rats.

    PubMed

    Philyppov, Igor B; Paduraru, Oksana N; Gulak, Kseniya L; Skryma, Roman; Prevarskaya, Natalia; Shuba, Yaroslav M

    2016-01-01

    TRPA1 is a Ca(2+)-permeable cation channel that is activated by painful low temperatures (<17°C), irritating chemicals, reactive metabolites and mediators of inflammation. In the bladder TRPA1 is predominantly expressed in sensory afferent nerve endings, where it mediates sensory transduction. The contractile effect of its activation on detrusor smooth muscle (DSM) is explained by the release from sensory afferents of inflammatory factors - tachykinins and prostaglandins, which cause smooth muscle cell contraction. Diabetes is a systemic disease, with common complications being diabetic cystopathies and urinary incontinence. However, data on how diabetes affects bladder contractility associated with TRPA1 activation are not available. In this study, by using a rat model with streptozotocin-induced type I diabetes, contractility measurements of DSM strips in response to TRPA1-activating and modulating pharmacological agents and assessment of TRPA1 mRNA expression in bladder-innervating dorsal root ganglia, we have shown that diabetes enhances the TRPA1-dependent mechanism involved in bladder DSM contractility. This is not due to changes in TRPA1 expression, but mainly due to the general inflammatory reaction caused by diabetes. The latter leads to an increase in cyclooxygenase-2-dependent prostaglandin synthesis through the mechanisms associated with substance P activity. This results in the enhanced functional coupling between the tachykinin and prostanoid systems, and the concomitant increase of their impact on DSM contractility in response to TRPA1 activation.

  9. [THE ROLE OF HYDROGEN SULFIDE IN VOLUME-DEPENDENT MECHANISMS OF REGULATION OF VASCULAR SMOOTH MUSCLE CELLS CONTRACTILE ACTIVITY].

    PubMed

    Smagliy, L V; Gusakova, S V; Birulina, Yu G; Kovalev, I V; Orlov, S N

    2015-04-01

    The hydrogen sulfide (H2S) influence on the contractile activity of vascular smooth muscle cells (SMC) was studied on endothelium-denuded aortic ring segments of male Wistar rats with method of mechanography. Contractions of SMS were induced by incubation in high potassium solution as well as in hyper-, hypo- and isosmotic solutions. 5-100 LM of H2S donor--sodium hydrosulfide (NaHS) increased mechanical tension of SMC precontracted with high potassium solution that was abolished by bumetanide--the inhibitor of Na+, K+, 2Cl(-) -cotransporter (NKCC), but 100-1000 microM of NaHS relaxed SMS. NaHS (10 microM) increased the amplitude of hyper- and isosmotic contraction, but not of hyposmotic contraction. NaHS (ImM) decreased the amplitude of hyper-, iso-, and hyposmotic contractions. The direct measurements of NKCC activity with radionuclide method showed an increase in NKCC activity under the action of 5-100 microM of NaHS. These findings suggest that low concentrations of H2S participate in the NKCC activation. This mechanism underlines constrictive action of H2S on smooth muscle cells.

  10. AB283. SPR-10 Down-regulation of ryanodine receptor gene expression in murine urinary bladder smooth muscle following partial bladder outlet obstruction

    PubMed Central

    Boopathi, Ettickan; Javed, Elham; Addya, Shankar; Fortina, Paolo; Zderic, Stephen; Wein, Alan; Chacko, Samuel

    2016-01-01

    Objective Urinary bladder smooth muscle (UBSM) displays spontaneous action potentials and this potential is related to the phasic nature of spontaneous contractions in this tissue. The amplitude of a phasic contraction depends on the increase in Ca2+ entry caused by membrane depolarization. Ryanodine receptors (RyRs) in UBSM decreases the force production by decreasing the frequency of phasic contractions through interactions with large-conductance Ca2+-activated K+ (BK) and small-conductance Ca2+-activated K+ (SK) channels. Microarray and network analysis were employed to determine the changes in mRNA in 14-day obstructed murine bladders. We found that obstruction significantly down-regulated the RyRs in bladder smooth muscle (BSM). Methods Male C57Bl/6 mice were surgically obstructed and kept for 14 days. Sham-operated mice served as a control. Bladders were excised; urothelium scraped off with a scalpel, and the serosa was removed. BSM obtained from PBOO and sham control animals were used for microarray and western blotting Results Pathway-based analysis of these gene signatures showed significant number of under-expressed genes in obstructed bladder and they were mapped to proteins involved in calcium signaling. We focused our work on RyR protein expression in BSM. There was a four-fold reduction of RyR3 in BSM in 14-day obstructed groups as shown by microarray and immunoblotting compared to that of sham-operated animals. Conclusions These results confirm that the RyR gene expression is down-regulated in obstructed murine bladder smooth muscle. Funding Source(s) None

  11. Smooth Sailing.

    ERIC Educational Resources Information Center

    Price, Beverley; Pincott, Maxine; Rebman, Ashley; Northcutt, Jen; Barsanti, Amy; Silkunas, Betty; Brighton, Susan K.; Reitz, David; Winkler, Maureen

    1999-01-01

    Presents discipline tips from several teachers to keep classrooms running smoothly all year. Some of the suggestions include the following: a bear-cave warning system, peer mediation, a motivational mystery, problem students acting as the teacher's assistant, a positive-behavior-reward chain, a hallway scavenger hunt (to ensure quiet passage…

  12. Sphingolipids regulate [Mg2+]o uptake and [Mg2+]i content in vascular smooth muscle cells: potential mechanisms and importance to membrane transport of Mg2+.

    PubMed

    Zheng, Tao; Li, Wenyan; Altura, Bella T; Shah, Nilank C; Altura, Burton M

    2011-02-01

    Sphingolipids have a variety of important signaling roles in mammalian cells. We tested the hypothesis that certain sphingolipids and neutral sphingomyelinase (N-SMase) can regulate intracellular free magnesium ions ([Mg2+]i) in vascular smooth muscle (VSM) cells. Herein, we show that several sphingolipids, including C2-ceramide, C8-ceramide, C16-ceramide, and sphingosine, as well as N-SMase, have potent and direct effects on content and mobilization of [Mg2+]i in primary cultured rat aortic smooth muscle cells. All of these sphingolipid molecules increase, rapidly, [Mg2+]i in these vascular cells in a concentration-dependent manner. The increments of [Mg2+]i, induced by these agents, are derived from influx of extracellular Mg2+ and are extracellular Ca2+ concentration-dependent. Phospholipase C and Ca2+/calmodulin/Ca2+-ATPase activity appear to be important in the sphingolipid-induced rises of [Mg2+]i. Activation of certain PKC isozymes may also be required for sphingolipid-induced rises in [Mg2+]i. These novel results suggest that sphingolipids may be homeostatic regulators of extracellular Mg2+ concentration influx (and transport) and [Mg2+]i content in vascular muscle cells.

  13. Tape-Smoothing Tool For Adhesion Tests

    NASA Technical Reports Server (NTRS)

    Allen, Peter B.

    1992-01-01

    Small tool smoothes adhesive tape uniformly to ensure consistency and repeatability of tape-peel tests of adhesion of paint to substrate. Includes resilient pad covered with tough, smooth fabric. Internal spring regulates force applied to tape.

  14. Cross-talk between p(38)MAPK and G iα in regulating cPLA 2 activity by ET-1 in pulmonary smooth muscle cells.

    PubMed

    Chakraborti, Sajal; Chowdhury, Animesh; Chakraborti, Tapati

    2015-02-01

    Endothelin-1 (ET-1) is known as the most potent vasoconstrictor yet described. Infusion of ET-1 into isolated rabbit lung has been shown to cause pulmonary vasoconstriction with the involvement of arachidonic acid metabolites. Given the potency of arachidonic acid metabolites, the activity of phospholipase A2 must be tightly regulated. Herein, we determined the mechanisms by which ET-1 stimulates cPLA2 activity during ET-1 stimulation of bovine pulmonary artery smooth muscle cells. We demonstrated that (i) treatment of bovine pulmonary artery smooth muscle cells with ET-1 stimulates cPLA2 activity in the cell membrane; (ii) ET-1 caused increase in O 2 (·-) production occurs via NADPH oxidase-dependent mechanism; (iii) ET-1-stimulated NADPH oxidase activity is markedly prevented upon pretreatment with PKC-ζ inhibitor, indicating that PKC-ζ plays a prominent role in this scenario; (iv) ET-1-induced NADPH oxidase-derived O 2 (·-) stimulates an aprotinin sensitive protease activity due to prominent increase in [Ca(2+)]i; (v) the aprotinin sensitive protease plays a pivotal role in activating PKC-α, which in turn phosphorylates p(38)MAPK and subsequently Giα leading to the activation of cPLA2. Taken together, we suggest that cross-talk between p(38)MAPK and Giα with the involvement of PKC-ζ, NADPH oxidase-derived O 2 (·-) , [Ca(2+)]i, aprotinin-sensitive protease and PKC-α play a pivotal role for full activation of cPLA2 during ET-1 stimulation of pulmonary artery smooth muscle cells.

  15. Transforming growth factor β-activated kinase 1 negatively regulates interleukin-1α-induced stromal-derived factor-1 expression in vascular smooth muscle cells

    SciTech Connect

    Yang, Bin; Li, Wei; Zheng, Qichang; Qin, Tao; Wang, Kun; Li, Jinjin; Guo, Bing; Yu, Qihong; Wu, Yuzhe; Gao, Yang; Cheng, Xiang; Hu, Shaobo; Kumar, Stanley Naveen; Liu, Sanguang; Song, Zifang

    2015-07-17

    Stromal-derived Factor-1 (SDF-1) derived from vascular smooth muscle cells (VSMCs) contributes to vascular repair and remodeling in various vascular diseases. In this study, the mechanism underlying regulation of SDF-1 expression by interleukin-1α (IL-1α) was investigated in primary rat VSMCs. We found IL-1α promotes SDF-1 expression by up-regulating CCAAT-enhancer-binding protein β (C/EBPβ) in an IκB kinase β (IKKβ) signaling-dependent manner. Moreover, IL-1α-induced expression of C/EBPβ and SDF-1 was significantly potentiated by knockdown of transforming growth factor β-activated kinase 1 (TAK1), an upstream activator of IKKβ signaling. In addition, we also demonstrated that TAK1/p38 mitogen-activated protein kinase (p38 MAPK) signaling exerted negative effect on IL-1α-induced expression of C/EBPβ and SDF-1 through counteracting ROS-dependent up-regulation of nuclear factor erythroid 2-related factor 2 (NRF2). In conclusion, TAK1 acts as an important regulator of IL-1α-induced SDF-1 expression in VSMCs, and modulating activity of TAK1 may serve as a potential strategy for modulating vascular repair and remodeling. - Highlights: • IL-1α induces IKKβ signaling-dependent SDF-1 expression by up-regulating C/EBPβ. • Activation of TAK1 by IL-1α negatively regulates C/EBPβ-dependent SDF-1 expression. • IL-1α-induced TAK1/p38 MAPK signaling counteracts ROS-dependent SDF-1 expression. • TAK1 counteracts IL-1α-induced SDF-1 expression by attenuating NRF2 up-regulation.

  16. Ubiquitin carboxyl terminal hydrolase L1 negatively regulates TNF{alpha}-mediated vascular smooth muscle cell proliferation via suppressing ERK activation

    SciTech Connect

    Ichikawa, Tomonaga; Li, Jinqing; Dong, Xiaoyu; Potts, Jay D.; Tang, Dong-Qi; Li, Dong-Sheng; Cui, Taixing

    2010-01-01

    Deubiquitinating enzymes (DUBs) appear to be critical regulators of a multitude of processes such as proliferation, apoptosis, differentiation, and inflammation. We have recently demonstrated that a DUB of ubiquitin carboxyl terminal hydrolase L1 (UCH-L1) inhibits vascular lesion formation via suppressing inflammatory responses in vasculature. However, the precise underlying mechanism remains to be defined. Herein, we report that a posttranscriptional up-regulation of UCH-L1 provides a negative feedback to tumor necrosis factor alpha (TNF{alpha})-mediated activation of extracellular signal-regulated kinases (ERK) and proliferation in vascular smooth muscle cells (VSMCs). In rat adult VSMCs, adenoviral over-expression of UCH-L1 inhibited TNF{alpha}-induced activation of ERK and DNA synthesis. In contrast, over-expression of UCH-L1 did not affect platelet derived growth factor (PDGF)-induced VSMC proliferation and activation of growth stimulating cascades including ERK. TNF{alpha} hardly altered UCH-L1 mRNA expression and stability; however, up-regulated UCH-L1 protein expression via increasing UCH-L1 translation. These results uncover a novel mechanism by which UCH-L1 suppresses vascular inflammation.

  17. Mechanisms controlling the smooth muscle cell death in progeria via down-regulation of poly(ADP-ribose) polymerase 1.

    PubMed

    Zhang, Haoyue; Xiong, Zheng-Mei; Cao, Kan

    2014-06-03

    Hutchinson-Gilford progeria syndrome (HGPS) is a severe human premature aging disorder caused by a lamin A mutant named progerin. Death occurs at a mean age of 13 y from cardiovascular problems. Previous studies revealed loss of vascular smooth muscle cells (SMCs) in the media of large arteries in a patient with HGPS and two mouse models, suggesting a causal connection between the SMC loss and cardiovascular malfunction. However, the mechanisms of how progerin leads to massive SMC loss are unknown. In this study, using SMCs differentiated from HGPS induced pluripotent stem cells, we show that HGPS SMCs exhibit a profound proliferative defect, which is primarily caused by caspase-independent cell death. Importantly, progerin accumulation stimulates a powerful suppression of PARP1 and consequently triggers an activation of the error-prone nonhomologous end joining response. As a result, most HGPS SMCs exhibit prolonged mitosis and die of mitotic catastrophe. This study demonstrates a critical role of PARP1 in mediating SMC loss in patients with HGPS and elucidates a molecular pathway underlying the progressive SMC loss in progeria.

  18. Hypoxia stimulates the autocrine regulation of migration of vascular smooth muscle cells via HIF-1alpha-dependent expression of thrombospondin-1.

    PubMed

    Osada-Oka, Mayuko; Ikeda, Takako; Akiba, Satoshi; Sato, Takashi

    2008-08-01

    The migration of vascular smooth muscle cells from the media to intima and their subsequent proliferation are critical causes of arterial wall thickening. In atherosclerotic lesions increases in the thickness of the vascular wall and the impairment of oxygen diffusion capacity result in the development of hypoxic lesions. We investigated the effect of hypoxia on the migration of human coronary artery smooth muscle cells (CASMCs) via HIF-1alpha-dependent expression of thrombospondin-1 (TSP-1). When the cells were cultured under hypoxic conditions, mRNA and protein levels of TSP-1, and mRNA levels of integrin beta(3) were increased with the increase in HIF-1alpha protein. DNA synthesis and migration of the cells were stimulated under the conditions, and a neutralizing anti-TSP-1 antibody apparently suppressed the migration, but not DNA synthesis. The migration was also inhibited by RGD peptide that binds to integrin beta(3). Furthermore, the migration was completely suppressed in HIF-1alpha-knockdown cells exposed to hypoxia, while it was significantly enhanced in HIF-1alpha-overexpressing cells. These results suggest that the hypoxia induces the migration of CASMCs, and that the migration is elicited by TSP-1 of which induction is fully dependent on the stabilization of HIF-1alpha, in autocrine regulation. Thus we suggest that HIF-1alpha plays an important role in the pathogenesis of atherosclerosis.

  19. A conserved MADS-box phosphorylation motif regulates differentiation and mitochondrial function in skeletal, cardiac, and smooth muscle cells.

    PubMed

    Mughal, W; Nguyen, L; Pustylnik, S; da Silva Rosa, S C; Piotrowski, S; Chapman, D; Du, M; Alli, N S; Grigull, J; Halayko, A J; Aliani, M; Topham, M K; Epand, R M; Hatch, G M; Pereira, T J; Kereliuk, S; McDermott, J C; Rampitsch, C; Dolinsky, V W; Gordon, J W

    2015-10-29

    Exposure to metabolic disease during fetal development alters cellular differentiation and perturbs metabolic homeostasis, but the underlying molecular regulators of this phenomenon in muscle cells are not completely understood. To address this, we undertook a computational approach to identify cooperating partners of the myocyte enhancer factor-2 (MEF2) family of transcription factors, known regulators of muscle differentiation and metabolic function. We demonstrate that MEF2 and the serum response factor (SRF) collaboratively regulate the expression of numerous muscle-specific genes, including microRNA-133a (miR-133a). Using tandem mass spectrometry techniques, we identify a conserved phosphorylation motif within the MEF2 and SRF Mcm1 Agamous Deficiens SRF (MADS)-box that regulates miR-133a expression and mitochondrial function in response to a lipotoxic signal. Furthermore, reconstitution of MEF2 function by expression of a neutralizing mutation in this identified phosphorylation motif restores miR-133a expression and mitochondrial membrane potential during lipotoxicity. Mechanistically, we demonstrate that miR-133a regulates mitochondrial function through translational inhibition of a mitophagy and cell death modulating protein, called Nix. Finally, we show that rodents exposed to gestational diabetes during fetal development display muscle diacylglycerol accumulation, concurrent with insulin resistance, reduced miR-133a, and elevated Nix expression, as young adult rats. Given the diverse roles of miR-133a and Nix in regulating mitochondrial function, and proliferation in certain cancers, dysregulation of this genetic pathway may have broad implications involving insulin resistance, cardiovascular disease, and cancer biology.

  20. Role of cAMP-Phosphodiesterase 1C Signaling in Regulating Growth Factor Receptor Stability, Vascular Smooth Muscle Cell Growth, Migration, and Neointimal Hyperplasia

    PubMed Central

    Cai, Yujun; Nagel, David J.; Zhou, Qian; Cygnar, Katherine D.; Zhao, Haiqing; Li, Faqian; Pi, Xinchun; Knight, Peter A.; Yan, Chen

    2015-01-01

    Objective Neointimal hyperplasia characterized by abnormal accumulation of vascular smooth muscle cells (SMCs) is a hallmark of occlusive disorders such as atherosclerosis, post-angioplasty restenosis, vein graft stenosis, and allograft vasculopathy. Cyclic nucleotides are vital in SMC proliferation and migration, which are regulated by cyclic nucleotide phosphodiesterases (PDEs). Our goal is to understand the regulation and function of PDEs in SMC pathogenesis of vascular diseases. Methods & Results We performed screening for genes differentially expressed in normal contractile versus proliferating synthetic SMCs. We observed that PDE1C expression was low in contractile SMCs but drastically elevated in synthetic SMCs in vitro and in various mouse vascular injury models in vivo. Additionally, PDE1C was highly induced in neointimal SMCs of human coronary arteries. More importantly, injury-induced neointimal formation was significantly attenuated by PDE1C deficiency or PDE1 inhibition in vivo. PDE1 inhibition suppressed vascular remodeling of human saphenous vein explants ex vivo. In cultured SMCs, PDE1C deficiency or PDE1 inhibition attenuated SMC proliferation and migration. Mechanistic studies revealed that PDE1C plays a critical role in regulating the stability of growth factor receptors, such as PDGF-receptor-beta (PDGFRβ) known to be important in pathological vascular remodeling. PDE1C interacts with LDL-receptor-related-protein-1 (LRP1) and PDGFRβ, thus regulating PDGFRβ endocytosis and lysosome-dependent degradation in an LRP1-dependent manner. A transmembrane-adenylyl-cyclase (tmAC)-cAMP-PKA cascade modulated by PDE1C is critical in regulating PDGFRβ degradation. Conclusion These findings demonstrated that PDE1C is an important regulator of SMC proliferation, migration, and neointimal hyperplasia, in part through modulating endosome/lysosome dependent PDGFRβ protein degradation via LRP1. PMID:25608528

  1. BMP-9 regulates the osteoblastic differentiation and calcification of vascular smooth muscle cells through an ALK1 mediated pathway

    PubMed Central

    Zhu, Dongxing; Mackenzie, Neil Charles Wallace; Shanahan, Catherine M; Shroff, Rukshana C; Farquharson, Colin; MacRae, Vicky Elizabeth

    2015-01-01

    The process of vascular calcification shares many similarities with that of physiological skeletal mineralization, and involves the deposition of hydroxyapatite crystals in arteries. However, the cellular mechanisms responsible have yet to be fully explained. Bone morphogenetic protein (BMP-9) has been shown to exert direct effects on both bone development and vascular function. In the present study, we have investigated the role of BMP-9 in vascular smooth muscle cell (VSMC) calcification. Vessel calcification in chronic kidney disease (CKD) begins pre-dialysis, with factors specific to the dialysis milieu triggering accelerated calcification. Intriguingly, BMP-9 was markedly elevated in serum from CKD children on dialysis. Furthermore, in vitro studies revealed that BMP-9 treatment causes a significant increase in VSMC calcium content, alkaline phosphatase (ALP) activity and mRNA expression of osteogenic markers. BMP-9-induced calcium deposition was significantly reduced following treatment with the ALP inhibitor 2,5-Dimethoxy-N-(quinolin-3-yl) benzenesulfonamide confirming the mediatory role of ALP in this process. The inhibition of ALK1 signalling using a soluble chimeric protein significantly reduced calcium deposition and ALP activity, confirming that BMP-9 is a physiological ALK1 ligand. Signal transduction studies revealed that BMP-9 induced Smad2, Smad3 and Smad1/5/8 phosphorylation. As these Smad proteins directly bind to Smad4 to activate target genes, siRNA studies were subsequently undertaken to examine the functional role of Smad4 in VSMC calcification. Smad4-siRNA transfection induced a significant reduction in ALP activity and calcium deposition. These novel data demonstrate that BMP-9 induces VSMC osteogenic differentiation and calcification via ALK1, Smad and ALP dependent mechanisms. This may identify new potential therapeutic strategies for clinical intervention. PMID:25297851

  2. Regulation of Heparan Sulfate and Chondroitin Sulfate Glycosaminoglycan Biosynthesis by 4-Fluoro-glucosamine in Murine Airway Smooth Muscle Cells*

    PubMed Central

    Nigro, Julie; Wang, Aimin; Mukhopadhyay, Durba; Lauer, Mark; Midura, Ronald J.; Sackstein, Robert; Hascall, Vincent C.

    2009-01-01

    The importance of the pathological changes in proteoglycans has driven the need to study and design novel chemical tools to control proteoglycan synthesis. Accordingly, we tested the fluorinated analogue of glucosamine (4-fluoro-N-acetyl-glucosamine (4-F-GlcNAc)) on the synthesis of heparan sulfate (HS) and chondroitin sulfate (CS) by murine airway smooth muscle (ASM) cells in the presence of radiolabeled metabolic precursors. Secreted and cell-associated CS and HS were assessed for changes in size by Superose 6 chromatography. Treatment of ASM cells with 4-F-GlcNAc (100 μm) reduced the quantity (by 64.1–76.6%) and decreased the size of HS/CS glycosaminoglycans associated with the cell layer (Kav shifted from 0.30 to 0.45). The quantity of CS secreted into the medium decreased by 65.7–73.0%, and the size showed a Kav shift from 0.30 to 0.50. Treatment of ASM cells with 45 μm and 179 μm 4-F-GlcNAc in the presence of a stimulator of CS synthesis, 4-methylumbelliferyl-β-d-xyloside, reduced the amount of the xyloside-CS chains by 65.4 and 87.0%, respectively. The size of xyloside-CS chains synthesized in the presence of 4-F-GlcNAc were only slightly larger than those with xyloside treatment alone (Kav of 0.55 compared with that of 0.6). The effects of 4-F-GlcNAc to inhibit CS synthesis were not observed with equimolar concentrations of glucosamine. We propose that 4-F-GlcNAc inhibits CS synthesis by inhibiting 4-epimerization of UDP-GlcNAc to UDP-GalNAc, thereby depleting one of the substrates required, whereas HS elongation is inhibited by truncation when the nonreducing terminus of the growing chain is capped with 4-F-GlcNAc. PMID:19346253

  3. BET Bromodomains Regulate Transforming Growth Factor-β-induced Proliferation and Cytokine Release in Asthmatic Airway Smooth Muscle*

    PubMed Central

    Perry, Mark M.; Durham, Andrew L.; Austin, Philip J.; Adcock, Ian M.; Chung, Kian Fan

    2015-01-01

    Airway smooth muscle (ASM) mass is increased in asthma, and ASM cells from patients with asthma are hyperproliferative and release more IL-6 and CXCL8. The BET (bromo- and extra-terminal) family of proteins (Brd2, Brd3, and Brd4) govern the assembly of histone acetylation-dependent chromatin complexes. We have examined whether they modulate proliferation and cytokine expression in asthmatic ASM cells by studying the effect of BET bromodomain mimics JQ1/SGCBD01 and I-BET762. ASM cells from healthy individuals and nonsevere and severe asthmatics were pretreated with JQ1/SGCBD01 and I-BET762 prior to stimulation with FCS and TGF-β. Proliferation was measured by BrdU incorporation. IL-6 and CXCL8 release was measured by ELISA, and mRNA expression was measured by quantitative RT-PCR. ChIP using a specific anti-Brd4 antibody and PCR primers directed against the transcriptional start site of IL-6 and CXCL8 gene promoters was performed. Neither JQ1/SGCBD01 nor I-BET762 had any effect on ASM cell viability. JQ1/SGCBD01 and I-BET762 inhibited FCS+TGF-β-induced ASM cell proliferation and IL-6 and CXCL8 release in healthy individuals (≥ 30 nm) and in nonsevere and severe asthma patients (≥100 nm), with the latter requiring higher concentrations of these mimics. JQ1/SGCBD01 reduced Brd4 binding to IL8 and IL6 promoters induced by FCS+TGF-β. Mimics of BET bromodomains inhibit aberrant ASM cell proliferation and inflammation with lesser efficiency in those from asthmatic patients. They may be effective in reducing airway remodeling in asthma. PMID:25697361

  4. Regulation of H1-receptor coupling and H1-receptor mRNA by histamine in bovine tracheal smooth muscle

    PubMed Central

    Pype, J L; Dupont, L J; Mak, J C W; Barnes, P J; Verleden, G M

    1998-01-01

    Pretreatment of bovine tracheal smooth muscle (BTSM) with histamine (1–100 μM, 1 h) induced a concentration-dependent desensitization of the contractile response to subsequently administered histamine, with a reduction of the maximum response of 72±8% (n=5) following pre-exposure to 100 μM histamine. In contrast, concentration-response curves to the muscarinic agonist, methacholine were not affected following histamine pretreatment, indicating a homologous desensitization. Furthermore, concentration-response curves to NaF, a G-protein activator, were not altered following histamine pre-incubation.The histamine H1-receptor (H1R) desensitization could be antagonized by mepyramine (an H1-receptor antagonist, 1 μM) but not by cimetidine (an H2-receptor antagonist, 10 μM), indicating that the desensitization occurred via stimulation of histamine H1-receptors, without evidence for the involvement of histamine H2-receptors.Indomethacin (10 μM) did not block the H1R desensitization, suggesting no involvement of prostaglandins. Furthermore, histamine pre-incubation in calcium free medium still induced a functional uncoupling of H1R.GF 109203X, a protein kinase C (PKC) inhibitor, and H-7, a non-selective kinase inhibitor, did not antagonize the homologous H1R desensitization.The steady-state level of H1R mRNA, assessed by Northern blot analysis, was not affected by prolonged histamine exposure (100 μM, 0.5, 1, 2, 4, 16 and 24 h).These results suggest that histamine induces desensitization of the H1R at the level of the receptor protein, which involves a mechanism independent of PKC, PKA, PKG and calcium influx, suggesting the involvement of a receptor-specific kinase. PMID:9535029

  5. MiR-138 promotes smooth muscle cells proliferation and migration in db/db mice through down-regulation of SIRT1

    SciTech Connect

    Xu, Juan; Li, Li; Yun, Hui-fang; Han, Ye-shan

    2015-08-07

    Background: Diabetic vascular smooth muscle cells (VSMCs) exhibit significantly increased rates of proliferation and migration, which was the most common pathological change in atherosclerosis. In addition, the study about the role for miRNAs in the regulation of VSMC proliferation is just beginning to emerge and additional miRNAs involved in VSMC proliferation modulation should be identified. Methods: The expression of miR-138 and SIRT1 were examined in SMCs separated from db/db mice and in SMC lines C-12511 exposed to high glucose with qRT-PCR and western blot. The regulation of miR-138 on the expression of SMCs was detected with luciferase report assay. VSMCs proliferation and migration assays were performed to examine the effect of miR-138 inhibitor on VSMCs proliferation and migration. Results: We discovered that higher mRNA level of miR-138 and reduced expression of SIRT1 were observed in SMCs separated from db/db mice and in SMC lines C-12511. Moreover, luciferase report assay showed that the activity of SIRT1 3′-UTR was highly increased by miR-138 inhibitor and reduced by miR-138 mimic. In addition, we examined that the up-regulation of NF-κB induced by high glucose in SMCs was reversed by resveratrol and miR-138 inhibitor. MTT and migration assays showed that miR-138 inhibitor attenuated the proliferation and migration of smooth muscle cells. Conclusion: In this study, we revealed that miR-138 might promote proliferation and migration of SMC in db/db mice through suppressing the expression of SIRT1. - Highlights: • Higher mRNA level of miR-138 was observed in SMCs from db/db mice. • The mRNA and protein level of SIRT1 in SMCs from db/db mice were greatly reduced. • miR-138 could regulate the expression of SIRT1 in SMCs. • SIRT1 overexpression reversed the up-regulation of acetylized p65 and NF-κB induced by high glucose. • MiR-138 inhibitor reversed VSMCs proliferation and migration induced by high glucose.

  6. Adenylyl cyclase 2 selectively couples to E prostanoid type 2 receptors, whereas adenylyl cyclase 3 is not receptor-regulated in airway smooth muscle.

    PubMed

    Bogard, Amy S; Adris, Piyatilake; Ostrom, Rennolds S

    2012-08-01

    Adenylyl cyclases (ACs) are important regulators of airway smooth muscle function, because β-adrenergic receptor (βAR) agonists stimulate AC activity and cAMP production. We have previously shown in a number of cell types that AC6 selectively couples to βAR and these proteins are coexpressed in lipid rafts. We overexpressed AC2, AC3, and AC6 in mouse bronchial smooth muscle cells (mBSMCs) and human embryonic kidney (HEK)-293 cells by using recombinant adenoviruses and assessed their localization and regulation by various G protein-coupled receptors (GPCRs). AC3 and AC6 were expressed primarily in caveolin-rich fractions, whereas AC2 expression was excluded from these domains. AC6 expression enhanced cAMP production in response to isoproterenol but did not increase responses to butaprost, reflecting the colocalization of AC6 with β(2)AR but not E prostanoid type 2 receptor (EP(2)R) in lipid raft fractions. AC2 expression enhanced butaprost-stimulated cAMP production but had no effect on the β(2)AR-mediated response. AC3 did not couple to any GPCR tested. Forskolin-induced arborization of mBSMCs was assessed as a functional readout of cAMP signaling. Arborization was enhanced by overexpression of AC6 and AC3, but AC2 had no effect. GPCR-stimulated arborization mirrored the selective coupling observed for cAMP production. With the addition of the phosphodiesterase 4 (PDE4) inhibitor rolipram AC2 accelerated forskolin-stimulated arborization. Thus, AC2 selectively couples to EP(2)R, but signals from this complex are limited by PDE4 activity. AC3 does not seem to couple to GPCR in either mBSMCs or HEK-293 cells, so it probably exists in a distinct signaling domain in these cells.

  7. Positive regulation of the Egr-1/osteopontin positive feedback loop in rat vascular smooth muscle cells by TGF-{beta}, ERK, JNK, and p38 MAPK signaling

    SciTech Connect

    Yu, Hong-Wei; Liu, Qi-Feng; Liu, Gui-Nan

    2010-05-28

    Previous studies identified a positive feedback loop in rat vascular smooth muscle cells (VSMCs) in which early growth response factor-1 (Egr-1) binds to the osteopontin (OPN) promoter and upregulates OPN expression, and OPN upregulates Egr-1 expression via the extracellular signal-regulated protein kinase (ERK) signaling pathway. The current study examined whether transforming growth factor-{beta} (TGF-{beta}) activity contributes to Egr-1 binding to the OPN promoter, and whether other signaling pathways act downstream of OPN to regulate Egr-1 expression. ChIP assays using an anti-Egr-1 antibody showed that amplification of the OPN promoter sequence decreased in TGF-{beta} DNA enzyme-transfected VSMCs relative to control VSMCs. Treatment of VSMCs with PD98059 (ERK inhibitor), SP600125 (JNK inhibitor), or SB203580 (p38 MAPK inhibitor) significantly inhibited OPN-induced Egr-1 expression, and PD98059 treatment was associated with the most significant decrease in Egr-1 expression. OPN-stimulated VSMC cell migration was inhibited by SP600125 or SB203580, but not by PD98059. Furthermore, MTT assays showed that OPN-mediated cell proliferation was inhibited by PD98059, but not by SP600125 or SB203580. Taken together, the results of the current study show that Egr-1 binding to the OPN promoter is positively regulated by TGF-{beta}, and that the p38 MAPK, JNK, and ERK pathways are involved in OPN-mediated Egr-1 upregulation.

  8. Shh mediates PDGF-induced contractile-to-synthetic phenotypic modulation in vascular smooth muscle cells through regulation of KLF4.

    PubMed

    Zeng, Qiu; Wei, Bin; Zhao, Yu; Wang, Xuehu; Fu, Qining; Liu, Hong; Li, Fenghe

    2016-07-01

    Platelet-derived growth factor (PDGF) is known to induce phenotypic switching of vascular smooth muscle cells (VSMCs) from contractile to a pathological synthetic state, which played an essential role in proliferation of VSMCs. Sonic hedgehog (Shh) contributes to the proliferation of VSMCs when induced by PDGF. Here, we investigated the probable role of Shh in PDGF-induced VSMC dedifferentiation and its underlying mechanisms. We found that PDGF stimulated Shh expression in VSMCs, which was mediated by activation of PDGFRβ/ERK1/2 cell signaling pathway. Further, we found PDGF-induced VSMC phenotypic modulation was accompanied by up-regulation of Shh/Gli family zinc finger 2 (Gli2) signaling and Krüppel-like factor 4 (KLF4). When inhibited Shh in the presence of PDGF, the expressions of KLF4 and VSMC dedifferentiation markers were down-regulated and the effect of PDGF in inducing VSMC dedifferentiation was blocked. In the absence of PDGF, Shh signaling activation increased the expression of KLF4 and promoted VSMC dedifferentiation. The results indicate Shh participated in the regulation of PDGF-induced VSMC dedifferentiation. Finally, we found that KLF4 was closely involved in this process. On inhibition of KLF4, PDGF induced VSMC dedifferentiation was abrogated, even in the presence of Shh. Taken together, the results provide critical insights into the newly discovered role of Shh in phenotypic modulation of VSMCs which depends on KLF4.

  9. Endothelial Cells Can Regulate Smooth Muscle Cells in Contractile Phenotype through the miR-206/ARF6&NCX1/Exosome Axis

    PubMed Central

    Lin, Xiao; He, Yu; Hou, Xue; Zhang, Zhenming; Wang, Rui; Wu, Qiong

    2016-01-01

    Active interactions between endothelial cells and smooth muscle cells (SMCs) are critical to maintaining the SMC phenotype. Exosomes play an important role in intercellular communication. However, little is known about the mechanisms that regulate endothelial cells and SMCs crosstalk. We aimed to determine the mechanisms underlying the regulation of the SMC phenotype by human umbilical vein endothelial cells (HUVECs) through exosomes. We found that HUVECs overexpressing miR-206 upregulated contractile marker (α-SMA, Smoothelin and Calponin) mRNA expression in SMCs. We also found that the expression of miR-206 by HUVECs reduced exosome production by regulating ADP-Ribosylation Factor 6 (ARF6) and sodium/calcium exchanger 1 (NCX1). Using real-time PCR and western blot analysis, we showed that HUVEC-derived exosomes decreased the expression of contractile phenotype marker genes (α-SMA, Smoothelin and Calponin) in SMCs. Furthermore, a reduction of the miR-26a-containing exosomes secreted from HUVECs affects the SMC phenotype. We propose a novel mechanism in which miR-206 expression in HUVECs maintains the contractile phenotype of SMCs by suppressing exosome secretion from HUVECs, particularly miR-26a in exosomes, through targeting ARF6 and NCX1. PMID:27031991

  10. Regulation of cell calcium and contractility in mammalian arterial smooth muscle: the role of sodium-calcium exchange.

    PubMed Central

    Ashida, T; Blaustein, M P

    1987-01-01

    1. The contraction and relaxation of rings of rat thoracic aorta and bovine tail artery were examined as a function of changes in the Na+ electrochemical gradient in order to determine the role of Na-Ca exchange in the control of contractility. 2. Inhibition of the Na+ pump in rat aorta by K+-free media or a low concentration (5 x 10(-5) M) of strophanthidin reversibly increased the contractile responses to caffeine and noradrenaline. These effects were dependent upon external Ca2+ and were observed even in the presence of a Ca2+ channel blocker (10 microM-verapamil or 10 microM-diltiazem) and an alpha-receptor blocker (10 microM-phentolamine). 3. Reduction of external Na+ concentration, [Na+]o (replaced by N-methylglucamine, tetramethylammonium or Tris), also caused an external Ca2+-dependent increase in tonic tension and, in rat aorta, an increase in the response to caffeine. These effects were also observed in the presence of verapamil and phentolamine. 4. Caffeine relaxed the bovine tail artery, but increased the sensitivity of the rat aorta to reduced [Na+]o. The latter effect was presumably due to block of Ca2+ sequestration in the sarcoplasmic reticulum, so that entering Ca2+ was more effective in raising the intracellular free Ca2+ level, [Ca2+]i. 5. Relaxation from K+-free or low-Na+ contractions, in Ca2+-free media, depended upon [Na+]o. Reduction of [Na+]o to 1.2 or 7.5 mM slowed the relaxation of rat aorta (5 mM-caffeine present) 3- to 5-fold, and the relaxation of bovine tail artery (without caffeine) 5- to 10-fold. These effects were seen in the presence of verapamil and phentolamine. 6. These observations are all consistent with an Na-Ca exchange transport system that can move Ca2+ either into or out of the arterial smooth muscle cells. Ca2+ entry is enhanced by raising [Na+]i (by Na+ pump inhibition) and/or lowering [Na+]o. Ca2+ extrusion from the contracted muscles is largely dependent upon external Na+. The latter observation implies that, when

  11. [UTP regulates spontaneous transient outward currents in porcine coronary artery smooth muscle cells through PLC-IP(3) signaling pathway].

    PubMed

    Li, Peng-Yun; Zeng, Xiao-Rong; Yang, Yan; Cai, Fang; Li, Miao-Ling; Liu, Zhi-Fei; Pei, Jie; Zhou, Wen

    2008-02-25

    The aim of the present study was to investigate the effects of inositol 1,4,5-trisphosphate (IP(3))-generating agonist UTP on spontaneous transient outward currents (STOCs), and explore the role of intracellular Ca(2+) release in the current response mediated by IP(3) in porcine coronary artery smooth muscle cells (CASMCs). The coronary artery was excised from the fresh porcine heart and cut into small segments (2 mm × 5 mm) and then transferred to enzymatic dissociation solution for incubation. Single CASMCs were obtained by two-step enzyme digestion at 37 °C. STOCs were recorded and characterized using the perforated whole-cell patch-clamp configuration in freshly isolated porcine CASMCs. The currents were amplified and filtered by patch-clamp amplifier (Axopatch 200B), and then the digitized data were recorded by pClamp 9.0 software and further analyzed by MiniAnalysis 6.0 program. The results were as follows: (1) UTP led to conspicuous increases in STOC amplitude by (57.54±5.34)% and in frequency by (77.46±8.42)% (P<0.01, n=38). (2) The specific blocker of phospholipase C (PLC) - U73122 (5 μmol/L) remarkably reduced STOC amplitude by (31.04±7.46)% and frequency by (41.65±16.59)%, respectively (P<0.05, n=10). In the presence of U73122, UTP failed to reactivate STOCs (n=7). (3) Verapamil (20 μmol/L) and CdCl2 (200 μmol/L), two blockers of L-type voltage-dependent Ca(2+) channels, had little effects on STOCs initiated by UTP (n=8). (4) 1 μmol/L bisindolylmaleimide I (BisI), a potent blocker of protein kinase C (PKC), significantly increased STOC amplitude by (65.44±24.66)% and frequency by (61.35±21.47)% (P<0.01, n=12); UTP (40 μmol/L), applied in the presence of 1 μmol/L BisI, could further increase STOC activity (P<0.05, P<0.01, n=12). Subsequent application of ryanodine (50 μmol/L) abolished STOC activity. (5) In the presence of UTP (40 μmol/L), inhibition of IP(3) receptors (IP(3)Rs) by 2-aminoethoxydiphenyl borate (2-APB, 40 μmol/L) reduced

  12. Large-conductance voltage- and Ca2+-activated K+ channel regulation by protein kinase C in guinea pig urinary bladder smooth muscle.

    PubMed

    Hristov, Kiril L; Smith, Amy C; Parajuli, Shankar P; Malysz, John; Petkov, Georgi V

    2014-03-01

    Large-conductance voltage- and Ca(2+)-activated K(+) (BK) channels are critical regulators of detrusor smooth muscle (DSM) excitability and contractility. PKC modulates the contraction of DSM and BK channel activity in non-DSM cells; however, the cellular mechanism regulating the PKC-BK channel interaction in DSM remains unknown. We provide a novel mechanistic insight into BK channel regulation by PKC in DSM. We used patch-clamp electrophysiology, live-cell Ca(2+) imaging, and functional studies of DSM contractility to elucidate BK channel regulation by PKC at cellular and tissue levels. Voltage-clamp experiments showed that pharmacological activation of PKC with PMA inhibited the spontaneous transient BK currents in native freshly isolated guinea pig DSM cells. Current-clamp recordings revealed that PMA significantly depolarized DSM membrane potential and inhibited the spontaneous transient hyperpolarizations in DSM cells. The PMA inhibitory effects on DSM membrane potential were completely abolished by the selective BK channel inhibitor paxilline. Activation of PKC with PMA did not affect the amplitude of the voltage-step-induced whole cell steady-state BK current or the single BK channel open probability (recorded in cell-attached mode) upon inhibition of all major Ca(2+) sources for BK channel activation with thapsigargin, ryanodine, and nifedipine. PKC activation with PMA elevated intracellular Ca(2+) levels in DSM cells and increased spontaneous phasic and nerve-evoked contractions of DSM isolated strips. Our results support the concept that PKC activation leads to a reduction of BK channel activity in DSM via a Ca(2+)-dependent mechanism, thus increasing DSM contractility.

  13. Transcriptional regulation of NADPH oxidase isoforms, Nox1 and Nox4, by nuclear factor-{kappa}B in human aortic smooth muscle cells

    SciTech Connect

    Manea, Adrian; Tanase, Laurentia I.; Raicu, Monica; Simionescu, Maya

    2010-06-11

    Inflammation-induced changes in the activity and expression of NADPH oxidases (Nox) play a key role in atherogenesis. The molecular mechanisms of Nox regulation are scantily elucidated. Since nuclear factor-{kappa}B (NF-{kappa}B) controls the expression of many genes associated to inflammation-related diseases, in this study we have investigated the role of NF-{kappa}B signaling in the regulation of Nox1 and Nox4 transcription in human aortic smooth muscle cells (SMCs). Cultured cells were exposed to tumor necrosis factor-{alpha} (TNF{alpha}), a potent inducer of both Nox and NF-{kappa}B, up to 24 h. Lucigenin-enhanced chemiluminescence and dichlorofluorescein assays, real-time polymerase chain reaction, and Western blot analysis showed that inhibition of NF-{kappa}B pathway reduced significantly the TNF{alpha}-dependent up-regulation of Nox-derived reactive oxygen species production, Nox1 and Nox4 expression. In silico analysis indicated the existence of typical NF-{kappa}B elements in the promoters of Nox1 and Nox4. Transient overexpression of p65/NF-{kappa}B significantly increased the promoter activities of both isoforms. Physical interaction of p65/NF-{kappa}B proteins with the predicted sites was demonstrated by chromatin immunoprecipitation assay. These findings demonstrate that NF-{kappa}B is an essential regulator of Nox1- and Nox4-containing NADPH oxidase in SMCs. Elucidation of the complex relationships between NF-{kappa}B and Nox enzymes may lead to a novel pharmacological strategy to reduce both inflammation and oxidative stress in atherosclerosis and its associated complications.

  14. MicroRNA-31 controls phenotypic modulation of human vascular smooth muscle cells by regulating its target gene cellular repressor of E1A-stimulated genes

    SciTech Connect

    Wang, Jie; Yan, Cheng-Hui; Li, Yang; Xu, Kai; Tian, Xiao-Xiang; Peng, Cheng-Fei; Tao, Jie; Sun, Ming-Yu; Han, Ya-Ling

    2013-05-01

    Phenotypic modulation of vascular smooth muscle cells (VSMCs) plays a critical role in the pathogenesis of a variety of proliferative vascular diseases. The cellular repressor of E1A-stimulated genes (CREG) has been shown to play an important role in phenotypic modulation of VSMCs. However, the mechanism regulating CREG upstream signaling remains unclear. MicroRNAs (miRNAs) have recently been found to play a critical role in cell differentiation via target-gene regulation. This study aimed to identify a miRNA that binds directly to CREG, and may thus be involved in CREG-mediated VSMC phenotypic modulation. Computational analysis indicated that miR-31 bound to the CREG mRNA 3′ untranslated region (3′-UTR). miR-31 was upregulated in quiescent differentiated VSMCs and downregulated in proliferative cells stimulated by platelet-derived growth factor and serum starvation, demonstrating a negative relationship with the VSMC differentiation marker genes, smooth muscle α-actin, calponin and CREG. Using gain-of-function and loss-of-function approaches, CREG and VSMC differentiation marker gene expression levels were shown to be suppressed by a miR-31 mimic, but increased by a miR-31 inhibitor at both protein and mRNA levels. Notably, miR-31 overexpression or inhibition affected luciferase expression driven by the CREG 3′-UTR containing the miR-31 binding site. Furthermore, miR-31-mediated VSMC phenotypic modulation was inhibited in CREG-knockdown human VSMCs. We also determined miR-31 levels in the serum of patients with coronary artery disease (CAD), with or without in stent restenosis and in healthy controls. miR-31 levels were higher in the serum of CAD patients with restenosis compared to CAD patients without restenosis and in healthy controls. In summary, these data demonstrate that miR-31 not only directly binds to its target gene CREG and modulates the VSMC phenotype through this interaction, but also can be an important biomarker in diseases involving VSMC

  15. Glycolaldehyde-derived advanced glycation end products (glycol-AGEs)-induced vascular smooth muscle cell dysfunction is regulated by the AGES-receptor (RAGE) axis in endothelium.

    PubMed

    Nam, Mi-Hyun; Son, Won-Rak; Lee, Young Sik; Lee, Kwang-Won

    Advanced glycation end-products (AGEs) are involved in the development of vascular smooth muscle cell (VSMC) dysfunction and the progression of atherosclerosis. However, AGEs may indirectly affect VSMCs via AGEs-induced signal transduction between monocytes and human umbilical endothelial cells (HUVECs), rather than having a direct influence. This study was designed to elucidate the signaling pathway underlying AGEs-RAGE axis influence on VSMC dysfunction using a co-culture system with monocytes, HUVECs and VSMCs. AGEs stimulated production of reactive oxygen species and pro-inflammatory mediators such as tumor necrosis factor-α and interleukin-1β via extracellular-signal-regulated kinases phosphorylation and nuclear factor-κB activation in HUVECs. It was observed that AGEs-induced pro-inflammatory cytokines increase VSMC proliferation, inflammation and vascular remodeling in the co-culture system. This result implies that RAGE plays a role in AGEs-induced VSMC dysfunction. We suggest that the regulation of signal transduction via the AGEs-RAGE axis in the endothelium can be a therapeutic target for preventing atherosclerosis.

  16. Olive Oil Polyphenols Differentially Inhibit Smooth Muscle Cell Proliferation through a G1/S Cell Cycle Block Regulated by ERK1/2

    PubMed Central

    Abe, Rei; Beckett, Joel; Abe, Ryuzo; Nixon, Alexander; Rochier, Adrienne; Yamashita, Norio; Sumpio, Bauer

    2012-01-01

    We hypothesized that polyphenols contained in olive oil play a role in reducing the risk of atherosclerosis. The aim of this study was to determine if the polyphenols in olive oil, oleuropein (Ole), hydroxytyrosol (HT), and tyrosol (Tyr) could inhibit smooth muscle cell (SMC) proliferation through its influence on cell cycle regulation. Bovine vascular SMC were cultured in the presence of Ole, HT, or Tyr at concentration of 1, 10, or 100 μmol/L. On days 1, 3, and 5, numbers of cells were counted. Cell cycle analysis was performed by flow cytometry on day 1 after SMC were stained with propidium iodide. Cell populations grown in the presence of Ole or HT at 100 μmol/L concentration were significantly inhibited after 5 days of exposure. Tyr had a similar tendency but it did not attain significance. Cell cycle analysis revealed that 66% of cells were in G1 phase in Ole group, compared with 48% in control group. To examine the cell cycle block between G1 and S phases, we performed Western blotting and found that ERK1/2 activation was inhibited by Ole or HT. We conclude that olive oil polyphenols could inhibit SMC proliferation through a cell cycle block between G1 and S phases which may be regulated by ERK1/2. These results demonstrate a mechanism by which olive oil consumption may be atheroprotective by inhibiting SMC proliferation. PMID:23730132

  17. Oxidized low-density lipoprotein promotes osteoblast differentiation in primary cultures of vascular smooth muscle cells by up-regulating Osterix expression in an Msx2-dependent manner.

    PubMed

    Taylor, Jesse; Butcher, Martin; Zeadin, Melec; Politano, Amanda; Shaughnessy, Stephen G

    2011-02-01

    We have previously shown that oxidized low-density lipoproteins (oxLDLs) act synergistically with β-glycerophosphate to induce the osteogenic differentiation of primary bovine aortic smooth muscle cells (BASMCs). In the present study, we attempt to resolve the mechanism responsible for this effect by examining the expression of several osteoblast-specific transcription factors. Thus, by culturing BASMCs in the absence or presence of β-glycerophosphate and/or oxLDL, we demonstrate that β-glycerophosphate induces both Runx2 and Osterix (Osx) expression. In contrast, oxLDL has no effect on Runx2 expression but rather it enhances β-glycerophosphate-induced osteoblast differentiation by further up-regulating Osx expression. In an attempt to elucidate the mechanism responsible for this latter effect, we examined the ability of oxLDL to affect Msh homeobox 2 (Msx2) expression. Similar to its effect on Osx expression, oxLDL was found to synergistically enhance β-glycerophosphate-induced Msx2 expression in an extracellular signal-regulated kinase 1 and 2 (Erk 1 and 2)-dependent manner. Furthermore, oxLDL's ability to enhance both β-glycerophosphate-induced Osx expression and alkaline phosphatase activity was prevented when the BASMCs were first transfected with Msx2-specific siRNA. Taken together, these findings suggest a plausible mechanism by which oxLDL may promote osteoblast differentiation and vascular calcification in vivo.

  18. Hydrogen sulfide potentiates interleukin-1{beta}-induced nitric oxide production via enhancement of extracellular signal-regulated kinase activation in rat vascular smooth muscle cells

    SciTech Connect

    Jeong, Sun-Oh; Pae, Hyun-Ock; Oh, Gi-Su; Jeong, Gil-Saeng; Lee, Bok-Soo; Lee, Seoul; Kim, Du Yong; Rhew, Hyun Yul; Lee, Kang-Min; Chung, Hun-Taeg . E-mail: htchung@wonkwang.ac.kr

    2006-07-07

    Hydrogen sulfide (H{sub 2}S) and nitric oxide (NO) are endogenously synthesized from L-cysteine and L-arginine, respectively. They might constitute a cooperative network to regulate their effects. In this study, we investigated whether H{sub 2}S could affect NO production in rat vascular smooth muscle cells (VSMCs) stimulated with interleukin-1{beta} (IL-1{beta}). Although H{sub 2}S by itself showed no effect on NO production, it augmented IL-{beta}-induced NO production and this effect was associated with increased expression of inducible NO synthase (iNOS) and activation of nuclear factor (NF)-{kappa}B. IL-1{beta} activated the extracellular signal-regulated kinase 1/2 (ERK1/2), and this activation was also enhanced by H{sub 2}S. Inhibition of ERK1/2 activation by the selective inhibitor U0126 inhibited IL-1{beta}-induced NF-{kappa}B activation, iNOS expression, and NO production either in the absence or presence of H{sub 2}S. Our findings suggest that H{sub 2}S enhances NO production and iNOS expression by potentiating IL-1{beta}-induced NF-{kappa}B activation through a mechanism involving ERK1/2 signaling cascade in rat VSMCs.

  19. cGMP-dependent protein kinase and the regulation of vascular smooth muscle cell gene expression: possible involvement of Elk-1 sumoylation.

    PubMed

    Choi, ChungSik; Sellak, Hassan; Brown, Felricia M; Lincoln, Thomas M

    2010-11-01

    Although the regulation of smooth muscle cell (SMC) gene expression by cGMP-dependent protein kinase (PKG) is now recognized, the mechanisms underlying these effects are not fully understood. In this study, we report that PKG-I stimulates myocardin/serum response factor (SRF)-dependent gene expression in vascular SMCs. The expression of PKG in PKG-deficient cells enhanced myocardin-induced SM22 promoter activity in a concentration-dependent fashion. However, neither SRF nor myocardin expression was affected. To investigate alternative mechanisms, we examined whether PKG affects the phosphorylation of E26-like protein-1 (Elk-1), a SRF/myocardin transcription antagonist. The activation of PKG caused an increase in a higher molecular mass form of phospho-Elk-1 that was determined to be small ubiquitin-related modifier (sumo)ylated Elk-1. PKG increased Elk-1 sumoylation twofold compared with the PKG-deficient cells, and Elk-1 sumoylation was reduced using dominant-negative sumo-conjugating enzyme, DN-Ubc9, confirming PKG-dependent sumoylation of phospho-Elk-1 in vascular SMCs. In addition, PKG stimulated Elk-1 sumoylation in COS-7 cells overexpressing Elk-1, sumo-1, and PKG-I. The increased expression of PKG in vascular SMCs inhibited Elk-1 binding to SMC-specific promoters, SM22 and smooth muscle myosin heavy chain, as measured by EMSA and chromatin immunoprecipitation assay, and PKG suppressed the Elk-1 inhibition of SM22 reporter gene expression. Taken together, these data suggest that PKG-I decreases Elk-1 activity by sumo modification of Elk-1, thereby increasing myocardin-SRF activity on SMC-specific gene expression.

  20. In vitro expression of the alpha-smooth muscle actin isoform by rat lung mesenchymal cells: regulation by culture condition and transforming growth factor-beta.

    PubMed

    Mitchell, J J; Woodcock-Mitchell, J L; Perry, L; Zhao, J; Low, R B; Baldor, L; Absher, P M

    1993-07-01

    alpha-Smooth muscle actin (alpha SM actin)-containing cells recently have been demonstrated in intraalveolar lesions in both rat and human tissues following lung injury. In order to develop model systems for the study of such cells, we examined cultured lung cell lines for this phenotype. The adult rat lung fibroblast-like "RL" cell lines were found to express alpha SM actin mRNA and protein and to organize this actin into stress fiber-like structures. Immunocytochemical staining of subclones of the RL87 line demonstrated the presence in the cultures of at least four cell phenotypes, one that fails to express alpha SM actin and three distinct morphologic types that do express alpha SM actin. The proportion of cellular actin that is the alpha-isoform was modulated by the culture conditions. RL cells growing at low density expressed minimal alpha SM actin. On reaching confluent densities, however, alpha SM actin increased to at least 20% of the total actin content. This effect, combined with the observation that the most immunoreactive cells were those that displayed overlapping cell processes in culture, suggests that cell-cell contact may be involved in actin isoform regulation in these cells. Similar to the response of some smooth muscle cell lines, alpha SM actin expression in RL cells also was promoted by conditions, e.g., maintenance in low serum medium, which minimize cell division. alpha SM actin expression was modulated in RL cells by the growth factor transforming growth factor-beta. Addition of this cytokine to growing cells substantially elevated the proportion of alpha SM actin protein.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Effect of Flow on Gene Regulation in Smooth Muscle Cells and Macromolecular Transport Across Endothelial Cell Monolayers

    NASA Technical Reports Server (NTRS)

    McIntire, Larry V.; Wagner, John E.; Papadaki, Maria; Whitson, Peggy A.; Eskin, Suzanne G.

    1996-01-01

    Endothelial cells line all of the vessels of the circulatory system, providing a non-thrombogenic conduit for blood flow; they regulate many complex functions in the vasculature, such as coagulation, fibrinolysis, platelet aggregation, vessel tone and growth, and leukocyte traffic; and they form the principal barrier to transport of substances between the blood and the surrounding tissue space. The permeability of endothelial cell changes with environmental stimuli; shear stress, in particular, applied either in vivo, or in vitro, induces changes in protein expression and secretion of vasoactive factors by endothelial cells. The ability to study the effects of shear on the macromolecular permeability of the cerebral vasculature is particularly important, since in no other place is the barrier function of the endothelium more important than in the brain. The endothelial cells of this organ have developed special barrier properties that keep the cerebral system from experiencing any drastic change in composition; together with glial cells, they form the blood brain barrier (BBB). We have studied the effect of flow on bovine BBB using flow chambers and tissue culture systems.

  2. MiRNA regulation of TRAIL expression exerts selective cytotoxicity to prostate carcinoma cells.

    PubMed

    Huo, Wei; Jin, Ning; Fan, Li; Wang, Weihua

    2014-03-01

    Prostate carcinoma is the most common cancer for men and among the leading cancer-related causes. Many evidences have shown that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) potently induces apoptosis in cancer cells, and thus, is a promising biologic agent for prostate carcinoma therapy. However, TRAIL expression mediated by the current vectors lacks tumor specificity, thereby exerting cytotoxicity to normal cells. To solve this problem, we inserted miRNA response elements (MREs), miR-143 and miR-145, expression levels of which were reduced in prostate carcinoma, as well as that of miR-122, which is specifically expressed in hepatic cells, into adenoviral vectors to control TRAIL expression (Ad-TRAIL-M3). qPCR data confirmed that miR-143, miR-145, and miR-122 levels were all decreased in prostate carcinoma cell lines and prostate cancer samples from patients. Luciferase assays showed that MREs-regulated luciferase expression was potently suppressed in normal cells, but not in prostate cancer cells. Ad-TRAIL-M3, which expresses TRAIL in a MREs-regulated manner, produced high level of TRAIL and suppressed the survival of prostate cancer cells by inducing apoptosis, while Ad-TRAIL-M3 had no TRAIL expression in normal cells and thus exerted no cytotoxicity to them. The studies on PC-3 tumor xenograft in mice further confirmed that Ad-TRAIL-M3 was able to inhibit the growth of tumors and possessed high biosafety. In conclusion, we successfully generated an adenoviral vector that expresses TRAIL in miRNA-regulated mechanism. This miRNA-based gene therapy may be promising for prostate carcinoma treatment.

  3. Transcriptional up-regulation of antioxidant genes by PPAR{delta} inhibits angiotensin II-induced premature senescence in vascular smooth muscle cells

    SciTech Connect

    Kim, Hyo Jung; Ham, Sun Ah; Paek, Kyung Shin; Hwang, Jung Seok; Jung, Si Young; Kim, Min Young; Jin, Hanna; Kang, Eun Sil; Woo, Im Sun; Kim, Hye Jung; Lee, Jae Heun; Chang, Ki Churl; Han, Chang Woo; Seo, Han Geuk

    2011-03-25

    Research highlights: {yields} Activation of PPAR{delta} by GW501516 significantly inhibited Ang II-induced premature senescence in hVSMCs. {yields} Agonist-activated PPAR{delta} suppressed generation of Ang II-triggered ROS with a concomitant reduction in DNA damage. {yields} GW501516 up-regulated expression of antioxidant genes, such as GPx1, Trx1, Mn-SOD and HO-1. {yields} Knock-down of these antioxidant genes abolished the effects of GW501516 on ROS production and premature senescence. -- Abstract: This study evaluated peroxisome proliferator-activated receptor (PPAR) {delta} as a potential target for therapeutic intervention in Ang II-induced senescence in human vascular smooth muscle cells (hVSMCs). Activation of PPAR{delta} by GW501516, a specific agonist of PPAR{delta}, significantly inhibited the Ang II-induced premature senescence of hVSMCs. Agonist-activated PPAR{delta} suppressed the generation of Ang II-triggered reactive oxygen species (ROS) with a concomitant reduction in DNA damage. Notably, GW501516 up-regulated the expression of antioxidant genes, such as glutathione peroxidase 1, thioredoxin 1, manganese superoxide dismutase and heme oxygenase 1. siRNA-mediated down-regulation of these antioxidant genes almost completely abolished the effects of GW501516 on ROS production and premature senescence in hVSMCs treated with Ang II. Taken together, the enhanced transcription of antioxidant genes is responsible for the PPAR{delta}-mediated inhibition of premature senescence through sequestration of ROS in hVSMCs treated with Ang II.

  4. Ryanodine receptors in smooth muscle.

    PubMed

    Guerrero-Hernández, Agustín; Gómez-Viquez, Leticia; Guerrero-Serna, Guadalupe; Rueda, Angélica

    2002-07-01

    The sarcoplasmic reticulum (SR) of smooth muscle is endowed with two different types of Ca2+ release channels, i.e. inositol 1,4,5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs). In general, both release channels mobilize Ca2+ from the same internal store in smooth muscle. While the importance of IP3Rs in agonist-induced contraction is well established, the role of RyRs in excitation-contraction coupling of smooth muscle is not clear. The participation of smooth muscle RyRs in the amplification of Ca2+ transients induced by either opening of Ca2+-permeable channels or IP3-triggered Ca2+ release has been studied. The efficacy of both processes to activate RyRs by calcium-induced calcium release (CICR) is highly variable and not widely present in smooth muscle. Although RyRs in smooth muscle generate Ca2+ sparks that are similar to those observed in striated muscles, the contribution of these local Ca2+ events to depolarization-induced global rise in [Ca2+]i is rather limited. Recent data suggest that RyRs are involved in regulating the luminal [Ca2+] of SR and also in smooth muscle relaxation. This review summarizes studies that were carried out mainly in muscle strips or in freshly isolated myocytes, and that were aimed to determine the physiological role of RyRs in smooth muscle.

  5. Extracellular magnesium regulates nuclear and perinuclear free ionized calcium in cerebral vascular smooth muscle cells: possible relation to alcohol and central nervous system injury.

    PubMed

    Altura, B M; Zhang, A; Cheng, T P; Altura, B T

    2001-02-01

    Quantitative digital imaging microscopy, confocal laser scanning microscopy (CLSM), and multiple molecular fluorescent probes were utilized to test the hypothesis that cerebral vascular muscle cell nuclear ([Ca(2+)](n)), perinuclear ([Ca(2+)](pn)), and cytoplasmic free calcium ([Ca(2+)](i)) levels are regulated by the concentration of extracellular free magnesium ions ([Mg(2+)](o)). Primary cultured canine cerebral vascular smooth muscle cells were loaded with either fura-2/AM, indo-1/AM, or fluo-3/AM, and the subcellular Ca(2+) responses to stepwise reduction in [Mg(2+)](o) (i.e., from 1.36 to 0.17 mM) were analyzed over time. With normal 1.36 mM [Mg(2+)](o)-containing incubation media, basal mean [Ca(2+)](i) was 89.6+/-15 nM. Lowering [Mg(2+)](o) to 1.07, 0.88, 0.48, and 0.17 mM resulted in rapid (<4 min) increments in [Ca(2+)](i) going to 213+/-43, 368+/-67, 471+/-77, and 642+/-98 nM, respectively; the longer the exposure time (up to 30 min) to lowered [Mg(2+)](o), the higher the [Ca(2+)](i). Restoration of [Mg(2+)](o) to normal caused decreases in [Ca(2+)](i) to 215.9+/-42.3 nM, but only complete removal of [Ca(2+)](o) returned [Ca(2+)](i) to basal levels. Results show that basal [Ca(2+)](pn) (282+/-92 nM) exceeds basal cytoplasmic Ca(2+) (61+/-27.8 nM) and [Ca(2+)](n) (20+/-7.6 nM). However, reduction of normal [Mg(2+)](o) to 0.48 mM resulted in dramatic, rapid rises in all subcellular compartments, where [Ca(2+)](pn) (1503+/-102 nM)>cytoplasmic Ca(2+) (688+/-49 nM) approximately equal to [Ca(2+)](n) (674+/-12 nM). Nuclear Ca(2+) rose dramatically (e.g., 35-40 times basal levels). Both verapamil (1 microM) and Ni(2+) (5 mM) prevented, completely, the rises in Ca(2+) in all compartments, suggesting that Mg(2+)-dependent Ca(2+) accumulation may be dependent on nuclear, endoplasmic reticulum-Golgi, and cytoplasmic L-type voltage membrane-regulated Ca(2+) channels. The normally low [Ca(2+)](n) suggests that Ca(2+) does not transport passively across the nuclear

  6. Adenylate cyclase, cyclic AMP and extracellular-signal-regulated kinase-2 in airway smooth muscle: modulation by protein kinase C and growth serum.

    PubMed Central

    Moughal, N; Stevens, P A; Kong, D; Pyne, S; Pyne, N J

    1995-01-01

    Bradykinin and phorbol 12-myristate 13-acetate stimulate adenylate cyclase activity in serum-depleted cultured airway smooth muscle via a protein kinase C (PKC)-dependent pathway. The probable target is the type II adenylate cyclase, which can integrate coincident signals from both PKC and Gs. Therefore, activation of Gs (by cholera-toxin pre-treatment) amplified the bradykinin-stimulated cyclic AMP signal and concurrently attenuated the partial activation of extracellular-signal-regulated kinase-2 (ERK-2) by bradykinin. We have previously demonstrated that, in order to induce full activation of ERK-2 with bradykinin, it is necessary to obliterate PKC-stimulated cyclic AMP formation. We concluded that the cyclic AMP signal limits the magnitude of ERK-2 activation [Pyne, Moughal, Stevens, Tolan and Pyne (1994) Biochem. J. 304, 611-616]. The present study indicates that the bradykinin-stimulated ERK-2 pathway is entirely cyclic AMP-sensitive, and suggests that coincident signal detection by adenylate cyclase may be an important physiological route for the modulation of early mitogenic signalling. Furthermore, the direct inhibition of adenylate cyclase activity enables bradykinin to induce DNA synthesis, indicating that the PKC-dependent activation of adenylate cyclase limits entry of cells into the cell cycle. These studies suggest that the mitogenicity of an agonist may be governed, in part, by its ability to stimulate an inhibitory cyclic AMP signal pathway in the cell. The activation of adenylate cyclase by PKC appears to be downstream of phospholipase D. However, in cells that were maintained in growth serum (i.e. were not growth-arrested), bradykinin was unable to elicit a PKC-stimulated cyclic AMP response. The lesion in the signal-response coupling was not at the level of either the receptor or phospholipase D, which remain functionally operative and suggests modification occurs at either PKC or adenylate cyclase itself. These studies are discussed with

  7. MicroRNA expression in Epstein-Barr virus-associated post-transplant smooth muscle tumours is related to leiomyomatous phenotype

    PubMed Central

    2013-01-01

    Epstein-Barr virus (EBV)-associated post-transplant smooth muscle tumours (PTSMT) are rare complications. In our previous molecular analysis, we have evaluated the expression of regulatory microRNA which are known to be EBV-related (miR-146a and miR-155) but found no deregulation in PTSMT. In this current analysis, we aimed to characterize the expression profiles of several hundred microRNA. Tissue samples from PTSMT and uterine leiomyomas were analysed by quantitative real-time PCR for the expression of 365 mature microRNA. PTSMT and leiomyomas share a highly similar microRNA profile, e.g. strong expression of miR-143/miR-145 cluster and low expression of miR-200c. Among EBV-related microRNA (miR-10b, miR-21, miR-29b, miR-34a, miR-127, miR-146a, miR-155, miR-200b, miR-203 and miR-429) only miR-10b and miR-203 were significantly deregulated. The expression pattern of microRNA in PTSMT is not associated with EBV infection but reflects the leiomyomatous differentiation of the tumour cells. PMID:23830214

  8. Down-regulation of hsa-miR-148b inhibits vascular smooth muscle cells proliferation and migration by directly targeting HSP90 in atherosclerosis

    PubMed Central

    Zhang, Xinqi; Shi, Hua; Wang, Yuanlin; Hu, Jianxin; Sun, Zhaolin; Xu, Shuxiong

    2017-01-01

    The abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are crucial pathological processes that are involved in atherosclerosis. Growing evidence suggests that microRNAs (miRNAs) play critical roles in VSMCs functions. Here, we analyzed the expression of four atherosclerosis-related miRNAs and found that hsa-miR-148b was significantly down-regulated in plaques from atherosclerotic patients compared to a healthy control group. The restoration of hsa-miR-148b function in cells transfected with a hsa-miR-148b mimicmarkedly inhibited VSMCs proliferation and migration compared to a hsa-miR-148b mimic control. Furthermore, we discovered that heat shock protein 90 (HSP90) was a direct target of hsa-miR-148b in VSMCs. Hsa-miR-148b suppressed HSP90 expression by directly binding its 3’-untranslated region (UTR). In addition, the expression of hsa-miR-148b was negatively correlated with the HSP90 mRNA levels in plaques of atherosclerotic patients. Interestingly, the overexpression of HSP90 partly abrogated the hsa-miR-148b-mediated inhibition of VSMCs proliferation and migration. Our study provides the first evidence that hsa-miR-148b has anti-proliferative and migratory functions by targeting HSP90 in VSMCs and may aidin the development of new biomarkers and potential therapeutic targets for atherosclerosis. PMID:28337290

  9. PPARβ/δ, a Novel Regulator for Vascular Smooth Muscle Cells Phenotypic Modulation and Vascular Remodeling after Subarachnoid Hemorrhage in Rats.

    PubMed

    Zhang, Hongrong; Jiang, Li; Guo, Zongduo; Zhong, Jianjun; Wu, Jingchuan; He, Junchi; Liu, Han; He, Zhaohui; Wu, Haitao; Cheng, Chongjie; Sun, Xiaochuan

    2017-03-22

    Cerebral vascular smooth muscle cell (VSMC) phenotypic switch is involved in the pathophysiology of vascular injury after aneurysmal subarachnoid hemorrhage (aSAH), whereas the molecular mechanism underlying it remains largely speculative. Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) has been implicated to modulate the vascular cells proliferation and vascular homeostasis. In the present study, we investigated the potential role of PPARβ/δ in VSMC phenotypic switch following SAH. Activation of PPARβ/δ by GW0742 and adenoviruses PPARβ/δ (Ad-PPARβ/δ) significantly inhibited hemoglobin-induced VSMC phenotypic switch. However, the effects of PPARβ/δ on VSMC phenotypic switch were partly obstacled in the presence of LY294002, a potent inhibitor of Phosphatidyl-Inositol-3 Kinase-AKT (PI3K/AKT). Furthermore, following study demonstrated that PPARβ/δ-induced PI3K/AKT activation can also contribute to Serum Response Factor (SRF) nucleus localization and Myocardin expression, which was highly associated with VSMC phenotypic switch. Finally, we found that Ad-PPARβ/δ positively modulated vascular remodeling in SAH rats, i.e. the diameter of basilar artery and the thickness of vessel wall. In addition, overexpression of PPARβ/δ by adenoviruses significantly improved neurological outcome. Taken together, this study identified PPARβ/δ as a useful regulator for VSMC phenotypic switch and vascular remodeling following SAH, providing novel insights into the therapeutic strategies of delayed cerebral ischemia.

  10. Comparative studies on troponin, a Ca²⁺-dependent regulator of muscle contraction, in striated and smooth muscles of protochordates.

    PubMed

    Obinata, Takashi; Sato, Naruki

    2012-01-01

    Troponin is well known as a Ca(2+)-dependent regulator of striated muscle contraction and it has been generally accepted that troponin functions as an inhibitor of muscle contraction or actin-myosin interaction at low Ca(2+) concentrations, and Ca(2+) at higher concentrations removes the inhibitory action of troponin. Recently, however, troponin became detectable in non-striated muscles of several invertebrates and in addition, unique troponin that functions as a Ca(2+)-dependent activator of muscle contraction has been detected in protochordate animals, although troponin in vertebrate striated muscle is known as an inhibitor of the contraction in the absence of a Ca(2+). Further studies on troponin in invertebrate muscle, especially in non-striated muscle, would provide new insight into the evolution of regulatory systems for muscle contraction and diverse function of troponin and related proteins. The methodology used for preparation and characterization of functional properties of protochordate striated and smooth muscles will be helpful for further studies of troponin in other invertebrate animals.

  11. PPARβ/δ, a Novel Regulator for Vascular Smooth Muscle Cells Phenotypic Modulation and Vascular Remodeling after Subarachnoid Hemorrhage in Rats

    PubMed Central

    Zhang, Hongrong; Jiang, Li; Guo, Zongduo; Zhong, Jianjun; Wu, Jingchuan; He, Junchi; Liu, Han; He, Zhaohui; Wu, Haitao; Cheng, Chongjie; Sun, Xiaochuan

    2017-01-01

    Cerebral vascular smooth muscle cell (VSMC) phenotypic switch is involved in the pathophysiology of vascular injury after aneurysmal subarachnoid hemorrhage (aSAH), whereas the molecular mechanism underlying it remains largely speculative. Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) has been implicated to modulate the vascular cells proliferation and vascular homeostasis. In the present study, we investigated the potential role of PPARβ/δ in VSMC phenotypic switch following SAH. Activation of PPARβ/δ by GW0742 and adenoviruses PPARβ/δ (Ad-PPARβ/δ) significantly inhibited hemoglobin-induced VSMC phenotypic switch. However, the effects of PPARβ/δ on VSMC phenotypic switch were partly obstacled in the presence of LY294002, a potent inhibitor of Phosphatidyl-Inositol-3 Kinase-AKT (PI3K/AKT). Furthermore, following study demonstrated that PPARβ/δ-induced PI3K/AKT activation can also contribute to Serum Response Factor (SRF) nucleus localization and Myocardin expression, which was highly associated with VSMC phenotypic switch. Finally, we found that Ad-PPARβ/δ positively modulated vascular remodeling in SAH rats, i.e. the diameter of basilar artery and the thickness of vessel wall. In addition, overexpression of PPARβ/δ by adenoviruses significantly improved neurological outcome. Taken together, this study identified PPARβ/δ as a useful regulator for VSMC phenotypic switch and vascular remodeling following SAH, providing novel insights into the therapeutic strategies of delayed cerebral ischemia. PMID:28327554

  12. Non-raft adenylyl cyclase 2 defines a cAMP signaling compartment that selectively regulates IL-6 expression in airway smooth muscle cells: differential regulation of gene expression by AC isoforms.

    PubMed

    Bogard, Amy S; Birg, Anna V; Ostrom, Rennolds S

    2014-04-01

    Adenylyl cyclase (AC) isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions. Most cell types express multiple AC isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses in human bronchial smooth muscle cells (BSMC). Overexpression of AC2, AC3, or AC6 had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes. These data show that different AC isoforms can differentially regulate gene expression. Most notable, overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production by BSMC was induced by Fsk and select G protein-coupled receptor (GPCR) agonists, though IL-6 levels did not directly correlate with global cAMP levels. Treatment with PKA selective 6-Bnz-cAMP or Epac selective 8-CPT-2Me-cAMP cAMP analogs revealed a predominant role for PKA in cAMP-mediated induction of IL-6. IL-6 promoter mutations demonstrated that AP-1 and CRE transcription sites were required for Fsk to stimulate IL-6 expression. Our present study defines an AC2 cAMP signaling compartment that specifically regulates IL-6 expression in BSMC via Epac and PKA and demonstrates that other AC isoforms are excluded from this pool.

  13. Regulation of Guinea Pig Detrusor Smooth Muscle Excitability by 17β-Estradiol: The Role of the Large Conductance Voltage- and Ca2+-Activated K+ Channels.

    PubMed

    Provence, Aaron; Hristov, Kiril L; Parajuli, Shankar P; Petkov, Georgi V

    2015-01-01

    Estrogen replacement therapies have been suggested to be beneficial in alleviating symptoms of overactive bladder. However, the precise regulatory mechanisms of estrogen in urinary bladder smooth muscle (UBSM) at the cellular level remain unknown. Large conductance voltage- and Ca2+-activated K+ (BK) channels, which are key regulators of UBSM function, are suggested to be non-genomic targets of estrogens. This study provides an electrophysiological investigation into the role of UBSM BK channels as direct targets for 17β-estradiol, the principle estrogen in human circulation. Single BK channel recordings on inside-out excised membrane patches and perforated whole cell patch-clamp were applied in combination with the BK channel selective inhibitor paxilline to elucidate the mechanism of regulation of BK channel activity by 17β-estradiol in freshly-isolated guinea pig UBSM cells. 17β-Estradiol (100 nM) significantly increased the amplitude of depolarization-induced whole cell steady-state BK currents and the frequency of spontaneous transient BK currents in freshly-isolated UBSM cells. The increase in whole cell BK currents by 17β-estradiol was eliminated upon blocking BK channels with paxilline. 17β-Estradiol (100 nM) significantly increased (~3-fold) the single BK channel open probability, indicating direct 17β-estradiol-BK channel interactions. 17β-Estradiol (100 nM) caused a significant hyperpolarization of the membrane potential of UBSM cells, and this hyperpolarization was reversed by blocking the BK channels with paxilline. 17β-Estradiol (100 nM) had no effects on L-type voltage-gated Ca2+ channel currents recorded under perforated patch-clamp conditions. This study reveals a new regulatory mechanism in the urinary bladder whereby BK channels are directly activated by 17β-estradiol to reduce UBSM cell excitability.

  14. Glycogen synthase kinase 3{beta} regulation of nuclear factor of activated T-cells isoform c1 in the vascular smooth muscle cell response to injury

    SciTech Connect

    Chow Winsion; Hou Guangpei; Bendeck, Michelle P.

    2008-10-01

    The migration and proliferation of vascular smooth muscle cells (vSMCs) are critical events in neointima formation during atherosclerosis and restenosis. The transcription factor nuclear factor of activated T-cells-isoform c1 (NFATc1) is regulated by atherogenic cytokines, and has been implicated in the migratory and proliferative responses of vSMCs through the regulation of gene expression. In T-cells, calcineurin de-phosphorylates NFATc1, leading to its nuclear import, while glycogen synthase kinase 3 {beta} (GSK3{beta}) phosphorylates NFATc1 and promotes its nuclear export. However, the relationship between NFATc1 and GSK3{beta} has not been studied during SMC migration and proliferation. We investigated this by scrape wounding vSMCs in vitro, and studying wound repair. NFATc1 protein was transiently increased, reaching a peak at 8 h after wounding. Cell fractionation and immunocytochemistry revealed that NFATc1 accumulation in the nucleus was maximal at 4 h after injury, and this was coincident with a significant 9 fold increase in transcriptional activity. Silencing NFATc1 expression with siRNA or inhibition of NFAT with cyclosporin A (CsA) attenuated wound closure by vSMCs. Phospho-GSK3{beta} (inactive) increased to a peak at 30 min after injury, preceding the nuclear accumulation of NFATc1. Overexpression of a constitutively active mutant of GSK3{beta} delayed the nuclear accumulation of NFATc1, caused a 50% decrease in NFAT transcriptional activity, and attenuated vSMC wound repair. We conclude that NFATc1 promotes the vSMC response to injury, and that inhibition of GSK3{beta} is required for the activation of NFAT during wound repair.

  15. Targeting of a novel Ca+2/calmodulin-dependent protein kinase II is essential for extracellular signal-regulated kinase-mediated signaling in differentiated smooth muscle cells.

    PubMed

    Marganski, William A; Gangopadhyay, Samudra S; Je, Hyun-Dong; Gallant, Cynthia; Morgan, Kathleen G

    2005-09-16

    Subcellular targeting of kinases controls their activation and access to substrates. Although Ca2+/calmodulin-dependent protein kinase II (CaMKII) is known to regulate differentiated smooth muscle cell (dSMC) contractility, the importance of targeting in this regulation is not clear. The present study investigated the function in dSMCs of a novel variant of the gamma isoform of CaMKII that contains a potential targeting sequence in its association domain (CaMKIIgamma G-2). Antisense knockdown of CaMKIIgamma G-2 inhibited extracellular signal-related kinase (ERK) activation, myosin phosphorylation, and contractile force in dSMCs. Confocal colocalization analysis revealed that in unstimulated dSMCs CaMKIIgamma G-2 is bound to a cytoskeletal scaffold consisting of interconnected vimentin intermediate filaments and cytosolic dense bodies. On activation with a depolarizing stimulus, CaMKIIgamma G-2 is released into the cytosol and subsequently targeted to cortical dense plaques. Comparison of phosphorylation and translocation time courses indicates that, after CaMKIIgamma G-2 activation, and before CaMKIIgamma G-2 translocation, vimentin is phosphorylated at a CaMKII-specific site. Differential centrifugation demonstrated that phosphorylation of vimentin in dSMCs is not sufficient to cause its disassembly, in contrast to results in cultured cells. Loading dSMCs with a decoy peptide containing the polyproline sequence within the association domain of CaMKIIgamma G-2 inhibited targeting. Furthermore, prevention of CaMKIIgamma G-2 targeting led to significant inhibition of ERK activation as well as contractility. Thus, for the first time, this study demonstrates the importance of CaMKII targeting in dSMC signaling and identifies a novel targeting function for the association domain in addition to its known role in oligomerization.

  16. 7 CFR 51.1870 - Fairly smooth.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Fresh Tomatoes 1 Definitions § 51.1870 Fairly smooth. Fairly smooth means that the tomato...

  17. Mechanism by which nuclear factor-kappa beta (NF-kB) regulates ovine fetal pulmonary vascular smooth muscle cell proliferation.

    PubMed

    Ogbozor, Uchenna D; Opene, Michael; Renteria, Lissette S; McBride, Shaemion; Ibe, Basil O

    2015-09-01

    Platelet activating factor (PAF) modulates ovine fetal pulmonary hemodynamic. PAF acts through its receptors (PAFR) in pulmonary vascular smooth muscle cells (PVSMC) to phosphorylate and induce nuclear translocation of NF-kB p65 leading to PVSMC proliferation. However, the interaction of NF-kB p65 and PAF in the nuclear domain to effect PVSMC cell growth is not clearly defined. We used siRNA-dependent translation initiation arrest to study a mechanism by which NF-kB p65 regulates PAF stimulation of PVSMC proliferation. Our hypotheses are: (a) PAF induces NF-kB p65 DNA binding and (b) NF-kB p65 siRNA attenuates PAF stimulation of PVSMC proliferation. For DNA binding, cells were fed 10 nM PAF with and without PAFR antagonists WEB 2170, CV 3988 or BN 52021 and incubated for 12 h. DNA binding was measured by specific ELISA. For NF-kB p65 siRNA effect, starved cells transfected with the siRNA were incubated for 24 h with and without 10 nM PAF. Cell proliferation was measured by DNA synthesis while expression of NF-kB p65 and PAFR protein was measured by Western blotting. In both studies, the effect of 10% FBS alone was used as the positive control. In general, PAF stimulated DNA binding which was inhibited by PAFR antagonists. siRNAs to NF-kB p65 and PAFR significantly attenuated cell proliferation compared to 10% FBS and PAF effect. Inclusion of PAF in siRNA-treated cells did not reverse inhibitory effect of NF-kB p65 siRNA on DNA synthesis. PAFR expression was inhibited in siRNA-treated cells. These data show that PAF-stimulation of PVSMC proliferation occurs via a PAFR-NF-kB p65 linked pathway.

  18. BK channels in rat and human pulmonary smooth muscle cells are BKα-β1 functional complexes lacking the oxygen-sensitive stress axis regulated exon insert

    PubMed Central

    Detweiler, Neil D.; Song, Li; McClenahan, Samantha J.; Versluis, Rachel J.; Kharade, Sujay V.; Kurten, Richard C.; Rhee, Sung W.

    2016-01-01

    Abstract A loss of K+ efflux in pulmonary arterial smooth muscle cells (PASMCs) contributes to abnormal vasoconstriction and PASMC proliferation during pulmonary hypertension (PH). Activation of high-conductance Ca2+-activated (BK) channels represents a therapeutic strategy to restore K+ efflux to the affected PASMCs. However, the properties of BK channels in PASMCs—including sensitivity to BK channel openers (BKCOs)—are poorly defined. The goal of this study was to compare the properties of BK channels between PASMCs of normoxic (N) and chronic hypoxic (CH) rats and then explore key findings in human PASMCs. Polymerase chain reaction results revealed that 94.3% of transcripts encoding BKα pore proteins in PASMCs from N rats represent splice variants lacking the stress axis regulated exon insert, which confers oxygen sensitivity. Subsequent patch-clamp recordings from inside-out (I-O) patches confirmed a dense population of BK channels insensitive to hypoxia. The BK channels were highly activated by intracellular Ca2+ and the BKCO lithocholate; these responses require BKα-β1 subunit coupling. PASMCs of CH rats with established PH exhibited a profound overabundance of the dominant oxygen-insensitive BKα variant. Importantly, human BK (hBK) channels in PASMCs from human donor lungs also represented the oxygen-insensitive BKα variant activated by BKCOs. The hBK channels showed significantly enhanced Ca2+ sensitivity compared with rat BK channels. We conclude that rat BK and hBK channels in PASMCs are oxygen-insensitive BKα-β1 complexes highly sensitive to Ca2+ and the BKCO lithocholate. BK channels are overexpressed in PASMCs of a rat model of PH and may provide an abundant target for BKCOs designed to restore K+ efflux. PMID:28090300

  19. Microarray analysis of ox-LDL (oxidized low-density lipoprotein)-regulated genes in human coronary artery smooth muscle cells.

    PubMed

    Minta, Joe; Jungwon Yun, James; St Bernard, Rosanne

    2010-01-01

    Recent studies suggest that circulating LDL (low-density lipoproteins) play a central role in the pathogenesis of atherosclerosis, and the oxidized form (ox-LDL) is highly atherogenic. Deposits of ox-LDL have been found in atherosclerotic plaques, and ox-LDL has been shown to promote monocyte recruitment, foam cell formation and the transition of quiescent and contractile vascular SMCs (smooth muscle cells) to the migratory and proliferative phenotype. SMC phenotype transition and hyperplasia are the pivotal events in the pathogenesis of atherosclerosis. To comprehend the complex molecular mechanisms involved in ox-LDL-mediated SMC phenotype transition, we have compared the differential gene expression profiles of cultured quiescent human coronary artery SMCs with cells induced with ox-LDL for 3 and 21 h using Affymetrix HG-133UA cDNA microarray chips. Assignment of the regulated genes into functional groups indicated that several genes involved in metabolism, membrane transport, cell-cell interactions, signal transduction, transcription, translation, cell migration, proliferation and apoptosis were differentially expressed. Our data suggests that the interaction of ox-LDL with its cognate receptors on SMCs modulates the induction of several growth factors and cytokines, which activate a variety of intracellular signalling mechanisms (including PI3K, MAPK, Jak/STAT, sphingosine, Rho kinase pathways) that contribute to SMC transition from the quiescent and contractile phenotype to the proliferative and migratory phenotype. Our study has also identified several genes (including CDC27, cyclin A1, cyclin G2, glypican 1, MINOR, p15 and apolipoprotein) not previously implicated in ox-LDL-induced SMC phenotype transition and substantially extends the list of potential candidate genes involved in atherogenesis.

  20. MicroRNA-146a and -21 cooperate to regulate vascular smooth muscle cell proliferation via modulation of the Notch signaling pathway.

    PubMed

    Cao, Jian; Zhang, Kui; Zheng, Jubing; Dong, Ran

    2015-04-01

    A number of microRNAs (miRs) have been shown to participate in the regulation of vascular smooth muscle cell (VSMC) proliferation, a key step in the formation of atherosclerotic plaque, by targeting certain genes. The aim of the present study was to investigate the roles of miR‑146a and miR‑21 in VSMC growth and to study the underlying mechanisms. The expression levels of four previously reported, differentially expressed microRNAs in atherosclerotic plaque (miR‑146a/b, miR‑21, miR‑34a and miR‑210) were measured in two groups: An atherosclerotic plaque group (n=10) and a normal control group (n=10). Polymerase chain reaction (PCR) analysis revealed that the relative expression levels of miR‑146a and miR‑21 in atherosclerotic plaque samples were significantly upregulated to ~260 and 250%, respectively, compared with those in normal controls. Notch2 and Jag1 were confirmed to be target genes of miR‑146a and miR‑21 through the use of a luciferase assay, PCR and western blot analysis. Additionally, VSMCs transfected with miR‑146a expressed significantly lower levels of Notch2 protein and presented an accelerated cell proliferation, which could be attributed to a reduction in the levels of cell cycle arrest. Cotransfection of miR‑146a and miR‑21 further promoted cell cycle progression in addition to VSMC proliferation. In conclusion, the present study revealed that miR‑146a and miR‑21 were significantly upregulated in atherosclerotic plaque, and cooperated to accelerate VSMC growth and cell cycle progression by targeting Notch2 and Jag1.

  1. Aspirin-induced AMP-activated protein kinase activation regulates the proliferation of vascular smooth muscle cells from spontaneously hypertensive rats

    SciTech Connect

    Sung, Jin Young; Choi, Hyoung Chul

    2011-05-06

    Highlights: {yields} Aspirin-induced AMPK phosphorylation was greater in VSMC from SHR than WKY. {yields} Aspirin-induced AMPK phosphorylation inhibited proliferation of VSMC from SHR. {yields} Low basal AMPK phosphorylation in SHR elicits increased VSMC proliferation. {yields} Inhibition of AMPK restored decreased VSMC proliferation by aspirin in SHR. {yields} Aspirin exerts anti-proliferative effect through AMPK activation in VSMC from SHR. -- Abstract: Acetylsalicylic acid (aspirin), used to reduce risk of cardiovascular disease, plays an important role in the regulation of cellular proliferation. However, mechanisms responsible for aspirin-induced growth inhibition are not fully understood. Here, we investigated whether aspirin may exert therapeutic effects via AMP-activated protein kinase (AMPK) activation in vascular smooth muscle cells (VSMC) from wistar kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Aspirin increased AMPK and acetyl-CoA carboxylase phosphorylation in a time- and dose-dependent manner in VSMCs from WKY and SHR, but with greater efficacy in SHR. In SHR, a low basal phosphorylation status of AMPK resulted in increased VSMC proliferation and aspirin-induced AMPK phosphorylation inhibited proliferation of VSMCs. Compound C, an AMPK inhibitor, and AMPK siRNA reduced the aspirin-mediated inhibition of VSMC proliferation, this effect was more pronounced in SHR than in WKY. In VSMCs from SHR, aspirin increased p53 and p21 expression and inhibited the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. These results indicate that in SHR VSMCs aspirin exerts anti-proliferative effects through the induction of AMPK phosphorylation.

  2. Opiorphin-dependent up-regulation of CD73 (a key enzyme in the adenosine signaling pathway) in corporal smooth muscle cells exposed to hypoxic conditions and in corporal tissue in pre-priapic sickle cell mice

    PubMed Central

    Fu, Shibo; Davies, Kelvin P.

    2015-01-01

    The precise molecular mechanisms underlying priapism associated with sickle cell disease remain to be defined. However, there is increasing evidence that up-regulated activity of the opiorphin and adenosine pathways in corporal tissue, resulting in heighted relaxation of smooth muscle, play an important role in development of priapism. A key enzyme in the adenosine pathway is CD73, an ecto-5-prime-nucleotidase (5-prime-ribonucleotide phosphohydrolase; EC 3.1.3.5) which catalyzes the conversion of adenosine mononucleotides to adenosine. In the present study we investigated how sickle cell disease and hypoxia regulate the interplay between opiorphin and CD73. In the corpora of sickle cell mice we observed significantly elevated expression of both the mouse opiorphin homologue mSmr3a (14-fold) and CD73 (2.2-fold) relative to non-sickle cell controls at a life-stage prior to the exhibition of priapism. Sickle cell disease has a pronounced hypoxic component, therefore we determined if CD73 was also modulated in in vitro corporal smooth muscle (CSM) models of hypoxia. Hypoxia significantly increased CD73 protein and mRNA expression by 1.5-fold and 2-fold, respectively. We previously demonstrated that expression of another component of the adenosine signaling pathway, the adensosine 2B receptor, can be regulated by sialorphin (the rat opiorphin homolologue), and we demonstrate that sialorphin also regulates CD73 expression in a dose and time dependent fashion. Using siRNA to knock-down sialorphin mRNA expression in CSM cells in vitro, we demonstrate that the hypoxic up-regulation of CD73 is dependent on the up-regulation of sialorphin. Overall our data provides further evidence to support a role for opiorphin in CSM in regulating the cellular response regulating response to hypoxia or sickle cell disease by activating smooth muscle relaxant pathways. PMID:25833166

  3. Involvement of inositol 1,4,5-trisphosphate formation in the voltage-dependent regulation of the Ca(2+) concentration in porcine coronary arterial smooth muscle cells.

    PubMed

    Yamamura, Hisao; Ohya, Susumu; Muraki, Katsuhiko; Imaizumi, Yuji

    2012-08-01

    The involvement of inositol 1,4,5-trisphosphate (IP(3)) formation in the voltage-dependent regulation of intracellular Ca(2+) concentration ([Ca(2+)](i)) was examined in smooth muscle cells of the porcine coronary artery. Slow ramp depolarization from -90 to 0 mV induced progressive [Ca(2+)](i) increase. The slope was reduced or increased in the presence of Cd(2+) or (±)-1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-[trifluoromethyl]-phenyl)pyridine-3-carboxlic acid methyl ester (Bay K 8644), respectively. The decrease in [Ca(2+)](i) via the membrane hyperpolarization induced by K(+) channel openers (levcromakalim and Evans blue) under current clamp was identical to that under voltage clamp. The step hyperpolarization from -40 to -80 mV reduced [Ca(2+)](i) uniformly over the whole-cell area with a time constant of ∼10 s. The [Ca(2+)](i) at either potential was unaffected by heparin, an inhibitor of IP(3) receptors. Alternatively, [Ca(2+)](i) rapidly increased in the peripheral regions by depolarization from -80 to 0 mV and stayed at that level (∼400 nM) during a 60-s pulse. When the pipette solution contained IP(3) pathway blockers [heparin, 2-aminoethoxydiphenylborate, xestospongin C, or 1-[6-[((17β)-3-methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl]-1H-pyrrole-2,5-dione (U73122)], the peak [Ca(2+)](i) was unchanged, but the sustained [Ca(2+)](i) was gradually reduced by ∼250 nM within 30 s. In the presence of Cd(2+), a long depolarization period slightly increased the [Ca(2+)](i), which was lower than that in the presence of heparin alone. In coronary arterial myocytes, the sustained increase in the [Ca(2+)](i) during depolarization was partly caused by the Ca(2+) release mediated by the enhanced formation of IP(3). The initial [Ca(2+)](i) elevation triggered by the Ca(2+) influx though voltage-dependent Ca(2+) channels may be predominantly responsible for the activation of phospholipase C for IP(3) formation.

  4. Sulfur Dioxide Inhibits Extracellular Signal-regulated Kinase Signaling to Attenuate Vascular Smooth Muscle Cell Proliferation in Angiotensin II-induced Hypertensive Mice

    PubMed Central

    Wu, Hui-Juan; Huang, Ya-Qian; Chen, Qing-Hua; Tian, Xiao-Yu; Liu, Jia; Tang, Chao-Shu; Jin, Hong-Fang; Du, Jun-Bao

    2016-01-01

    Background: Clarifying the mechanisms underlying vascular smooth muscle cell (VSMC) proliferation is important for the prevention and treatment of vascular remodeling and the reverse of hyperplastic lesions. Previous research has shown that the gaseous signaling molecule sulfur dioxide (SO2) inhibits VSMC proliferation, but the mechanism for the inhibition of the angiotensin II (AngII)-induced VSMC proliferation by SO2 has not been fully elucidated. This study was designed to investigate if SO2 inhibited VSMC proliferation in mice with hypertension induced by AngII. Methods: Thirty-six male C57 mice were randomly divided into control, AngII, and AngII + SO2 groups. Mice in AngII group and AngII + SO2 group received a capsule-type AngII pump implanted under the skin of the back at a slow-release dose of 1000 ng·kg−1·min−1. In addition, mice in AngII + SO2 received intraperitoneal injections of SO2 donor. Arterial blood pressure of tail artery was determined. The thickness of the aorta was measured by elastic fiber staining, and proliferating cell nuclear antigen (PCNA) and phosphorylated-extracellular signal-regulated kinase (P-ERK) were detected in aortic tissues. The concentration of SO2 in serum and aortic tissue homogenate supernatant was measured using high-performance liquid chromatography with fluorescence determination. In the in vitro study, VSMC of A7R5 cell lines was divided into six groups: control, AngII, AngII + SO2, PD98059 (an inhibitor of ERK phosphorylation), AngII + PD98059, and AngII + SO2 + PD98059. Expression of PCNA, ERK, and P-ERK was determined by Western blotting. Results: In animal experiment, compared with the control group, AngII markedly increased blood pressure (P < 0.01) and thickened the aortic wall in mice (P < 0.05) with an increase in the expression of PCNA (P < 0.05). SO2, however, reduced the systemic hypertension and the wall thickness induced by AngII (P < 0.05). It inhibited the increased expression of PCNA and P

  5. Developmentally regulated changes in extracellular matrix in endothelial and smooth muscle cells in the ductus arteriosus may be related to intimal proliferation

    SciTech Connect

    Boudreau, N.; Rabinovitch, M. )

    1991-02-01

    In the late gestation fetal lamb ductus arteriosus (DA), intimal proliferation is observed, characterized by smooth muscle migration and proliferation in the subendothelium. The nature of changes in the endothelial and smooth muscle extracellular matrix associated with the development of this feature are not known. We assessed the production of glycoproteins (fibronectin, laminin, and type IV collagen) and glycosaminoglycans (GAGs) (hyaluronic acid, heparan sulfate, and chondroitin sulfate) in endothelial and smooth muscle cells harvested from the DA, aorta (Ao), and pulmonary artery of fetal lambs at 100 days gestation, before the appearance of DA intimal proliferation, and at 138 days, when well-developed intimal cushions are seen. In passage 3 cells, glycoprotein synthesis was measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after 48 hours incubation with (35S)methionine, and GAGs were assessed by labeling with (3H) glucosamine and separation on DEAE ion-exchange high performance liquid chromatography. Analyses were carried out on culture medium, cell layer, and solubilized matrix. Fibronectin secretion by DA smooth muscle cells from 100-day lambs was found to be twice that of Ao or pulmonary artery cells. No significant differences were seen in smooth muscle cells from 138-day lambs or when comparing endothelial cells from each of the vascular sites at both gestational ages. As well, there were no DA-specific differences in laminin or type IV collagen. No significant differences in endothelial GAG secretion were observed comparing each vascular site at both gestational ages. Analysis of endothelial-derived matrices, however, revealed increased incorporation of hyaluronic acid in the DA from 100-day lambs, 10-fold that of the pulmonary artery and Ao, and increased heparan sulfate.

  6. Role of plasminogen activator inhibitor in the reciprocal regulation of bovine aortic endothelial and smooth muscle cell migration by TGF-beta 1.

    PubMed Central

    Petzelbauer, E.; Springhorn, J. P.; Tucker, A. M.; Madri, J. A.

    1996-01-01

    Vascular endothelial and smooth muscle cells exhibit reciprocal migratory responses after transforming growth factor (TGF)-beta 1 treatment. Endothelial cells exhibit a decreased migratory rate and smooth muscle cells exhibit an increased migratory rate. Previous studies have demonstrated increases in extracellular matrix and integrin synthesis and expression in response to TGF-beta 1. In this report, we illustrate the roles of plasminogen activator inhibitor in modulating the migratory rates in these two cell types. Endothelial cells appear to require a proteolytic phenotype for rapid migration, whereas vascular smooth muscle cells appear to require an anti-proteolytic phenotype. Modulation of proteinase/anti-proteinase activity ratios was accomplished via TGF-beta 1 induction, addition of exogenous plasminogen activator inhibitor, addition of anti-catalytic antibodies directed against urokinase plasminogen activator, overexpression of plasminogen activator inhibitor utilizing stable transfectants, and the use of vitronectin as a substratum. The reciprocal migratory behaviors exhibited by these two vascular cell types in response to TGF-beta 1 is discussed in the context that these two vascular cell types utilize distinct adhesive and signaling pathways in their interactions with extracellular matrix components and responsiveness to proteolytic activity. Images Figure 1 Figure 2 Figure 3 PMID:8780396

  7. Role of protein kinase C in phospholemman mediated regulation of α₂β₁ isozyme of Na⁺/K⁺-ATPase in caveolae of pulmonary artery smooth muscle cells.

    PubMed

    Dey, Kuntal; Roy, Soumitra; Ghosh, Biswarup; Chakraborti, Sajal

    2012-04-01

    We have recently reported that α(2)β(1) and α(1)β(1) isozymes of Na(+)/K(+)-ATPase (NKA) are localized in the caveolae whereas only the α(1)β(1) isozyme of NKA is localized in the non-caveolae fraction of pulmonary artery smooth muscle cell membrane. It is well known that different isoforms of NKA are regulated differentially by PKA and PKC, but the mechanism is not known in the caveolae of pulmonary artery smooth muscle cells. Herein, we examined whether this regulation occurs through phospholemman (PLM) in the caveolae. Our results suggest that PKC mediated phosphorylation of PLM occurs only when it is associated with the α(2) isoform of NKA, whereas phosphorylation of PLM by PKA occurs when it is associated with the α(1) isoform of NKA. To investigate the mechanism of regulation of α(2) isoform of NKA by PKC-mediated phosphorylation of PLM, we have purified PLM from the caveolae and reconstituted into the liposomes. Our result revealed that (i) in the reconstituted liposomes phosphorylated PLM (PKC mediated) stimulate NKA activity, which appears to be due to an increase in the turnover number of the enzyme; (ii) phosphorylated PLM did not change the affinity of the pump for Na(+); and (iii) even after phosphorylation by PKC, PLM still remains associated with the α(2) isoform of NKA.

  8. The 5-hydroxytryptamine transporter is functional in human coronary artery smooth muscle cells proliferation and is regulated by Interleukin-1 beta

    PubMed Central

    Wang, Qing-Jie; Wang, Dong; Tang, Cheng-Chun

    2015-01-01

    Abnormal human coronary artery smooth muscle cells (hCASMCs) proliferation and migration are key factors in coronary artery restenosis after percutaneous coronary intervention. Platelets release 5-hydroxytryptamine (5-HT), which is a strong mitogen for pulmonary artery smooth muscle cells proliferation and migration. Here, we investigated the effects of 5-HT and role of 5-HT transporter (5-HTT) on hCASMCs proliferation and migration. The 5-HT (10-6-10-5 mol/l) significantly increased hCASMCs proliferation and migration, and these effects were inhibited by fluoxetine (10-5 mol/l) and citalopram (10-6 mol/l), two 5-HTT blocker. Overexpression in hCASMCs enhanced 5-HT induced cells proliferation and migration. The 5-HTT and interleukin-1 beta (IL-1β) expression were increased in rat balloon injury carotid arteries. Treatment with IL-1β (10 ng/ml, 3d) upregulates 5-HTT expression in hCASMCs and increased 5-HT induced currents in Human Embryonic Kidney 293-5-HTT cells. PMID:26221231

  9. Magnolol inhibits colonic motility through down-regulation of voltage-sensitive L-type Ca2+ channels of colonic smooth muscle cells in rats.

    PubMed

    Zhang, Man; Zang, Kai-Hong; Luo, Jia-Lie; Leung, Fung-Ping; Huang, Yu; Lin, Cheng-Yuan; Yang, Zhi-Jun; Lu, Ai-Ping; Tang, Xu-Dong; Xu, Hong-Xi; Sung, Joseph Jao-yiu; Bian, Zhao-Xiang

    2013-11-15

    This study aimed to investigate the effect of magnolol (5,5'-diallyl-2,2'-biphenyldiol) on contraction in distal colonic segments of rats and the underlying mechanisms. Colonic segments were mounted in organ baths for isometric force measurement. Whole-cell voltage-sensitive L-type Ca(2+) currents were recorded on isolated single colonic smooth muscle cells using patch-clamp technique. The spontaneous contractions and acetylcholine (ACh)- and Bay K 8644-induced contractions were inhibited by magnolol (3-100 μM). In the presence of Bay K8644 (100 nM), magnolol (10-100 μM) inhibited the contraction induced by 10 μM ACh. By contrast, tetrodotoxin (100 nM) and Nώ-nitro-L-arginine methyl ester (L-NAME 100 μM) did not change the inhibitory effect of magnolol (10 μM). In addition, magnolol (3-100 μM) inhibited the L-type Ca(2+) currents. The present results suggest that magnolol inhibits colonic smooth muscle contraction through downregulating L-type Ca(2+) channel activity.

  10. Smoothing error pitfalls

    NASA Astrophysics Data System (ADS)

    von Clarmann, T.

    2014-04-01

    The difference due to the content of a priori information between a constrained retrieval and the true atmospheric state is usually represented by the so-called smoothing error. In this paper it is shown that the concept of the smoothing error is questionable because it is not compliant with Gaussian error propagation. The reason for this is that the smoothing error does not represent the expected deviation of the retrieval from the true state but the expected deviation of the retrieval from the atmospheric state sampled on an arbitrary grid, which is itself a smoothed representation of the true state. The idea of a sufficiently fine sampling of this reference atmospheric state is untenable because atmospheric variability occurs on all scales, implying that there is no limit beyond which the sampling is fine enough. Even the idealization of infinitesimally fine sampling of the reference state does not help because the smoothing error is applied to quantities which are only defined in a statistical sense, which implies that a finite volume of sufficient spatial extent is needed to meaningfully talk about temperature or concentration. Smoothing differences, however, which play a role when measurements are compared, are still a useful quantity if the involved a priori covariance matrix has been evaluated on the comparison grid rather than resulting from interpolation. This is, because the undefined component of the smoothing error, which is the effect of smoothing implied by the finite grid on which the measurements are compared, cancels out when the difference is calculated.

  11. Leiomodin and tropomodulin in smooth muscle

    NASA Technical Reports Server (NTRS)

    Conley, C. A.

    2001-01-01

    Evidence is accumulating to suggest that actin filament remodeling is critical for smooth muscle contraction, which implicates actin filament ends as important sites for regulation of contraction. Tropomodulin (Tmod) and smooth muscle leiomodin (SM-Lmod) have been found in many tissues containing smooth muscle by protein immunoblot and immunofluorescence microscopy. Both proteins cofractionate with tropomyosin in the Triton-insoluble cytoskeleton of rabbit stomach smooth muscle and are solubilized by high salt. SM-Lmod binds muscle tropomyosin, a biochemical activity characteristic of Tmod proteins. SM-Lmod staining is present along the length of actin filaments in rat intestinal smooth muscle, while Tmod stains in a punctate pattern distinct from that of actin filaments or the dense body marker alpha-actinin. After smooth muscle is hypercontracted by treatment with 10 mM Ca(2+), both SM-Lmod and Tmod are found near alpha-actinin at the periphery of actin-rich contraction bands. These data suggest that SM-Lmod is a novel component of the smooth muscle actin cytoskeleton and, furthermore, that the pointed ends of actin filaments in smooth muscle may be capped by Tmod in localized clusters.

  12. Quantum State Smoothing

    NASA Astrophysics Data System (ADS)

    Guevara, Ivonne; Wiseman, Howard

    2015-10-01

    Smoothing is an estimation method whereby a classical state (probability distribution for classical variables) at a given time is conditioned on all-time (both earlier and later) observations. Here we define a smoothed quantum state for a partially monitored open quantum system, conditioned on an all-time monitoring-derived record. We calculate the smoothed distribution for a hypothetical unobserved record which, when added to the real record, would complete the monitoring, yielding a pure-state "quantum trajectory." Averaging the pure state over this smoothed distribution yields the (mixed) smoothed quantum state. We study how the choice of actual unraveling affects the purity increase over that of the conventional (filtered) state conditioned only on the past record.

  13. Quantum State Smoothing.

    PubMed

    Guevara, Ivonne; Wiseman, Howard

    2015-10-30

    Smoothing is an estimation method whereby a classical state (probability distribution for classical variables) at a given time is conditioned on all-time (both earlier and later) observations. Here we define a smoothed quantum state for a partially monitored open quantum system, conditioned on an all-time monitoring-derived record. We calculate the smoothed distribution for a hypothetical unobserved record which, when added to the real record, would complete the monitoring, yielding a pure-state "quantum trajectory." Averaging the pure state over this smoothed distribution yields the (mixed) smoothed quantum state. We study how the choice of actual unraveling affects the purity increase over that of the conventional (filtered) state conditioned only on the past record.

  14. Diamond Smoothing Tools

    NASA Technical Reports Server (NTRS)

    Voronov, Oleg

    2007-01-01

    Diamond smoothing tools have been proposed for use in conjunction with diamond cutting tools that are used in many finish-machining operations. Diamond machining (including finishing) is often used, for example, in fabrication of precise metal mirrors. A diamond smoothing tool according to the proposal would have a smooth spherical surface. For a given finish machining operation, the smoothing tool would be mounted next to the cutting tool. The smoothing tool would slide on the machined surface left behind by the cutting tool, plastically deforming the surface material and thereby reducing the roughness of the surface, closing microcracks and otherwise generally reducing or eliminating microscopic surface and subsurface defects, and increasing the microhardness of the surface layer. It has been estimated that if smoothing tools of this type were used in conjunction with cutting tools on sufficiently precise lathes, it would be possible to reduce the roughness of machined surfaces to as little as 3 nm. A tool according to the proposal would consist of a smoothing insert in a metal holder. The smoothing insert would be made from a diamond/metal functionally graded composite rod preform, which, in turn, would be made by sintering together a bulk single-crystal or polycrystalline diamond, a diamond powder, and a metallic alloy at high pressure. To form the spherical smoothing tip, the diamond end of the preform would be subjected to flat grinding, conical grinding, spherical grinding using diamond wheels, and finally spherical polishing and/or buffing using diamond powders. If the diamond were a single crystal, then it would be crystallographically oriented, relative to the machining motion, to minimize its wear and maximize its hardness. Spherically polished diamonds could also be useful for purposes other than smoothing in finish machining: They would likely also be suitable for use as heat-resistant, wear-resistant, unlubricated sliding-fit bearing inserts.

  15. Vascular smooth muscle phenotypic diversity and function

    PubMed Central

    2010-01-01

    The control of force production in vascular smooth muscle is critical to the normal regulation of blood flow and pressure, and altered regulation is common to diseases such as hypertension, heart failure, and ischemia. A great deal has been learned about imbalances in vasoconstrictor and vasodilator signals, e.g., angiotensin, endothelin, norepinephrine, and nitric oxide, that regulate vascular tone in normal and disease contexts. In contrast there has been limited study of how the phenotypic state of the vascular smooth muscle cell may influence the contractile response to these signaling pathways dependent upon the developmental, tissue-specific (vascular bed) or disease context. Smooth, skeletal, and cardiac muscle lineages are traditionally classified into fast or slow sublineages based on rates of contraction and relaxation, recognizing that this simple dichotomy vastly underrepresents muscle phenotypic diversity. A great deal has been learned about developmental specification of the striated muscle sublineages and their phenotypic interconversions in the mature animal under the control of mechanical load, neural input, and hormones. In contrast there has been relatively limited study of smooth muscle contractile phenotypic diversity. This is surprising given the number of diseases in which smooth muscle contractile dysfunction plays a key role. This review focuses on smooth muscle contractile phenotypic diversity in the vascular system, how it is generated, and how it may determine vascular function in developmental and disease contexts. PMID:20736412

  16. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth muscle cell survival patterns to promote pulmonary arterial hypertension.

    PubMed

    Aghamohammadzadeh, Reza; Zhang, Ying-Yi; Stephens, Thomas E; Arons, Elena; Zaman, Paula; Polach, Kevin J; Matar, Majed; Yung, Lai-Ming; Yu, Paul B; Bowman, Frederick P; Opotowsky, Alexander R; Waxman, Aaron B; Loscalzo, Joseph; Leopold, Jane A; Maron, Bradley A

    2016-07-01

    Activation of the mammalian target of rapamycin complex 1 (mTORC1) subunit Raptor induces cell growth and is a downstream target of Akt. Elevated levels of aldosterone activate Akt, and, in pulmonary arterial hypertension (PAH), correlate with pulmonary arteriole thickening, which suggests that mTORC1 regulation by aldosterone may mediate adverse pulmonary vascular remodeling. We hypothesized that aldosterone-Raptor signaling induces abnormal pulmonary artery smooth muscle cell (PASMC) survival patterns to promote PAH. Remodeled pulmonary arterioles from SU-5416/hypoxia-PAH rats and monocrotaline-PAH rats with hyperaldosteronism expressed increased levels of the Raptor target, p70S6K, which provided a basis for investigating aldosterone-Raptor signaling in human PASMCs. Aldosterone (10(-9) to 10(-7) M) increased Akt/mTOR/Raptor to activate p70S6K and increase proliferation, viability, and apoptosis resistance in PASMCs. In PASMCs transfected with Raptor-small interfering RNA or treated with spironolactone/eplerenone, aldosterone or pulmonary arterial plasma from patients with PAH failed to increase p70S6K activation or to induce cell survival in vitro Optimal inhibition of pulmonary arteriole Raptor was achieved by treatment with Staramine-monomethoxy polyethylene glycol that was formulated with Raptor-small interfering RNA plus spironolactone in vivo, which decreased arteriole muscularization and pulmonary hypertension in 2 experimental animal models of PAH in vivo Up-regulation of mTORC1 by aldosterone is a critical pathobiologic mechanism that controls PASMC survival to promote hypertrophic vascular remodeling and PAH.-Aghamohammadzadeh, R., Zhang, Y.-Y., Stephens, T. E., Arons, E., Zaman, P., Polach, K. J., Matar, M., Yung, L.-M., Yu, P. B., Bowman, F. P., Opotowsky, A. R., Waxman, A. B., Loscalzo, J., Leopold, J. A., Maron, B. A. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth

  17. Molecular cloning, expression of, and regulation by thyroid-hormone receptor α A in the half-smooth tongue sole Cynoglossus semilaevis during metamorphosis.

    PubMed

    Zhang, W T; Liu, K; Xiang, J S; Zhang, L Y; Liu, W J; Dong, Z D; Li, Y Z; Li, H L; Chen, S L; Wang, N

    2016-05-01

    To elucidate the effect of thyroid hormone receptor α A (thraa) on metamorphosis, the full length cDNA of half-smooth tongue sole Cynoglossus semilaevis was cloned. The relative gene transcript level of thraa at different development stages was quantified using real-time PCR. Transcription of thraa increased and declined rapidly during metamorphosis. Hyperthyroidism was induced in juveniles and larvae with exposure to T3 and T4, and hypothyroidism with thiourea (TU), 2-mercapto-1-methylimidazole (MMI). thraa mRNA was higher in fish treated for 6 days with MMI than in untreated controls, although inhibited larvae did not complete metamorphosis. The addition of exogenous T4 reversed this effect in the MMI-treated group, but not in the TU-treated group. In situ hybridization revealed progressive tail end of body growth and change during developmental stages, with corresponding changes in thraa expression. This process may be induced by thyroid hormones with thraa as a major mediator. The morphological changes of tip of the tail may be associated with the development of lateral swimming.

  18. PPAR{gamma} activation abolishes LDL-induced proliferation of human aortic smooth muscle cells via SOD-mediated down-regulation of superoxide

    SciTech Connect

    Heo, Kyung-Sun; Kim, Dong-Uk; Ryoo, Sungwoo; Nam, Miyoung; Baek, Seung Tae; Kim, Lila; Park, Song-Kyu; Myung, Chang-Seon; Hoe, Kwang-Lae . E-mail: kwanghoe@kribb.re.kr

    2007-08-10

    Native LDL would be a mitogenic and chemotactic stimulus of VSMC proliferation and differentiation in the atherosclerotic lesion where endothelial disruption occurred. In previous studies, our group investigated the molecular mechanisms by which LDL induces IL-8 production and by which PPAR{alpha} activation abolishes LDL effects in human aortic SMCs (hAoSMCs). Herein is the first report of PPAR{gamma} activation by troglitazone (TG) exerting its inhibitory effects on LDL-induced cell proliferation via generation not of H{sub 2}O{sub 2}, but of O2?-, and the subsequent activation of Erk1/2 in hAoSMCs. Moreover, in this study TG abolished the LDL-accelerated G{sub 1}-S progression to control levels via down-regulation of active cyclinD1/CDK4 and cyclinE/CDK2 complexes and up-regulation of p21{sup Cip1} expression. TG exerted its anti-proliferative effects through the up-regulation of basal superoxide dismutase (SOD) expression. This data suggests that the regulation of O2?- is located at the crossroads between LDL signaling and cell proliferation.

  19. The inhibitory effect of dexamethasone on platelet-derived growth factor-induced vascular smooth muscle cell migration through up-regulating PGC-1{alpha} expression

    SciTech Connect

    Xu, Wei; Guo, Ting; Zhang, Yan; Jiang, Xiaohong; Zhang, Yongxian; Zen, Ke; Yu, Bo; Zhang, Chen-Yu

    2011-05-01

    Dexamethasone has been shown to inhibit vascular smooth muscle cell (VSMC) migration, which is required for preventing restenosis. However, the mechanism underlying effect of dexamethasone remains unknown. We have previously demonstrated that peroxisome proliferator-activated receptor gamma (PPAR{gamma}) coactivator-1 alpha (PGC-1{alpha}) can inhibit VSMC migration and proliferation. Here, we investigated the role of PGC-1{alpha} in dexamethasone-reduced VSMC migration and explored the possible mechanism. We first examined PGC-1{alpha} expression in cultured rat aortic VSMCs. The results revealed that incubation of VSMCs with dexamethasone could significantly elevate PGC-1{alpha} mRNA expression. In contrast, platelet-derived growth factor (PDGF) decreased PGC-1{alpha} expression while stimulating VSMC migration. Mechanistic study showed that suppression of PGC-1{alpha} by small interfering RNA strongly abrogated the inhibitory effect of dexamethasone on VSMC migration, whereas overexpression of PGC-1{alpha} had the opposite effect. Furthermore, an analysis of MAPK signal pathways showed that dexamethasone inhibited ERK and p38 MAPK phosphorylation in VSMCs. Overexpression of PGC-1{alpha} decreased both basal and PDGF-induced p38 MAPK phosphorylation, but it had no effect on ERK phosphorylation. Finally, inhibition of PPAR{gamma} activation by a PPAR{gamma} antagonist GW9662 abolished the suppressive effects of PGC-1{alpha} on p38 MAPK phosphorylation and VSMC migration. These effects of PGC-1{alpha} were enhanced by a PPAR{gamma} agonist troglitazone. Collectively, our data indicated for the first time that one of the anti-migrated mechanisms of dexamethasone is due to the induction of PGC-1{alpha} expression. PGC-1{alpha} suppresses PDGF-induced VSMC migration through PPAR{gamma} coactivation and, consequently, p38 MAPK inhibition.

  20. Gingipains from the Periodontal Pathogen Porphyromonas gingivalis Play a Significant Role in Regulation of Angiopoietin 1 and Angiopoietin 2 in Human Aortic Smooth Muscle Cells

    PubMed Central

    Khalaf, Hazem; Sirsjö, Allan; Bengtsson, Torbjörn

    2015-01-01

    Angiopoietin 1 (Angpt1) and angiopoietin 2 (Angpt2) are the ligands of tyrosine kinase (Tie) receptors, and they play important roles in vessel formation and the development of inflammatory diseases, such as atherosclerosis. Porphyromonas gingivalis is a Gram-negative periodontal bacterium that is thought to contribute to the progression of cardiovascular disease. The aim of this study was to investigate the role of P. gingivalis infection in the modulation of Angpt1 and Angpt2 in human aortic smooth muscle cells (AoSMCs). We exposed AoSMCs to wild-type (W50 and 381), gingipain mutant (E8 and K1A), and fimbrial mutant (DPG-3 and KRX-178) P. gingivalis strains and to different concentrations of tumor necrosis factor (TNF). The atherosclerosis risk factor TNF was used as a positive control in this study. We found that P. gingivalis (wild type, K1A, DPG3, and KRX178) and TNF upregulated the expression of Angpt2 and its transcription factor ETS1, respectively, in AoSMCs. In contrast, Angpt1 was inhibited by P. gingivalis and TNF. However, the RgpAB mutant E8 had no effect on the expression of Angpt1, Angpt2, or ETS1 in AoSMCs. The results also showed that ETS1 is critical for P. gingivalis induction of Angpt2. Exposure to Angpt2 protein enhanced the migration of AoSMCs but had no effect on proliferation. This study demonstrates that gingipains are crucial to the ability of P. gingivalis to markedly increase the expressed Angpt2/Angpt1 ratio in AoSMCs, which determines the regulatory role of angiopoietins in angiogenesis and their involvement in the development of atherosclerosis. These findings further support the association between periodontitis and cardiovascular disease. PMID:26283334

  1. Regulation of renal artery smooth muscle tone by alpha1-adrenoceptors: role of voltage-gated calcium channels and intracellular calcium stores.

    PubMed

    Eckert, R E; Karsten, A J; Utz, J; Ziegler, M

    2000-04-01

    The ischemia induced vasospasm of the renal arterial blood vessels mediated by alpha1-adrenoceptors is of importance for the loss of kidney function. This is based on reduced perfusion of the kidney cortex occurring in kidney transplant and organ preserving surgery. The present study considered the intracellular mechanism of the norepinephrine (NE) induced renal artery vasospasm by using swine renal artery smooth muscle ring. Norepinephrine and phenylephrine (PE) induced dose-dependent and fully reversible isometric contractions with a threshold concentration of 10 nM (n = 7) and 10 nM (n = 4), and an EC50 of 0.3 microM and 1 microM, respectively. The receptor was identified as alpha1A-subtype. The contraction was completely inhibited by verapamil (IC50 = 1.51 microM; n = 11) and diltiazem (IC50 = 9.49 microM; n = 8) and 85% by nifedipine (IC50 = 0.13 microM; n = 21). Blockade of the intracellular inositol- 1,4,5-trisphosphate (IP3)-sensitive Ca2+ store by thapsigargin (1 microM, n = 7) or suppression of Ca2+ release from the intracellular Ca2+-sensitive Ca2+ store by ryanodine (100 microM, n = 4) inhibited the PE induced contraction by 39.5% and 47.6%, respectively. The results suggest a key role of voltage-dependent Ca2+ channels and intracellular Ca2+ stores in the alpha1A-adrenoceptor induced contraction of the renal artery.

  2. BK channel-mediated relaxation of urinary bladder smooth muscle: a novel paradigm for phosphodiesterase type 4 regulation of bladder function.

    PubMed

    Xin, Wenkuan; Li, Ning; Cheng, Qiuping; Petkov, Georgi V

    2014-04-01

    Elevation of intracellular cAMP and activation of protein kinase A (PKA) lead to activation of large conductance voltage- and Ca(2+)-activated K(+) (BK) channels, thus attenuation of detrusor smooth muscle (DSM) contractility. In this study, we investigated the mechanism by which pharmacological inhibition of cAMP-specific phosphodiesterase 4 (PDE4) with rolipram or Ro-20-1724 (C(15)H(22)N(2)O(3)) suppresses guinea pig DSM excitability and contractility. We used high-speed line-scanning confocal microscopy, ratiometric fluorescence Ca(2+) imaging, and perforated whole-cell patch-clamp techniques on freshly isolated DSM cells, along with isometric tension recordings of DSM isolated strips. Rolipram caused an increase in the frequency of Ca(2+) sparks and the spontaneous transient BK currents (TBKCs), hyperpolarized the cell membrane potential (MP), and decreased the intracellular Ca(2+) levels. Blocking BK channels with paxilline reversed the hyperpolarizing effect of rolipram and depolarized the MP back to the control levels. In the presence of H-89 [N-[2-[[3-(4-bromophenyl)-2-propenyl]amino]ethyl]-5-isoquinolinesulfonamide dihydrochloride], a PKA inhibitor, rolipram did not cause MP hyperpolarization. Rolipram or Ro-20-1724 reduced DSM spontaneous and carbachol-induced phasic contraction amplitude, muscle force, duration, and frequency, and electrical field stimulation-induced contraction amplitude, muscle force, and tone. Paxilline recovered DSM contractility, which was suppressed by pretreatment with PDE4 inhibitors. Rolipram had reduced inhibitory effects on DSM contractility in DSM strips pretreated with paxilline. This study revealed a novel cellular mechanism whereby pharmacological inhibition of PDE4 leads to suppression of guinea pig DSM contractility by increasing the frequency of Ca(2+) sparks and the functionally coupled TBKCs, consequently hyperpolarizing DSM cell MP. Collectively, this decreases the global intracellular Ca(2+) levels and DSM

  3. Ras/ERK1 pathway regulation of p27KIP1-mediated G1-phase cell-cycle arrest in cordycepin-induced inhibition of the proliferation of vascular smooth muscle cells.

    PubMed

    Jung, Su-Mi; Park, Sung-Soo; Kim, Wun-Jae; Moon, Sung-Kwon

    2012-04-15

    Cordycepin, the main constituent of Cordyceps militaris, demonstrated an anti-atherogenic effect in experimental animals. However, the effects of cordycepin on cell-cycle regulation and the signaling pathway in vascular smooth muscle cells (VSMC) remain largely unknown; therefore, unexpected roles of cordycepin-induced inhibition in VSMC growth were investigated. Mechanisms in cordycepin-treated VSMC were examined via an MTT assay, a thymidine uptake experiment, FACS analysis, immunoblot analysis, kinase assay, immunoprecipitation assay, and transient transfection assays. Cordycepin inhibited cell growth, induced G1-phase cell-cycle arrest, down-regulated cyclins and cyclin-dependent kinase (CDK) expression, and up-regulated p27KIP1 expression in VSMC. Cordycepin induced activation of JNK, p38MAPK and ERK1/2. Blocking of the ERK function using either ERK1/2-specific inhibitor U0126 or a small interfering RNA (si-ERK1) reversed p27KIP1 expression, inhibition of cell growth, and decreased cell-cycle proteins in cordycepin-treated VSMC. Ras activation was increased by cordycepin. Transfection of cells with dominant negative Ras (RasN17) mutant genes rescued cordycepin-induced ERK1/2 activity, increased p27KIP1 expression, inhibited cell proliferation, and reduced cell cycle proteins. In conclusion, our findings indicate that Ras/ERK1 pathways participate in p27KIP1-mediated G1-phase cell-cycle arrest induced by cordycepin via a decrease in cyclin/CDK complexes in VSMC.

  4. Decreased microRNA-143 expression and its tumor suppressive function in human oral squamous cell carcinoma.

    PubMed

    Ni, Z Y; Lin, F O; Liu, D F; Xiao, J

    2015-06-26

    MicroRNA-143 serves as a tumor suppressor in many human malignancies. However, its involvement in oral squamous cell carcinoma (OSCC) is still unclear. In this study, we investigated the effects of miR-143 in OSCC tumorigenesis and development. Using real-time quantitative reverse transcription-polymerase chain reaction, we detected miR-143 expression in 109 pairs of human OSCC and adjacent noncancerous tissues. The associations between miR-143 expression and clinicopathological factors and prognosis of OSCC patients were also statistically analyzed. Further, the effects of miR-143 on the biological behavior of OSCC cells were investigated. miR-143 expression was significantly downregulated in OSCC tissue samples and cell lines. Decreased miR-143 expression was significantly associated with advanced T classifications, positive N classification, advanced TNM stage, and shorter overall survival. In addition, upregulation of miR-143 in Tca8113 cells reduced cell proliferation, invasion, and migration, as well as promoted cell apoptosis in vitro. These findings validate the clinical significance of miR-143 in OSCC and reveal that it may be an intrinsic regulator of tumor progression and a potential prognostic factor for this disease.

  5. Smoothing error pitfalls

    NASA Astrophysics Data System (ADS)

    von Clarmann, T.

    2014-09-01

    The difference due to the content of a priori information between a constrained retrieval and the true atmospheric state is usually represented by a diagnostic quantity called smoothing error. In this paper it is shown that, regardless of the usefulness of the smoothing error as a diagnostic tool in its own right, the concept of the smoothing error as a component of the retrieval error budget is questionable because it is not compliant with Gaussian error propagation. The reason for this is that the smoothing error does not represent the expected deviation of the retrieval from the true state but the expected deviation of the retrieval from the atmospheric state sampled on an arbitrary grid, which is itself a smoothed representation of the true state; in other words, to characterize the full loss of information with respect to the true atmosphere, the effect of the representation of the atmospheric state on a finite grid also needs to be considered. The idea of a sufficiently fine sampling of this reference atmospheric state is problematic because atmospheric variability occurs on all scales, implying that there is no limit beyond which the sampling is fine enough. Even the idealization of infinitesimally fine sampling of the reference state does not help, because the smoothing error is applied to quantities which are only defined in a statistical sense, which implies that a finite volume of sufficient spatial extent is needed to meaningfully discuss temperature or concentration. Smoothing differences, however, which play a role when measurements are compared, are still a useful quantity if the covariance matrix involved has been evaluated on the comparison grid rather than resulting from interpolation and if the averaging kernel matrices have been evaluated on a grid fine enough to capture all atmospheric variations that the instruments are sensitive to. This is, under the assumptions stated, because the undefined component of the smoothing error, which is the

  6. Mechanics of Vascular Smooth Muscle.

    PubMed

    Ratz, Paul H

    2015-12-15

    Vascular smooth muscle (VSM; see Table 1 for a list of abbreviations) is a heterogeneous biomaterial comprised of cells and extracellular matrix. By surrounding tubes of endothelial cells, VSM forms a regulated network, the vasculature, through which oxygenated blood supplies specialized organs, permitting the development of large multicellular organisms. VSM cells, the engine of the vasculature, house a set of regulated nanomotors that permit rapid stress-development, sustained stress-maintenance and vessel constriction. Viscoelastic materials within, surrounding and attached to VSM cells, comprised largely of polymeric proteins with complex mechanical characteristics, assist the engine with countering loads imposed by the heart pump, and with control of relengthening after constriction. The complexity of this smart material can be reduced by classical mechanical studies combined with circuit modeling using spring and dashpot elements. Evaluation of the mechanical characteristics of VSM requires a more complete understanding of the mechanics and regulation of its biochemical parts, and ultimately, an understanding of how these parts work together to form the machinery of the vascular tree. Current molecular studies provide detailed mechanical data about single polymeric molecules, revealing viscoelasticity and plasticity at the protein domain level, the unique biological slip-catch bond, and a regulated two-step actomyosin power stroke. At the tissue level, new insight into acutely dynamic stress-strain behavior reveals smooth muscle to exhibit adaptive plasticity. At its core, physiology aims to describe the complex interactions of molecular systems, clarifying structure-function relationships and regulation of biological machines. The intent of this review is to provide a comprehensive presentation of one biomachine, VSM.

  7. Simvastatin attenuates the additive effects of TNF-α and IL-18 on the connexin 43 up-regulation and over-proliferation of cultured aortic smooth muscle cells.

    PubMed

    Lin, Yu-Chun; Chiang, Chiang-Hua; Chang, Li-Teh; Sun, Cheuk-Kwan; Leu, Steve; Shao, Pei-Lin; Hsieh, Ming-Chu; Tsai, Tzu-Hsien; Chua, Sarah; Chung, Sheng-Ying; Kao, Ying-Hsien; Yip, Hon-Kan

    2013-06-01

    Statin therapy is known to down-regulate inflammatory activities in atheromatous tissues of animals. The aims of this study were to examine the regulatory role of interleukin-18 (IL-18) in the connexin 43 (Cx43) and the proliferation of cultured aortic smooth muscle cells (SMCs) as well as to elucidate the underlying therapeutic mechanism of simvastatin. Vytorin therapy significantly alleviated high-cholesterol diet-induced hypercholesterolemia, suppressed neointimal hyperplasia, macrophage infiltration, and Cx43 and IL-18 expression in rabbit aortic walls. In vitro study using an aortic SMC line showed that IL-18 up-regulated constitutive Cx43 expression and potentiated tumor necrosis factor-α (TNF-α)-triggered Akt and MAPK signaling pathways. Simvastatin treatment alone reduced constitutive Cx43 levels and prevented the TNF-α-induced IL-18 up-regulation. Mechanistic investigation using kinase-specific inhibitors showed that simvastatin pretreatment attenuated TNF-α-elicited Akt and ERK1/2 phosphorylation, whereas PI3K and all MAPK activities were also implied in the additive effect of TNF-α and IL-18 on Cx43 up-regulation. Proliferation assay indicated that IL-18 stimulated SMC proliferation and synergized the TNF-α-stimulated cell proliferation. Likewise, simvastatin treatment suppressed the SMC over-proliferation induced not only by TNF-α alone, but also by simultaneous treatment with TNF-α and IL-18. The suppression of simvastatin in SMC proliferation was not mediated through mitochondrial related pro-apoptogenesis under both scenarios. In conclusion, simvastatin attenuates the additive effects of TNF-α and IL-18 on Cx43 up-regulation and over-proliferation of aortic SMCs, mainly through the blockade of Akt signaling pathway. These findings may fortify the rationale underlying the atheroprotective mechanism of statin therapy.

  8. Arginase II is a target of miR-17-5p and regulates miR-17-5p expression in human pulmonary artery smooth muscle cells.

    PubMed

    Jin, Youpeng; Jin, Yi; Chen, Bernadette; Tipple, Trent E; Nelin, Leif D

    2014-07-15

    Vascular remodeling and smooth muscle cell proliferation are hallmark pathogenic features of pulmonary artery hypertension. MicroRNAs, endogenously expressed small noncoding RNAs, regulate gene expression at the posttranscriptional level. It has previously been shown that miR-17 overexpression in cultured human pulmonary artery smooth muscle cell (hPASMC) resulted in increased viable cell number. Previously, we have found that arginase II promotes hypoxia-induced proliferation in hPASMC. Therefore, we hypothesized that miR-17 would be upregulated by hypoxia in hPASMC and would result in greater arginase II expression. We found that levels of miR-17-5p and arginase II were significantly greater in cultured hPASMC exposed to 1% O2 for 48 h than in hPASMC exposed to 21% O2 for 48 h. Furthermore, inhibiting miR-17-5p expression decreased hypoxia-induced arginase II protein levels in hPASMC. Conversely, overexpressing miR-17-5p resulted in greater arginase II protein levels. Somewhat surprisingly, arginase II inhibition was associated with lower miR-17-5p expression in both normoxic and hypoxic hPASMC, whereas overexpressing arginase II resulted in greater miR-17-5p expression in hPASMC. These findings suggest that hypoxia-induced arginase II expression is not only regulated by miR-17-5p but also that there is a feedback loop between arginase II and miR-17-5p in hPASMC. We also found that the arginase II-mediated regulation of miR-17-5p was independent of either p53 or c-myc. We also found that l-arginine, the substrate for arginase II, and l-ornithine, the amino acid product of arginase II, were not involved in the regulation of miR-17-5p expression.

  9. Mechanisms of Vascular Smooth Muscle Contraction and the Basis for Pharmacologic Treatment of Smooth Muscle Disorders

    PubMed Central

    Brozovich, F.V.; Nicholson, C.J.; Degen, C.V.; Gao, Yuan Z.; Aggarwal, M.

    2016-01-01

    The smooth muscle cell directly drives the contraction of the vascular wall and hence regulates the size of the blood vessel lumen. We review here the current understanding of the molecular mechanisms by which agonists, therapeutics, and diseases regulate contractility of the vascular smooth muscle cell and we place this within the context of whole body function. We also discuss the implications for personalized medicine and highlight specific potential target molecules that may provide opportunities for the future development of new therapeutics to regulate vascular function. PMID:27037223

  10. A Novel CaV1.2 N Terminus Expressed in Smooth Muscle Cells of Resistance Size Arteries Modifies Channel Regulation by Auxiliary Subunits*S

    PubMed Central

    Cheng, Xiaoyang; Liu, Jianxi; Asuncion-Chin, Maria; Blaskova, Eva; Bannister, John P.; Dopico, Alejandro M.; Jaggar, Jonathan H.

    2008-01-01

    Voltage-dependent L-type Ca2+ (CaV1.2) channels are the principal Ca2+ entry pathway in arterial myocytes. CaV1.2 channels regulate multiple vascular functions and are implicated in the pathogenesis of human disease, including hypertension. However, the molecular identity of CaV1.2 channels expressed in myocytes of myogenic arteries that regulate vascular pressure and blood flow is unknown. Here, we cloned CaV1.2 subunits from resistance size cerebral arteries and demonstrate that myocytes contain a novel, cysteine rich N terminus that is derived from exon 1 (termed “exon 1c”), which is located within CACNA1C, the CaV1.2 gene. Quantitative PCR revealed that exon 1c was predominant in arterial myocytes, but rare in cardiac myocytes, where exon 1a prevailed. When co-expressed with α2δ subunits, CaV1.2 channels containing the novel exon 1c-derived N terminus exhibited: 1) smaller whole cell current density, 2) more negative voltages of half activation (V1/2,act) and half-inactivation (V1/2,inact), and 3) reduced plasma membrane insertion, when compared with channels containing exon 1b. β1b and β2a subunits caused negative shifts in the V1/2,act and V1/2,inact of exon 1b-containing CaV1.2α1/α2δ currents that were larger than those in exon 1c-containing CaV1.2α1/α2δ currents. In contrast, β3 similarly shifted V1/2,act and V1/2,inact of currents generated by exon 1b- and exon 1c-containing channels. β subunits isoform-dependent differences in current inactivation rates were also detected between N-terminal variants. Data indicate that through novel alternative splicing at exon 1, the CaV1.2 N terminus modifies regulation by auxiliary subunits. The novel exon 1c should generate distinct voltage-dependent Ca2+ entry in arterial myocytes, resulting in tissue-specific Ca2+ signaling. PMID:17699517

  11. Smooth muscle actin and myosin expression in cultured airway smooth muscle cells.

    PubMed

    Wong, J Z; Woodcock-Mitchell, J; Mitchell, J; Rippetoe, P; White, S; Absher, M; Baldor, L; Evans, J; McHugh, K M; Low, R B

    1998-05-01

    In this study, the expression of smooth muscle actin and myosin was examined in cultures of rat tracheal smooth muscle cells. Protein and mRNA analyses demonstrated that these cells express alpha- and gamma-smooth muscle actin and smooth muscle myosin and nonmuscle myosin-B heavy chains. The expression of the smooth muscle specific actin and myosin isoforms was regulated in the same direction when growth conditions were changed. Thus, at confluency in 1 or 10% serum-containing medium as well as for low-density cells (50-60% confluent) deprived of serum, the expression of the smooth muscle forms of actin and myosin was relatively high. Conversely, in rapidly proliferating cultures at low density in 10% serum, smooth muscle contractile protein expression was low. The expression of nonmuscle myosin-B mRNA and protein was more stable and was upregulated only to a small degree in growing cells. Our results provide new insight into the molecular basis of differentiation and contractile function in airway smooth muscle cells.

  12. The sGC activator inhibits the proliferation and migration, promotes the apoptosis of human pulmonary arterial smooth muscle cells via the up regulation of plasminogen activator inhibitor-2

    SciTech Connect

    Zhang, Shuai; Zou, Lihui; Yang, Ting; Yang, Yuanhua; Zhai, Zhenguo; Xiao, Fei; Wang, Chen

    2015-03-15

    Background: Different types of pulmonary hypertension (PH) share the same process of pulmonary vascular remodeling, the molecular mechanism of which is not entirely clarified by far. The abnormal biological behaviors of pulmonary arterial smooth muscle cells (PASMCs) play an important role in this process. Objectives: We investigated the regulation of plasminogen activator inhibitor-2 (PAI-2) by the sGC activator, and explored the effect of PAI-2 on PASMCs proliferation, apoptosis and migration. Methods: After the transfection with PAI-2 overexpression vector and specific siRNAs or treatment with BAY 41-2272 (an activator of sGC), the mRNA and protein levels of PAI-2 in cultured human PASMCs were detected, and the proliferation, apoptosis and migration of PASMCs were investigated. Results: BAY 41-2272 up regulated the endogenous PAI-2 in PASMCs, on the mRNA and protein level. In PAI-2 overexpression group, the proliferation and migration of PASMCs were inhibited significantly, and the apoptosis of PASMCs was increased. In contrast, PAI-2 knockdown with siRNA increased PASMCs proliferation and migration, inhibited the apoptosis. Conclusions: PAI-2 overexpression inhibits the proliferation and migration and promotes the apoptosis of human PASMCs. Therefore, sGC activator might alleviate or reverse vascular remodeling in PH through the up-regulation of PAI-2. - Highlights: • sGC activator BAY41-2272 up regulated PAI-2 in PASMCs, on the mRNA and protein level. • PAI-2 overexpression inhibits the proliferation and migration of human PASMCs. • PAI-2 overexpression promotes the apoptosis of human PASMCs. • sGC activator might alleviate the vascular remodeling in pulmonary hypertension.

  13. Smoothly deformed light

    NASA Technical Reports Server (NTRS)

    Stenholm, Stig

    1993-01-01

    A single mode cavity is deformed smoothly to change its electromagnetic eigenfrequency. The system is modeled as a simple harmonic oscillator with a varying period. The Wigner function of the problem is obtained exactly by starting with a squeezed initial state. The result is evaluated for a linear change of the cavity length. The approach to the adiabatic limit is investigated. The maximum squeezing is found to occur for smooth change lasting only a fraction of the oscillational period. However, only a factor of two improvement over the adiabatic result proves to be possible. The sudden limit cannot be investigated meaningfully within the model.

  14. [Involvement of the receptor component protein in the regulation of vascular peroxidase-1 expression induced by calcitonin gene-related peptide and angiotensin II in vascular smooth muscle cell].

    PubMed

    Liu, Yan-Mei; Peng, Hong-Yan; Guo, Feng; Quan, Hai-Yan; Luo, Jing-Fei; Qin, Xu-Ping

    2015-04-25

    Angiotensin II (Ang II) and calcitonin gene-related peptide (CGRP) play important roles in vascular injury and protection. In order to determine the role of CGRP receptor component protein (RCP) in signal transduction whereby CGRP and Ang II mediate the expression of vascular peroxidase-1 (VPO1) in vascular smooth muscle cell (VSMC), mouse derived A10 vascular smooth muscle cell line (A10VSMC) was cultured with CGRP or/and Ang II in vitro. RCP-specific small interference RNA (siRNA-RCP) was used to silence oligonucleotide sequence. Western blot and RT-PCR were used to determine the protein and mRNA expressions of RCP and VPO1, respectively. The results showed that the expressions of RCP and VPO1 were increased in the presence of CGRP or Ang II in the quiescent A10VSMC. But the protein expressions of RCP and VPO1 induced by Ang II were decreased by pretreatment of CGRP (P < 0.05). The expressions of VPO1 were decreased in all the groups treated with siRNA-RCP, compared with those of wide-type counterparts. Meanwhile, the expression of VPO1 was significantly induced by CGRP but not Ang II in the siRNA-RCP treated A10VSMCs. Ang II in combination with CGRP increased the protein expression of VPO1 in the siRNA-RCP-transfected cells, compared with Ang II alone, and this effect could be abolished by catalase. The results suggest that RCP may play an important role in the integration of signal transduction whereby CGRP and Ang II receptors jointly regulate VPO1 expression in VSMC.

  15. Smoothed Particle Hydrodynamic Simulator

    SciTech Connect

    2016-10-05

    This code is a highly modular framework for developing smoothed particle hydrodynamic (SPH) simulations running on parallel platforms. The compartmentalization of the code allows for rapid development of new SPH applications and modifications of existing algorithms. The compartmentalization also allows changes in one part of the code used by many applications to instantly be made available to all applications.

  16. Some properties of caldesmon and calponin and the participation of these proteins in regulation of smooth muscle contraction and cytoskeleton formation.

    PubMed

    Gusev, N B

    2001-10-01

    The interaction of caldesmon with different Ca2+-binding proteins has been analyzed, and it is supposed that one of the conformers of calmodulin might be an endogenous regulator of caldesmon. The arrangement of caldesmon and Ca2+-binding proteins within their complexes has been analyzed by different methods. The central helix of calmodulin is supposed to be located near the single Cys residue in the C-terminal domain of caldesmon. The N-terminal globular domain of calmodulin interacts with sites A and B' of caldesmon, whereas the C-terminal globular domain of calmodulin binds to site B of caldesmon. The complex of calmodulin and caldesmon is very flexible; therefore, both parallel and antiparallel orientation of polypeptide chains of the two proteins is possible in experiments with short fragments of caldesmon and calmodulin. The length, flexibility, and charge of the central helix of calmodulin play an important role in its interaction with caldesmon. Phosphorylation of caldesmon by different protein kinases in vitro has been analyzed. It was shown that phosphorylation catalyzed by casein kinase II of sites located in the N-terminal domain decreases the interaction of caldesmon with myosin and tropomyosin. Caldesmon and calponin may interact with phospholipids. The sites involved in the interaction of these actin-binding proteins with phospholipids have been mapped. It is supposed that the interaction of calponin and caldesmon with phospholipids may play a role in the formation of cytoskeleton. Calponin interacts with 90-kD heat shock protein (hsp90) that may be involved in transportation of calponin and its proper interaction with different elements of cytoskeleton. Calponin, filamin, and alpha-actinin can simultaneously interact with actin filaments. Simultaneous binding of two actin-binding proteins affects the structure of actin bundles and their mechanical properties and may be of great importance in formation of different elements of cytoskeleton.

  17. A novel E1B55kDa-deleted oncolytic adenovirus carrying microRNA-143 exerts specific antitumor efficacy on colorectal cancer cells

    PubMed Central

    Luo, Qifeng; Basnet, Shiva; Dai, Zhenling; Li, Shuping; Zhang, Zhenyu; Ge, Haiyan

    2016-01-01

    The KRAS is an important and frequently mutated gene during colorectal carcinogenesis. The expression of miR-143 is often down-regulated and it might play an important role by targeting KRAS in colorectal cancer (CRC). The purpose of this study was to investigate the antitumor effects of miR-143 with an intermediate oncolytic adenovirus (Ad) in CRC. We constructed the recombinant virus Ad-ZD55-miR-143 and verified its expression by qPCR and western blot assays. Oncolytic potency of Ad-ZD55-miR-143 was determined by cytopathic effect assays using human SW480 CRC cells and L-02 normal liver cells. MTT and cell apoptosis assays were applied to explore the biological functions of Ad-ZD55-miR-143 within SW480 cells. Dual-luciferase reporter assays were performed to validate whether KRAS was regulated by miR-143. The expression level of KRAS was measured by qPCR and western blot assays. Results showed that infection of SW480 cells with Ad-ZD55-miR-143 induced high level expression of miR-143. Furthermore, Ad-ZD55-miR-143 significantly suppressed the viability of SW480 cells in a dose-dependent pattern, but did not influence L-02 cells. Ad-ZD55-miR-143 also inhibited cell growth and induced cell apoptosis in SW480 cells. Dual-luciferase assays indicated that KRAS was a direct target of miR-143, as subsequently demonstrated by qPCR and western blot analysis showing that infection of SW480 cells with Ad-ZD55-miR-143 resulted in the down-regulation of KRAS at both mRNA and protein levels. Taken together, the recombinant virus Ad-ZD55-miR-143 exhibited specific antitumor effects by targeting KRAS, and might be a promising agent for the treatment of CRC. PMID:27725862

  18. Icariin inhibits oxidized low-density lipoprotein-induced proliferation of vascular smooth muscle cells by suppressing activation of extracellular signal-regulated kinase 1/2 and expression of proliferating cell nuclear antigen.

    PubMed

    Hu, Yanwu; Liu, Kai; Yan, Mengtong; Zhang, Yang; Wang, Yadi; Ren, Liqun

    2016-03-01

    Icariin, a flavonoid isolated from the traditional Chinese herbal medicine Epimedium brevicornum Maxim, has been shown to possess anti-inflammatory, anti‑oxidant and anti-atherosclerotic activities in vivo and in vitro. The aim of the present study was to investigate the effects of icariin on oxidized low‑density lipoprotein (ox-LDL)-induced proliferation of vascular smooth muscle cells (VSMCs) and the possible underlying mechanism. VSMCs were cultured and pre‑treated with various concentrations of icariin (0, 10, 20 or 40 µm) prior to stimulation by ox‑LDL (50 µg/ml). Cell proliferation was evaluated by an MTT assay. Flow cytometry was used to study the influence of icariin on the cell cycle. Proliferating cell nuclear antigen (PCNA) expression and phosphorylation levels of extracellular signal-regulated kinase (ERK)1/2 were detected by western blot analysis. The results indicated that icariin significantly inhibited ox‑LDL‑induced proliferation of VSMCs and phosphorylation of ERK1/2. Furthermore, icariin also blocked the ox‑LDL‑induced cell‑cycle progression at G1/S‑interphase and downregulated the expression of PCNA in VSMCs. In conclusion, the present study indicated for the first time that icariin reduced the amount of ox‑LDL‑induced proliferation of VSMCs through suppression of PCNA expression and inactivation of ERK1/2.

  19. PKC-dependent extracellular signal-regulated kinase 1/2 pathway is involved in the inhibition of Ib on AngiotensinII-induced proliferation of vascular smooth muscle cells

    SciTech Connect

    Wang Yu; Yan Tianhua; Wang Qiujuan Wang Wei; Xu Jinyi; Wu Xiaoming; Ji Hui

    2008-10-10

    AngiotensinII (AngII) induces vascular smooth muscle cell (VSMC) proliferation, which plays an important role in the development and progression of hypertension. AngII-induced cellular events have been implicated, in part, in the activation of protein kinase C (PKC) and extracellular signal-regulated kinases 1/2 (ERK1/2). In the present study, we investigated the effect of Ib, a novel nonpeptide AngII receptor type 1 (AT{sub 1}) antagonist, on the activation of PKC and ERK1/2 in VSMC proliferation induced by AngII. MTT, and [{sup 3}H]thymidine incorporation assay showed that AngII-induced VSMC proliferation was inhibited significantly by Ib. The specific binding of [{sup 125}I]AngII to AT{sub 1} receptors was blocked by Ib in a concentration-dependent manner with IC{sub 50} value of 0.96 nM. PKC activity assay and Western blot analysis demonstrated that Ib significantly inhibited the activation of PKC and phosphorylation of ERK1/2 induced by AngII, respectively. Furthermore, AngII-induced ERK1/2 activation was obviously blocked by GF109203X, a PKC inhibitor. These findings suggest that the suppression of Ib on AngII-induced VSMC proliferation may be attributed to its inhibitory effect on PKC-dependent ERK1/2 pathway.

  20. Anti-smooth muscle antibody

    MedlinePlus

    ... gov/ency/article/003531.htm Anti-smooth muscle antibody To use the sharing features on this page, please enable JavaScript. Anti-smooth muscle antibody is a blood test that detects the presence ...

  1. Calcium Sensitization Mechanisms in Gastrointestinal Smooth Muscles.

    PubMed

    Perrino, Brian A

    2016-04-30

    An increase in intracellular Ca(2+) is the primary trigger of contraction of gastrointestinal (GI) smooth muscles. However, increasing the Ca(2+) sensitivity of the myofilaments by elevating myosin light chain phosphorylation also plays an essential role. Inhibiting myosin light chain phosphatase activity with protein kinase C-potentiated phosphatase inhibitor protein-17 kDa (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) phosphorylation is considered to be the primary mechanism underlying myofilament Ca(2+) sensitization. The relative importance of Ca(2+) sensitization mechanisms to the diverse patterns of GI motility is likely related to the varied functional roles of GI smooth muscles. Increases in CPI-17 and MYPT1 phosphorylation in response to agonist stimulation regulate myosin light chain phosphatase activity in phasic, tonic, and sphincteric GI smooth muscles. Recent evidence suggests that MYPT1 phosphorylation may also contribute to force generation by reorganization of the actin cytoskeleton. The mechanisms responsible for maintaining constitutive CPI-17 and MYPT1 phosphorylation in GI smooth muscles are still largely unknown. The characteristics of the cell-types comprising the neuroeffector junction lead to fundamental differences between the effects of exogenous agonists and endogenous neurotransmitters on Ca(2+) sensitization mechanisms. The contribution of various cell-types within the tunica muscularis to the motor responses of GI organs to neurotransmission must be considered when determining the mechanisms by which Ca(2+) sensitization pathways are activated. The signaling pathways regulating Ca(2+) sensitization may provide novel therapeutic strategies for controlling GI motility. This article will provide an overview of the current understanding of the biochemical basis for the regulation of Ca(2+) sensitization, while also discussing the functional importance to different smooth muscles of the GI tract.

  2. Inhibitory Effects of Hydrogen on Proliferation and Migration of Vascular Smooth Muscle Cells via Down-Regulation of Mitogen/Activated Protein Kinase and Ezrin-Radixin-Moesin Signaling Pathways.

    PubMed

    Zhang, Ya-Xing; Xu, Jing-Ting; You, Xin-Chao; Wang, Chen; Zhou, Ke-Wen; Li, Ping; Sun, Peng; Wang, Ling; Wang, Ting-Huai

    2016-02-29

    Molecular hydrogen (H₂) has recently attracted considerable attention for the prevention of oxidative stress-related vascular diseases. The purpose of this study is to evaluate the effects of hydrogen on proliferation and migration of vascular smooth muscle cells (VSMCs) stimulated by angiotensin II (Ang II) in vitro, and on vascular hypertrophy induced by abdominal aortic coarctation (AAC) in vivo. Hydrogen-rich medium (0.6~0.9 ppm) was added 30 min before 10⁻⁷ M Ang II administration, then the proliferation and migration index were determined 24 h after Ang II stimulation. Hydrogen gas (99.999%) was given by intraperitoneal injection at the dose of 1 ml/100 g/day consecutively for one week before AAC and lasted for 6 weeks in vivo. Hydrogen inhibited proliferation and migration of VSMCs with Ang II stimulation in vitro, and improved the vascular hypertrophy induced by AAC in vivo. Treatment with hydrogen reduced Ang II- or AAC-induced oxidative stress, which was reflected by diminishing the induction of reactive oxygen species (ROS) in Ang II-stimulated VSMCs, inhibiting the levels of 3-nitrotyrosine (3-NT) in vascular and serum malondialdehyde (MDA). Hydrogen treatment also blocked Ang II-induced phosphorylation of the extracellular signal-regulated kinase1/2 (ERK1/2), p38 MAPK, c-Jun NH₂-terminal kinase (JNK) and the ezrin/radixin/moesin (ERM) in vitro. Taken together, our studies indicate that hydrogen prevents AAC-induced vascular hypertrophy in vivo, and inhibits Ang II-induced proliferation and migration of VSMCs in vitro possibly by targeting ROS-dependent ERK1/2, p38 MAPK, JNK and ERM signaling. It provides the molecular basis of hydrogen on inhibiting the abnormal proliferation and migration of VSMCs and improving vascular remodeling diseases.

  3. MicroRNAs as regulators of metabolic disease: pathophysiologic significance and emerging role as biomarkers and therapeutics.

    PubMed

    Deiuliis, J A

    2016-01-01

    The prevalence of overweight and obesity in developed and developing countries has greatly increased the risk of insulin resistance and type 2 diabetes mellitus. It is evident from human and animal studies that obesity alters microRNA (miRNA) expression in metabolically important organs, and that miRNAs are involved in changes to normal physiology, acting as mediators of disease. miRNAs regulate multiple pathways including insulin signaling, immune-mediated inflammation, adipokine expression, adipogenesis, lipid metabolism, and food intake regulation. Thus, miRNA-based therapeutics represent an innovative and attractive treatment modality, with non-human primate studies showing great promise. In addition, miRNA measures in plasma or bodily fluids may be used as disease biomarkers and predictors of metabolic disease in humans. This review analyzes the role of miRNAs in obesity and insulin resistance, focusing on the miR-17/92, miR-143-145, miR-130, let-7, miR-221/222, miR-200, miR-223, miR-29 and miR-375 families, as well as miRNA changes by relevant tissue (adipose, liver and skeletal muscle). Further, the current and future applications of miRNA-based therapeutics and diagnostics in metabolic disease are discussed.

  4. Silencing microRNA-143 protects the integrity of the blood-brain barrier: implications for methamphetamine abuse

    PubMed Central

    Bai, Ying; Zhang, Yuan; Hua, Jun; Yang, Xiangyu; Zhang, Xiaotian; Duan, Ming; Zhu, Xinjian; Huang, Wenhui; Chao, Jie; Zhou, Rongbin; Hu, Gang; Yao, Honghong

    2016-01-01

    MicroRNA-143 (miR-143) plays a critical role in various cellular processes; however, the role of miR-143 in the maintenance of blood-brain barrier (BBB) integrity remains poorly defined. Silencing miR-143 in a genetic animal model or via an anti-miR-143 lentivirus prevented the BBB damage induced by methamphetamine. miR-143, which targets p53 unregulated modulator of apoptosis (PUMA), increased the permeability of human brain endothelial cells and concomitantly decreased the expression of tight junction proteins (TJPs). Silencing miR-143 increased the expression of TJPs and protected the BBB integrity against the effects of methamphetamine treatment. PUMA overexpression increased the TJP expression through a mechanism that involved the NF-κB and p53 transcription factor pathways. Mechanistically, methamphetamine mediated up-regulation of miR-143 via sigma-1 receptor with sequential activation of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3′ kinase (PI3K)/Akt and STAT3 pathways. These results indicated that silencing miR-143 could provide a novel therapeutic strategy for BBB damage-related vascular dysfunction. PMID:27767041

  5. MicroRNA-143 replenishment re-sensitizes colorectal cancer cells harboring mutant, but not wild-type, KRAS to paclitaxel treatment.

    PubMed

    Fei, Bing-Yuan; Wang, Xiu-Ying; Fang, Xue-Dong

    2016-05-01

    Colorectal cancer (CRC) global incidence is one of the highest among cancers. The KRAS gene has been shown as a robust biomarker for poor prognosis and drug resistance. MicroRNA-143 (miR-143) and let-7 are families of tumor suppressor microRNAs that are often downregulated in CRC, especially with coexistent KRAS mutations. In order to evaluate if miR-143 and/or let-7b replenishment would re-sensitize CRC cells to paclitaxel treatment, we investigated in effect of miR-143 and let-7b replenishments on sensitivity to paclitaxel treatment in KRAS mutant LoVo and wild-type SW48 CRC cell lines. Our results showed that miR-143, but not let-7b, increased sensitization of KRAS mutant tumor cells to paclitaxel. Furthermore, transfection of miR-143, but not let-7b, mimic negatively regulated the expression of mutant but not wild-type KRAS. Combination of miR-143 mimic and paclitaxel induced the onset of apoptosis, and reverted in vitro metastatic properties (migration and invasion) in KRAS mutant tumor cells. MiR-143 thus can be used as a chemosensitizer for the treatment of KRAS mutant tumors and warrants further investigations in in vitro and pre-clinical in vivo models.

  6. E-ring 8-isoprostanes are agonists at EP2- and EP4-prostanoid receptors on human airway smooth muscle cells and regulate the release of colony-stimulating factors by activating cAMP-dependent protein kinase.

    PubMed

    Clarke, Deborah L; Belvisi, Maria G; Hardaker, Elizabeth; Newton, Robert; Giembycz, Mark A

    2005-02-01

    8-Isoprostanes are bioactive lipid mediators formed via the nonenzymatic peroxidation of arachidonic acid by free radicals and reactive oxygen species. However, their cognate receptors, biological actions, and signaling pathways are poorly studied. Here, we report the effect of a variety of E- and Falpha-ring 8-isoprostanes on the release of granulocyte/macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) from human airway smooth muscle (HASM) cells stimulated with interleukin-1beta (IL-1beta). The elaboration of GM-CSF and G-CSF by IL-1beta was inhibited and augmented, respectively, in a concentration-dependent manner by 8-iso-prostaglandin (PG) E(1) and 8-iso-PGE(2), but not by 8-iso-PGF(1alpha), 8-iso-PGF(2alpha), and 8-iso-PGF(3)alpha. AH 6809 (6-isopropoxy-9-oxoxanthine-2-carboxylic acid), an EP(1)-/EP(2)-/DP-receptor blocking drug, antagonized the inhibitory effect of 8-iso-PGE(1) and 8-iso-PGE(2) on GM-CSF output with an affinity consistent with an interaction at prostanoid receptors of the EP(2)-subtype. In contrast, the facilitation by 8-iso-PGE(1) and 8-iso-PGE(2) of G-CSF release was unaffected by AH 6809 and the selective EP(4)-receptor antagonist L-161,982 [4'-[3-butyl-5-oxo-1-(2-trifluoromethyl-phenyl)-1,5-dihydro-[1,2,4]triazol-4-ylmethyl]-biphenyl-2-sulfonic acid (3-methyl-thiophene-2-carbonyl)-amide]. However, when used in combination, AH 6809 and L-161,982 displaced 5-fold to the right the 8-iso-PGE and 8-iso-PGE concentration-response curves. The opposing (1)effect of E-ring (2)8-isoprostanes on GM-CSF and G-CSF release was mimicked by 8-bromo-cAMP and abolished in cells infected with an adenovirus vector encoding an inhibitor protein of cAMP-dependent protein kinase (PKA). Together, these data demonstrate that E-ring 8-isoprostanes regulate the secretion of GM-CSF and G-CSF from HASM cells by a cAMP- and PKA-dependent mechanism. Moreover, antagonist studies revealed that 8-iso-PGE(1) and 8-iso-PGE(2

  7. Resting calcium influx in airway smooth muscle.

    PubMed

    Montaño, Luis M; Bazán-Perkins, Blanca

    2005-01-01

    Plasma membrane Ca2+ leak remains the most uncertain of the cellular Ca2+ regulation pathways. During passive Ca2+ influx in non-stimulated smooth muscle cells, basal activity of constitutive Ca2+ channels seems to be involved. In vascular smooth muscle, the 3 following Ca2+ entry pathways contribute to this phenomenon: (i) via voltage-dependent Ca2+ channels, (ii) receptor gated Ca2+ channels, and (iii) store operated Ca2+ channels, although, in airway smooth muscle it seems only 2 passive Ca2+ influx pathways are implicated, one sensitive to SKF 96365 (receptor gated Ca2+ channels) and the other to Ni2+ (store operated Ca2+ channels). Resting Ca2+ entry could provide a sufficient amount of Ca2+ and contribute to resting intracellular Ca2+ concentration ([Ca2+]i), maintenance of the resting membrane potential, myogenic tone, and sarcoplasmic reticulum-Ca2+ refilling. However, further research, especially in airway smooth muscle, is required to better explore the physiological role of this passive Ca2+ influx pathway as it could be involved in airway hyperresponsiveness.

  8. Smooth eigenvalue correction

    NASA Astrophysics Data System (ADS)

    Hendrikse, Anne; Veldhuis, Raymond; Spreeuwers, Luuk

    2013-12-01

    Second-order statistics play an important role in data modeling. Nowadays, there is a tendency toward measuring more signals with higher resolution (e.g., high-resolution video), causing a rapid increase of dimensionality of the measured samples, while the number of samples remains more or less the same. As a result the eigenvalue estimates are significantly biased as described by the Marčenko Pastur equation for the limit of both the number of samples and their dimensionality going to infinity. By introducing a smoothness factor, we show that the Marčenko Pastur equation can be used in practical situations where both the number of samples and their dimensionality remain finite. Based on this result we derive methods, one already known and one new to our knowledge, to estimate the sample eigenvalues when the population eigenvalues are known. However, usually the sample eigenvalues are known and the population eigenvalues are required. We therefore applied one of the these methods in a feedback loop, resulting in an eigenvalue bias correction method. We compare this eigenvalue correction method with the state-of-the-art methods and show that our method outperforms other methods particularly in real-life situations often encountered in biometrics: underdetermined configurations, high-dimensional configurations, and configurations where the eigenvalues are exponentially distributed.

  9. New smooth hybrid inflation

    SciTech Connect

    Lazarides, George; Vamvasakis, Achilleas

    2007-10-15

    We consider the extension of the supersymmetric Pati-Salam model which solves the b-quark mass problem of supersymmetric grand unified models with exact Yukawa unification and universal boundary conditions and leads to the so-called new shifted hybrid inflationary scenario. We show that this model can also lead to a new version of smooth hybrid inflation based only on renormalizable interactions provided that a particular parameter of its superpotential is somewhat small. The potential possesses valleys of minima with classical inclination, which can be used as inflationary paths. The model is consistent with the fitting of the three-year Wilkinson microwave anisotropy probe data by the standard power-law cosmological model with cold dark matter and a cosmological constant. In particular, the spectral index turns out to be adequately small so that it is compatible with the data. Moreover, the Pati-Salam gauge group is broken to the standard model gauge group during inflation and, thus, no monopoles are formed at the end of inflation. Supergravity corrections based on a nonminimal Kaehler potential with a convenient choice of a sign keep the spectral index comfortably within the allowed range without generating maxima and minima of the potential on the inflationary path. So, unnatural restrictions on the initial conditions for inflation can be avoided.

  10. Astrophysical smooth particle hydrodynamics

    NASA Astrophysics Data System (ADS)

    Rosswog, Stephan

    2009-04-01

    The paper presents a detailed review of the smooth particle hydrodynamics (SPH) method with particular focus on its astrophysical applications. We start by introducing the basic ideas and concepts and thereby outline all ingredients that are necessary for a practical implementation of the method in a working SPH code. Much of SPH's success relies on its excellent conservation properties and therefore the numerical conservation of physical invariants receives much attention throughout this review. The self-consistent derivation of the SPH equations from the Lagrangian of an ideal fluid is the common theme of the remainder of the text. We derive a modern, Newtonian SPH formulation from the Lagrangian of an ideal fluid. It accounts for changes of the local resolution lengths which result in corrective, so-called "grad-h-terms". We extend this strategy to special relativity for which we derive the corresponding grad-h equation set. The variational approach is further applied to a general-relativistic fluid evolving in a fixed, curved background space-time. Particular care is taken to explicitly derive all relevant equations in a coherent way.

  11. Ceramic coatings on smooth surfaces

    NASA Technical Reports Server (NTRS)

    Miller, R. A. (Inventor); Brindley, W. J. (Inventor); Rouge, C. J. (Inventor)

    1991-01-01

    A metallic coating is plasma sprayed onto a smooth surface of a metal alloy substitute or on a bond coating. An initial thin ceramic layer is low pressure sprayed onto the smooth surface of the substrate or bond coating. Another ceramic layer is atmospheric plasma sprayed onto the initial ceramic layer.

  12. Smooth muscle phenotypic modulation--a personal experience.

    PubMed

    Campbell, Julie H; Campbell, Gordon R

    2012-08-01

    The idea that smooth muscle cells can exist in multiple phenotypic states depending on the functional demands placed upon them has been around for >5 decades. However, much of the literature today refers to only recent articles, giving the impression that it is a new idea. At the same time, the current trend is to delve deeper and deeper into transcriptional regulation of smooth muscle genes, and much of the work describing the change in biology of the cells in the different phenotypic states does not appear to be known. This loss of historical perspective regarding the biology of smooth muscle phenotypic modulation is what the current article has tried to mitigate.

  13. Simple Robust Fixed Lag Smoothing

    DTIC Science & Technology

    1988-12-02

    SIMPLE ROBUST FIXED LAG SMOOTHING by ~N. D. Le R.D. Martin 4 TECHNICAL RlEPORT No. 149 December 1988 Department of Statistics, GN-22 Accesion For...frLsD1ist Special A- Z Simple Robust Fixed Lag Smoothing With Application To Radar Glint Noise * N. D. Le R. D. Martin Department of Statistics, GN...smoothers. The emphasis here is on fixed-lag smoothing , as opposed to the use of existing robust fixed interval smoothers (e.g., as in Martin, 1979

  14. Notch Signaling in Vascular Smooth Muscle Cells.

    PubMed

    Baeten, J T; Lilly, B

    2017-01-01

    The Notch signaling pathway is a highly conserved pathway involved in cell fate determination in embryonic development and also functions in the regulation of physiological processes in several systems. It plays an especially important role in vascular development and physiology by influencing angiogenesis, vessel patterning, arterial/venous specification, and vascular smooth muscle biology. Aberrant or dysregulated Notch signaling is the cause of or a contributing factor to many vascular disorders, including inherited vascular diseases, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, associated with degeneration of the smooth muscle layer in cerebral arteries. Like most signaling pathways, the Notch signaling axis is influenced by complex interactions with mediators of other signaling pathways. This complexity is also compounded by different members of the Notch family having both overlapping and unique functions. Thus, it is vital to fully understand the roles and interactions of each Notch family member in order to effectively and specifically target their exact contributions to vascular disease. In this chapter, we will review the Notch signaling pathway in vascular smooth muscle cells as it relates to vascular development and human disease.

  15. Radar data smoothing filter study

    NASA Technical Reports Server (NTRS)

    White, J. V.

    1984-01-01

    The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.

  16. Active controls for ride smoothing

    NASA Technical Reports Server (NTRS)

    Conner, D. W.; Thompson, G. O.

    1976-01-01

    Active controls technology offers great promise for significantly smoothing the ride, and thus improving public and air carrier acceptance, of certain types of transport aircraft. Recent findings which support this promise are presented in the following three pertinent areas: (1) Ride quality versus degree of traveler satisfaction; (2) significant findings from a feasibility study of a ride smoothing system; and (3) potential ride problems identified for several advanced transport concepts.

  17. An invertebrate smooth muscle with striated muscle myosin filaments

    PubMed Central

    Sulbarán, Guidenn; Alamo, Lorenzo; Pinto, Antonio; Márquez, Gustavo; Méndez, Franklin; Padrón, Raúl; Craig, Roger

    2015-01-01

    Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components. PMID:26443857

  18. An invertebrate smooth muscle with striated muscle myosin filaments.

    PubMed

    Sulbarán, Guidenn; Alamo, Lorenzo; Pinto, Antonio; Márquez, Gustavo; Méndez, Franklin; Padrón, Raúl; Craig, Roger

    2015-10-20

    Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components.

  19. Income Smoothing: Methodology and Models.

    DTIC Science & Technology

    1986-05-01

    that managers desire a pattern % of income that has low variability relative to a linear time trend. 2. Industry Trend. Target 2 assumes that firms...R167 55? INCOME SMOOTHING: METHODOLOGY ND NODELS(U) UMVL in1POSTGRADUATE SCHOOL MONTEREY CA 0 D HOSES "AY S6 UNCLASSIFIED NP5-604FO53 E * I* vu...California oCiD ELEC fl MAY 12 986 INCOME SMOOTHING - METHODOLOGY AND MODELS by 0. Douglas Moses May 1986 *Approved frpublic release; ditibto uniie

  20. Registration of 'Newell' Smooth Bromegrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Newell’ (Reg. No. CV-xxxx, PI 671851) smooth bromegrass (Bromus inermis Leyss.) is a steppe or southern type cultivar that is primarily adapted in the USA to areas north of 40o N lat. and east of 100o W long. that have 500 mm or more annual precipitation or in areas that have similar climate cond...

  1. Smooth muscle alpha-actinin interaction with smitin.

    PubMed

    Chi, Richard J; Olenych, Scott G; Kim, Kyoungtae; Keller, Thomas C S

    2005-07-01

    Actin-myosin II filament-based contractile structures in striated muscle, smooth muscle, and nonmuscle cells also contain the actin filament-crosslinking protein alpha-actinin. In striated muscle sarcomeres, interactions between the myosin-binding protein titin and alpha-actinin in the Z-line provide an important structural linkage. We previously discovered a titin-like protein, smitin, associated with the contractile apparatus of smooth muscle cells. Purified native smooth muscle alpha-actinin binds with nanomolar affinity to smitin in smitin-myosin coassemblies in vitro. Smooth muscle alpha-actinin also interacts with striated muscle titin. In contrast to striated muscle alpha-actinin interaction with titin and smitin, which is significantly enhanced by PIP2, smooth muscle alpha-actinin interacts with smitin and titin equally well in the presence and absence of PIP2. Using expressed regions of smooth muscle alpha-actinin, we have demonstrated smitin-binding sites in the smooth muscle alpha-actinin R2-R3 spectrin-like repeat rod domain and a C-terminal domain formed by cryptic EF-hand structures. These smitin-binding sites are highly homologous to the titin-binding sites of striated muscle alpha-actinin. Our results suggest that direct interaction between alpha-actinin and titin or titin-like proteins is a common feature of actin-myosin II contractile structures in striated muscle and smooth muscle cells and that the molecular bases for alpha-actinin interaction with these proteins are similar, although regulation of these interactions may differ according to tissue.

  2. Analytic elements of smooth shapes

    NASA Astrophysics Data System (ADS)

    Strack, Otto D. L.; Nevison, Patrick R.

    2015-10-01

    We present a method for producing analytic elements of a smooth shape, obtained using conformal mapping. Applications are presented for a case of impermeable analytic elements as well as for head-specified ones. The mathematical operations necessary to use the elements in practical problems can be carried out before modeling of flow problems begins. A catalog of shapes, along with pre-determined coefficients could be established on the basis of the approach presented here, making applications in the field straight forward.

  3. Programming smooth muscle plasticity with chromatin dynamics.

    PubMed

    McDonald, Oliver G; Owens, Gary K

    2007-05-25

    Smooth muscle cells (SMCs) possess remarkable phenotypic plasticity that allows rapid adaptation to fluctuating environmental cues. For example, vascular SMCs undergo profound changes in their phenotype during neointimal formation in response to vessel injury or within atherosclerotic plaques. Recent studies have shown that interaction of serum response factor (SRF) and its numerous accessory cofactors with CArG box DNA sequences within promoter chromatin of SMC genes is a nexus for integrating signals that influence SMC differentiation in development and disease. During development, SMC-restricted sets of posttranslational histone modifications are acquired within the CArG box chromatin of SMC genes. These modifications in turn control the chromatin-binding properties of SRF. The histone modifications appear to encode a SMC-specific epigenetic program that is used by extracellular cues to influence SMC differentiation, by regulating binding of SRF and its partners to the chromatin template. Thus, SMC differentiation is dynamically regulated by the interplay between SRF accessory cofactors, the SRF-CArG interaction, and the underlying histone modification program. As such, the inherent plasticity of the SMC lineage offers unique glimpses into how cellular differentiation is dynamically controlled at the level of chromatin within the context of changing microenvironments. Further elucidation of how chromatin regulates SMC differentiation will undoubtedly yield valuable insights into both normal developmental processes and the pathogenesis of several vascular diseases that display detrimental SMC phenotypic behavior.

  4. Novel treatment strategies for smooth muscle disorders: Targeting Kv7 potassium channels.

    PubMed

    Haick, Jennifer M; Byron, Kenneth L

    2016-09-01

    Smooth muscle cells provide crucial contractile functions in visceral, vascular, and lung tissues. The contractile state of smooth muscle is largely determined by their electrical excitability, which is in turn influenced by the activity of potassium channels. The activity of potassium channels sustains smooth muscle cell membrane hyperpolarization, reducing cellular excitability and thereby promoting smooth muscle relaxation. Research over the past decade has indicated an important role for Kv7 (KCNQ) voltage-gated potassium channels in the regulation of the excitability of smooth muscle cells. Expression of multiple Kv7 channel subtypes has been demonstrated in smooth muscle cells from viscera (gastrointestinal, bladder, myometrial), from the systemic and pulmonary vasculature, and from the airways of the lung, from multiple species, including humans. A number of clinically used drugs, some of which were developed to target Kv7 channels in other tissues, have been found to exert robust effects on smooth muscle Kv7 channels. Functional studies have indicated that Kv7 channel activators and inhibitors have the ability to relax and contact smooth muscle preparations, respectively, suggesting a wide range of novel applications for the pharmacological tool set. This review summarizes recent findings regarding the physiological functions of Kv7 channels in smooth muscle, and highlights potential therapeutic applications based on pharmacological targeting of smooth muscle Kv7 channels throughout the body.

  5. Effectiveness of Analytic Smoothing in Equipercentile Equating.

    ERIC Educational Resources Information Center

    Kolen, Michael J.

    1984-01-01

    An analytic procedure for smoothing in equipercentile equating using cubic smoothing splines is described and illustrated. The effectiveness of the procedure is judged by comparing the results from smoothed equipercentile equating with those from other equating methods using multiple cross-validations for a variety of sample sizes. (Author/JKS)

  6. 7 CFR 51.768 - Smooth texture.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Smooth texture. Smooth texture means that the skin is thin and smooth for the variety and size of the fruit. “Thin” means that the skin thickness does not average more than 3/8 inch (9.5 mm), on a...

  7. 7 CFR 51.768 - Smooth texture.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Smooth texture. Smooth texture means that the skin is thin and smooth for the variety and size of the fruit. “Thin” means that the skin thickness does not average more than 3/8 inch (9.5 mm), on a...

  8. Beamline smoothing of the Advanced Photon Source

    SciTech Connect

    Friedsam, H.; Penicka, M.; Zhao, S.

    1995-06-01

    This paper outlines a general beamline smoothing concept based on the use of First Principle Component analysis. Bean-dine smoothing is commonly used for the detection of blunders in the positioning of beam elements and to provide a smooth particle beam path with the fewest adjustments to individual beam components. It also provides the data for assessment of the achieved positioning quality.

  9. A SAS IML Macro for Loglinear Smoothing

    ERIC Educational Resources Information Center

    Moses, Tim; von Davier, Alina

    2011-01-01

    Polynomial loglinear models for one-, two-, and higher-way contingency tables have important applications to measurement and assessment. They are essentially regarded as a smoothing technique, which is commonly referred to as loglinear smoothing. A SAS IML (SAS Institute, 2002a) macro was created to implement loglinear smoothing according to…

  10. Extracellular mechanism through the Edg family of receptors might be responsible for sphingosine-1-phosphate-induced regulation of DNA synthesis and migration of rat aortic smooth-muscle cells.

    PubMed Central

    Tamama, K; Kon, J; Sato, K; Tomura, H; Kuwabara, A; Kimura, T; Kanda, T; Ohta, H; Ui, M; Kobayashi, I; Okajima, F

    2001-01-01

    Exogenous sphingosine 1-phosphate (S1P) increased cytosolic Ca(2+) concentration, stimulated thymidine incorporation (DNA synthesis) and inhibited cell migration in rat aortic smooth-muscle cells (AoSMCs). Although exogenous sphingosine, a substrate of sphingosine kinase or a precursor of S1P, markedly induced the intracellular accumulation of S1P, the lipid failed to mimic the S1P-induced actions. In contrast, dihydrosphingosine 1-phosphate (DHS1P), an S1P receptor agonist, duplicated these S1P actions even though DHS1P was approx. 20-50-fold less potent than S1P. The pharmacological properties of DHS1P for the S1P receptor subtypes Edg-1, Edg-3, Edg-5 and Edg-6 were compared in Chinese hamster ovary (CHO) cells that were overexpressing the respective receptor. In these S1P-receptor-overexpressing cells, DHS1P was approx. 20-30-fold less potent than S1P for the displacement of [(3)H]S1P binding and inositol phosphate response in Edg-5-expressing CHO cells, as was the case for AoSMCs. However, it was slightly (not more than 3-fold) less potent than S1P in cells expressing Edg-1, Edg-3 or Edg-6. Of the above-mentioned four types of S1P receptor, Edg-5 was abundantly expressed in AoSMCs, as demonstrated by Northern blotting. These results suggest that the intracellular accumulation of S1P is not necessary for the S1P-induced Ca(2+) response, for the stimulation of DNA synthesis or for the inhibition of cell migration. Thus these S1P-induced actions might be mediated through extracellular (or cell-surface) S1P receptors in AoSMCs: Edg-5 might be a most important receptor subtype. PMID:11115407

  11. Leptogenesis in smooth hybrid inflation

    NASA Astrophysics Data System (ADS)

    Jeannerot, R.; Khalil, S.; Lazarides, G.

    2001-05-01

    We present a concrete supersymmetric grand unified model based on the Pati-Salam gauge group SU(4)c×SU(2)L×SU(2)R and leading naturally to smooth hybrid inflation, which avoids the cosmological disaster encountered in the standard hybrid inflationary scenario from the overproduction of monopoles at the end of inflation. Successful `reheating' which satisfies the gravitino constraint takes place after the termination of inflation. Also, adequate baryogenesis via a primordial leptogenesis occurs consistently with the solar and atmospheric neutrino oscillation data as well as the SU(4)c symmetry.

  12. Sirtuin 3 (SIRT3) Regulates α-Smooth Muscle Actin (α-SMA) Production through the Succinate Dehydrogenase-G Protein-coupled Receptor 91 (GPR91) Pathway in Hepatic Stellate Cells.

    PubMed

    Li, Ying Hui; Choi, Dae Hee; Lee, Eun Hye; Seo, Su Ryeon; Lee, Seungkoo; Cho, Eun-Hee

    2016-05-06

    Sirtuin 3 (SIRT3) is an NAD(+)-dependent protein deacetylase. Recent studies have shown that SIRT3 expression is decreased in nonalcoholic fatty liver disease (NAFLD). Moreover, SIRT3 is a key regulator of succinate dehydrogenase (SDH), which catalyzes the oxidation of succinate to fumarate. Increased succinate concentrations and the specific G protein-coupled receptor 91 (GPR91) are involved in the activation of hepatic stellate cells (HSCs). In this study, we aimed to establish whether SIRT3 regulated the SDH activity, succinate, and GPR91 expression in HSCs and an animal model of NAFLD. Our goal was also to determine whether succinate released from hepatocytes regulated HSC activation. Inhibiting SIRT3 using SIRT3 siRNA exacerbated HSC activation via the SDH-succinate-GPR91 pathway, and SIRT3 overexpression or honokiol treatment attenuated HSC activation in vitro In isolated liver and HSCs from methionine- and choline-deficient (MCD) diet-induced NAFLD, the expression of SIRT3 and SDH activity was decreased, and the succinate concentrations and GPR91 expression were increased. Moreover, we found that GPR91 knockdown or resveratrol treatment improved the steatosis in MCD diet-fed mice. This investigation revealed a novel mechanism of the SIRT3-SDH-GPR91 cascade in MCD diet-induced HSC activation in NAFLD. These findings highlight the biological significance of novel strategies aimed at targeting SIRT3 and GPR91 in HSCs with the goal of improving NAFLD treatment.

  13. Regulation of Gβγi-dependent PLC-β3 activity in smooth muscle: inhibitory phosphorylation of PLC-β3 by PKA and PKG and stimulatory phosphorylation of Gαi-GTPase-activating protein RGS2 by PKG.

    PubMed

    Nalli, Ancy D; Kumar, Divya P; Al-Shboul, Othman; Mahavadi, Sunila; Kuemmerle, John F; Grider, John R; Murthy, Karnam S

    2014-11-01

    In gastrointestinal smooth muscle, agonists that bind to Gi-coupled receptors activate preferentially PLC-β3 via Gβγ to stimulate phosphoinositide (PI) hydrolysis and generate inositol 1,4,5-trisphosphate (IP3) leading to IP3-dependent Ca(2+) release and muscle contraction. In the present study, we identified the mechanism of inhibition of PLC-β3-dependent PI hydrolysis by cAMP-dependent protein kinase (PKA) and cGMP-dependent protein kinase (PKG). Cyclopentyl adenosine (CPA), an adenosine A1 receptor agonist, caused an increase in PI hydrolysis in a concentration-dependent fashion; stimulation was blocked by expression of the carboxyl-terminal sequence of GRK2(495-689), a Gβγ-scavenging peptide, or Gαi minigene but not Gαq minigene. Isoproterenol and S-nitrosoglutathione (GSNO) induced phosphorylation of PLC-β3 and inhibited CPA-induced PI hydrolysis, Ca(2+) release, and muscle contraction. The effect of isoproterenol on all three responses was inhibited by PKA inhibitor, myristoylated PKI, or AKAP inhibitor, Ht-31, whereas the effect of GSNO was selectively inhibited by PKG inhibitor, Rp-cGMPS. GSNO, but not isoproterenol, also phosphorylated Gαi-GTPase-activating protein, RGS2, and enhanced association of Gαi3-GTP and RGS2. The effect of GSNO on PI hydrolysis was partly reversed in cells (i) expressing constitutively active GTPase-resistant Gαi mutant (Q204L), (ii) phosphorylation-site-deficient RGS2 mutant (S46A/S64A), or (iii) siRNA for RGS2. We conclude that PKA and PKG inhibit Gβγi-dependent PLC-β3 activity by direct phosphorylation of PLC-β3. PKG, but not PKA, also inhibits PI hydrolysis indirectly by a mechanism involving phosphorylation of RGS2 and its association with Gαi-GTP. This allows RGS2 to accelerate Gαi-GTPase activity, enhance Gαβγi trimer formation, and inhibit Gβγi-dependent PLC-β3 activity.

  14. Improving smoothing efficiency of rigid conformal polishing tool using time-dependent smoothing evaluation model

    NASA Astrophysics Data System (ADS)

    Song, Chi; Zhang, Xuejun; Zhang, Xin; Hu, Haifei; Zeng, Xuefeng

    2017-01-01

    A rigid conformal (RC) lap can smooth mid-spatial-frequency (MSF) errors, which are naturally smaller than the tool size, while still removing large-scale errors in a short time. However, the RC-lap smoothing efficiency performance is poorer than expected, and existing smoothing models cannot explicitly specify the methods to improve this efficiency. We presented an explicit time-dependent smoothing evaluation model that contained specific smoothing parameters directly derived from the parametric smoothing model and the Preston equation. Based on the time-dependent model, we proposed a strategy to improve the RC-lap smoothing efficiency, which incorporated the theoretical model, tool optimization, and efficiency limit determination. Two sets of smoothing experiments were performed to demonstrate the smoothing efficiency achieved using the time-dependent smoothing model. A high, theory-like tool influence function and a limiting tool speed of 300 RPM were o

  15. Smooth halos in the cosmic web

    NASA Astrophysics Data System (ADS)

    Gaite, José

    2015-04-01

    Dark matter halos can be defined as smooth distributions of dark matter placed in a non-smooth cosmic web structure. This definition of halos demands a precise definition of smoothness and a characterization of the manner in which the transition from smooth halos to the cosmic web takes place. We introduce entropic measures of smoothness, related to measures of inequality previously used in economy and with the advantage of being connected with standard methods of multifractal analysis already used for characterizing the cosmic web structure in cold dark matter N-body simulations. These entropic measures provide us with a quantitative description of the transition from the small scales portrayed as a distribution of halos to the larger scales portrayed as a cosmic web and, therefore, allow us to assign definite sizes to halos. However, these ``smoothness sizes'' have no direct relation to the virial radii. Finally, we discuss the influence of N-body discreteness parameters on smoothness.

  16. Smooth halos in the cosmic web

    SciTech Connect

    Gaite, José

    2015-04-01

    Dark matter halos can be defined as smooth distributions of dark matter placed in a non-smooth cosmic web structure. This definition of halos demands a precise definition of smoothness and a characterization of the manner in which the transition from smooth halos to the cosmic web takes place. We introduce entropic measures of smoothness, related to measures of inequality previously used in economy and with the advantage of being connected with standard methods of multifractal analysis already used for characterizing the cosmic web structure in cold dark matter N-body simulations. These entropic measures provide us with a quantitative description of the transition from the small scales portrayed as a distribution of halos to the larger scales portrayed as a cosmic web and, therefore, allow us to assign definite sizes to halos. However, these ''smoothness sizes'' have no direct relation to the virial radii. Finally, we discuss the influence of N-body discreteness parameters on smoothness.

  17. s-SMOOTH: Sparsity and Smoothness Enhanced EEG Brain Tomography

    PubMed Central

    Li, Ying; Qin, Jing; Hsin, Yue-Loong; Osher, Stanley; Liu, Wentai

    2016-01-01

    EEG source imaging enables us to reconstruct current density in the brain from the electrical measurements with excellent temporal resolution (~ ms). The corresponding EEG inverse problem is an ill-posed one that has infinitely many solutions. This is due to the fact that the number of EEG sensors is usually much smaller than that of the potential dipole locations, as well as noise contamination in the recorded signals. To obtain a unique solution, regularizations can be incorporated to impose additional constraints on the solution. An appropriate choice of regularization is critically important for the reconstruction accuracy of a brain image. In this paper, we propose a novel Sparsity and SMOOthness enhanced brain TomograpHy (s-SMOOTH) method to improve the reconstruction accuracy by integrating two recently proposed regularization techniques: Total Generalized Variation (TGV) regularization and ℓ1−2 regularization. TGV is able to preserve the source edge and recover the spatial distribution of the source intensity with high accuracy. Compared to the relevant total variation (TV) regularization, TGV enhances the smoothness of the image and reduces staircasing artifacts. The traditional TGV defined on a 2D image has been widely used in the image processing field. In order to handle 3D EEG source images, we propose a voxel-based Total Generalized Variation (vTGV) regularization that extends the definition of second-order TGV from 2D planar images to 3D irregular surfaces such as cortex surface. In addition, the ℓ1−2 regularization is utilized to promote sparsity on the current density itself. We demonstrate that ℓ1−2 regularization is able to enhance sparsity and accelerate computations than ℓ1 regularization. The proposed model is solved by an efficient and robust algorithm based on the difference of convex functions algorithm (DCA) and the alternating direction method of multipliers (ADMM). Numerical experiments using synthetic data demonstrate the

  18. Standard-smooth hybrid inflation

    SciTech Connect

    Lazarides, George; Vamvasakis, Achilleas

    2007-12-15

    We consider the extended supersymmetric Pati-Salam model which, for {mu}>0 and universal boundary conditions, succeeds to yield experimentally acceptable b-quark masses by moderately violating Yukawa unification. It is known that this model can lead to new shifted or new smooth hybrid inflation. We show that a successful two-stage inflationary scenario can be realized within this model based only on renormalizable superpotential interactions. The cosmological scales exit the horizon during the first stage of inflation, which is of the standard hybrid type and takes place along the trivial flat direction with the inflaton driven by radiative corrections. Spectral indices compatible with the recent data can be achieved in global supersymmetry or minimal supergravity by restricting the number of e-foldings of our present horizon during the first inflationary stage. The additional e-foldings needed for solving the horizon and flatness problems are naturally provided by a second stage of inflation, which occurs mainly along the built-in new smooth hybrid inflationary path appearing right after the destabilization of the trivial flat direction at its critical point. Monopoles are formed at the end of the first stage of inflation and are, subsequently, diluted by the second stage of inflation to become utterly negligible in the present universe for almost all (for all) the allowed values of the parameters in the case of global supersymmetry (minimal supergravity)

  19. Lensing smoothing of BAO wiggles

    NASA Astrophysics Data System (ADS)

    Di Dio, Enea

    2017-03-01

    We study non-perturbatively the effect of the deflection angle on the BAO wiggles of the matter power spectrum in real space. We show that from redshift z~2 this introduces a dispersion of roughly 1 Mpc at BAO scale, which corresponds approximately to a 1% effect. The lensing effect induced by the deflection angle, which is completely geometrical and survey independent, smears out the BAO wiggles. The effect on the power spectrum amplitude at BAO scale is about 0.1 % for z~2 and 0.2 % for z~4. We compare the smoothing effects induced by the lensing potential and non-linear structure formation, showing that the two effects become comparable at z ~ 4, while the lensing effect dominates for sources at higher redshifts. We note that this effect is not accounted through BAO reconstruction techniques.

  20. Autoregressive smoothing of GOMOS transmittances

    NASA Astrophysics Data System (ADS)

    Fussen, D.; Vanhellemont, F.; Bingen, C.; Kyrölä, B.; Tamminen, J.; Sofieva, V.; Hassinen, S.; Seppälä, A.; Verronen, P. T.; Bertaux, J. L.; Hauchecorne, A.; Dalaudier, F.; d'Andon, O. Fanton; Barrot, G.; Mangin, A.; Theodore, B.; Guirlet, M.; Renard, J. B.; Fraisse, R.; Snoeij, P.; Koopman, R.; Saavedra, L.

    GOMOS is a stellar occultation instrument onboard ENVISAT. It has already measured several hundreds of thousands occultations since March 2002. In some circumstances, the obliqueness of the star setting causes the remote sounding of possible horizontal turbulence that cannot be adequately corrected by using the fast photometer signals, leading to the presence of residual scintillation in the atmospheric transmittance. We investigate the mechanism that produces this spurious signal that may cause the retrieval of wavy constituent profiles. A special algorithm of vertical autoregressive smoothing (VAS) is proposed that takes into account the physical correlation between adjacent measurements at different tangent altitudes. A regularization parameter of the method may be optimized on basis of the minimal correlation between the residuals as prescribed by the Durbin-Watson statistics. The improvements obtained in the retrieval of both O 3 and NO 2 number density profiles is presented and discussed with respect to the results of the official data processing model.

  1. Smoothing and the second law

    NASA Technical Reports Server (NTRS)

    Merriam, Marshal L.

    1987-01-01

    The technique of obtaining second-order oscillation-free total -variation-diminishing (TVD), scalar difference schemes by adding a limited diffusive flux ('smoothing') to a second-order centered scheme is explored. It is shown that such schemes do not always converge to the correct physical answer. The approach presented here is to construct schemes that numerically satisfy the second law of thermodynamics on a cell-by-cell basis. Such schemes can only converge to the correct physical solution and in some cases can be shown to be TVD. An explicit scheme with this property and second-order spatial accuracy was found to have extremely restrictive time-step limitation. Switching to an implicit scheme removed the time-step limitation.

  2. Smoothing and the second law

    NASA Technical Reports Server (NTRS)

    Merriam, Marshal L.

    1986-01-01

    The technique of obtaining second order, oscillation free, total variation diminishing (TVD), scalar difference schemes by adding a limited diffusion flux (smoothing) to a second order centered scheme is explored. It is shown that such schemes do not always converge to the correct physical answer. The approach presented here is to construct schemes that numerically satisfy the second law of thermodynamics on a cell by cell basis. Such schemes can only converge to the correct physical solution and in some cases can be shown to be TVD. An explicit scheme with this property and second order spatial accuracy was found to have an extremely restrictive time step limitation (Delta t less than Delta x squared). Switching to an implicit scheme removed the time step limitation.

  3. The Smooth Muscle of the Artery

    DTIC Science & Technology

    1975-01-01

    to keep up with inter- national standards. The German Cancer Research Center as well as the Hax-Planck Inntitutes of Heidelberg are well equipped to...SOMLYO: I plan to briefly review some of the aspects of normal function of vascular smooth muscle with particular ---- I SMOOTH MUSCLE STRUCTURE 35...schematic review of the data on catabolism in connective tissue cells smooth muscle cells. The increasing number of electron microscopic studies of

  4. Smooth GERBS, orthogonal systems and energy minimization

    NASA Astrophysics Data System (ADS)

    Dechevsky, Lubomir T.; Zanaty, Peter

    2013-12-01

    New results are obtained in three mutually related directions of the rapidly developing theory of generalized expo-rational B-splines (GERBS) [7, 6]: closed-form computability of C∞-smooth GERBS in terms of elementary and special functions, Hermite interpolation and least-squares best approximation via smooth GERBS, energy minimizing properties of smooth GERBS similar to those of the classical cubic polynomial B-splines.

  5. Smooth GERBS, orthogonal systems and energy minimization

    SciTech Connect

    Dechevsky, Lubomir T. E-mail: pza@hin.no; Zanaty, Peter E-mail: pza@hin.no

    2013-12-18

    New results are obtained in three mutually related directions of the rapidly developing theory of generalized expo-rational B-splines (GERBS) [7, 6]: closed-form computability of C{sup ∞}-smooth GERBS in terms of elementary and special functions, Hermite interpolation and least-squares best approximation via smooth GERBS, energy minimizing properties of smooth GERBS similar to those of the classical cubic polynomial B-splines.

  6. MicroRNA Delivery Strategies to the Lung in a Model of Pulmonary Hypertension.

    PubMed

    Deng, Lin; Baker, Andrew H; Bradshaw, Angela C

    2017-01-01

    Pulmonary arterial hypertension (PAH) is characterized by enhanced proliferation of pulmonary artery smooth muscle cells and endothelial cells associated with obliteration of small pulmonary arterioles and formation of plexiform lesions. To date, no curative treatments have been identified for pulmonary arterial hypertension. There are various therapeutic options, including conventional medical therapies and oral, subcutaneous, intravenous, and inhalation delivery. We have previously shown that miR-143/145 knockout can prevent the development of chronic hypoxia-induced pulmonary hypertension (PH) in mice. Here, we use chronic hypoxia-induced PH as a disease model to evaluate miR-143/145 inhibition after delivery of antimiRNAs via the subcutaneous or intranasal routes. We use qRT-PCR and immunofluorescence to confirm that both delivery strategies efficiently inhibit miR-143/145 in lung tissue from mice with chronic hypoxia-induced PH.

  7. Cl− channels in smooth muscle cells

    PubMed Central

    Bulley, Simon

    2013-01-01

    In smooth muscle cells (SMCs), the intracellular chloride ion (Cl−) concentration is high due to accumulation by Cl−/HCO3− exchange and Na+, K+, Cl− cotransportation. The equilibrium potential for Cl− (ECl) is more positive than physiological membrane potentials (Em), with Cl− efflux inducing membrane depolarization. Early studies used electrophysiology and non-specific antagonists to study the physiological relevance of Cl− channels in SMCs. More recent reports have incorporated molecular biological approaches to identify and determine the functional significance of several different Cl− channels. Both “classic” and cGMP-dependent calcium (Ca2+)-activated (ClCa) channels and volume-sensitive Cl− channels are present, with TMEM16A/ANO1, bestrophins and ClC-3, respectively, proposed as molecular candidates for these channels. The cystic fibrosis transmembrane conductance regulator (CFTR) has also been described in SMCs. This review will focus on discussing recent progress made in identifying each of these Cl− channels in SMCs, their physiological functions, and contribution to diseases that modify contraction, apoptosis and cell proliferation. PMID:24077695

  8. Smooth Passage For The Jetfoil

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The Flying Princess is a Boeing Jetfoil, one of a family of commercial waterjets built by Boeing Marine Systems, a division of The Boeing Company, Seattle, Washington. The new Jetfoil offers a number of advantages over earlier hydrofoils, a major one being a smooth ride in rough waters. NASA technology contributed to jolt-free passenger comfort. Hydrofoils skim the surface at speeds considerably greater than those of conventional ships because there is little friction between hull and water. Hulls are raised above the water by the lift of the foils, which resemble and function like an airplane wing. The foils are attached to the hull by rigid struts, which ordinarily cause a vessel operating in coastal seas to follow the contour of the waves. In wind-whipped waters, this makes for a rough ride. Seeking to increase passenger acceptance, Boeing Marine System engineers looked for ways to improve rough-water ride quality. Langley Research Center conducts continuing ride quality research. Initially, it was aimed at improving aircraft ride; it was later expanded to include all modes of transportation. Research includes studies of vibration, acceleration, temperature, humidity, passenger seats and posture, and the psychological aspects of passenger reaction to vehicle ride. As part of the program, Langley developed instrumentation, ride quality models and methods of data analysis.

  9. Smooth horizons and quantum ripples

    NASA Astrophysics Data System (ADS)

    Golovnev, Alexey

    2015-05-01

    Black holes are unique objects which allow for meaningful theoretical studies of strong gravity and even quantum gravity effects. An infalling and a distant observer would have very different views on the structure of the world. However, a careful analysis has shown that it entails no genuine contradictions for physics, and the paradigm of observer complementarity has been coined. Recently this picture was put into doubt. In particular, it was argued that in old black holes a firewall must form in order to protect the basic principles of quantum mechanics. This AMPS paradox has already been discussed in a vast number of papers with different attitudes and conclusions. Here we want to argue that a possible source of confusion is the neglect of quantum gravity effects. Contrary to widespread perception, it does not necessarily mean that effective field theory is inapplicable in rather smooth neighbourhoods of large black hole horizons. The real offender might be an attempt to consistently use it over the huge distances from the near-horizon zone of old black holes to the early radiation. We give simple estimates to support this viewpoint and show how the Page time and (somewhat more speculative) scrambling time do appear.

  10. Fourier smoothing of digital photographic spectra

    NASA Astrophysics Data System (ADS)

    Anupama, G. C.

    1990-03-01

    Fourier methods of smoothing one-dimensional data are discussed with particular reference to digital photographic spectra. Data smoothed using lowpass filters with different cut-off frequencies are intercompared. A method to scale densities in order to remove the dependence of grain noise on density is described. Optimal filtering technique which models signal and noise in Fourier domain is also explained.

  11. Smoothing the output from a DAC

    NASA Technical Reports Server (NTRS)

    Wagner, C.

    1980-01-01

    Circuit smooths stepped waveform from analog-to-digital converter without appreciable phase shift between stepped input signal and smoothed output signal and without any effect from stepping rate. Waveform produced is suitable for driving controls used in manufacturing processes, aerospace systems, and automobiles.

  12. Myosin filament structure in vertebrate smooth muscle

    PubMed Central

    1996-01-01

    The in vivo structure of the myosin filaments in vertebrate smooth muscle is unknown. Evidence from purified smooth muscle myosin and from some studies of intact smooth muscle suggests that they may have a nonhelical, side-polar arrangement of crossbridges. However, the bipolar, helical structure characteristic of myosin filaments in striated muscle has not been disproved for smooth muscle. We have used EM to investigate this question in a functionally diverse group of smooth muscles (from the vascular, gastrointestinal, reproductive, and visual systems) from mammalian, amphibian, and avian species. Intact muscle under physiological conditions, rapidly frozen and then freeze substituted, shows many myosin filaments with a square backbone in transverse profile. Transverse sections of fixed, chemically skinned muscles also show square backbones and, in addition, reveal projections (crossbridges) on only two opposite sides of the square. Filaments gently isolated from skinned smooth muscles and observed by negative staining show crossbridges with a 14.5-nm repeat projecting in opposite directions on opposite sides of the filament. Such filaments subjected to low ionic strength conditions show bare filament ends and an antiparallel arrangement of myosin tails along the length of the filament. All of these observations are consistent with a side-polar structure and argue against a bipolar, helical crossbridge arrangement. We conclude that myosin filaments in all smooth muscles, regardless of function, are likely to be side-polar. Such a structure could be an important factor in the ability of smooth muscles to contract by large amounts. PMID:8698822

  13. Thermal smoothing of rough surfaces in vacuo

    NASA Technical Reports Server (NTRS)

    Wahl, G.

    1986-01-01

    The derivation of equations governing the smoothing of rough surfaces, based on Mullins' (1957, 1960, and 1963) theories of thermal grooving and of capillarity-governed solid surface morphology is presented. As an example, the smoothing of a one-dimensional sine-shaped surface is discussed.

  14. Ion channels in gastrointestinal smooth muscle and interstitial cells of Cajal.

    PubMed

    Lyford, Gregory L; Farrugia, Gianrico

    2003-12-01

    A requirement for normal gastrointestinal motility is the tight regulation of ion channels expressed in interstitial cells of Cajal and smooth muscle. Interstitial cells of Cajal generate the slow wave and amplify neuronal signals; smooth muscle functions as the final effector organ. Recent advances in our understanding of the expression and mechano-regulation of these different subtypes of ion channels have allowed the development of hypotheses on how ion channels transduce a variety of inputs into electrical signals that directly or indirectly regulate gastrointestinal motor activity.

  15. Lunar Smooth Plains Identification and Classification

    NASA Astrophysics Data System (ADS)

    Boyd, A. K.; Robinson, M. S.; Mahanti, P.; Lawrence, S. J.; Spudis, P.; Jolliff, B. L.

    2012-12-01

    Smooth plains are widespread on the Moon and have diverse origins. The maria comprise the majority of the smooth plains and are volcanic in origin. Highland smooth plains are patchy, and tend to fill large craters and basins; their origins have eluded unambiguous classification. Prior to the Apollo 16 mission, many workers thought that highland plains were volcanic, possibly more silicic than the maria. However, as the Apollo 16 samples are mostly impact breccias, the highland smooth plains were re-interpreted basin impact ejecta, most likely from the Imbrium and possibly Orientale basins. Conversely, some known non-mare volcanic units, such as the Apennine Bench Formation, contain light plains. These interpretations do not rule out alternate origins for a subset of highland smooth plains, including impact melt or volcanic origins (effusive or pyroclastic). We developed an algorithm to identify smooth plains using topographic parameters from the WAC Global Lunar Digital Terrain Model (DTM) (GLD100), sampled at 333 m/pixel. We classify the smooth plains using the Clementine UVVIS FeO map and photometrically corrected Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) images. Terrain with slopes less than 2° (1 km baseline) and standard deviation of slope less than 0.75° (1 km x 1 km box, n=9) are defined as smooth plains. Highland smooth plains are distinguished from basaltic smooth plains using the following criteria: LROC WAC 643 nm normalized reflectance > 0.056, LROC WAC 321 nm / 415 nm ratio < 0.74, and Clementine FeO < 12 wt.% (excluding Clementine non-coverage areas). The remaining smooth plains are classified as maria and are subdivided into two classes: LROC WAC 321 nm / 415 nm ratio > 0.77 is termed blue maria and a ratio ≤ 0.77 is termed red maria. The automatic classification was limited to the 87% of the Moon covered by photometrically normalized WAC data (60°S to 60°N). The differences between the maria and highland smooth plains

  16. Synthetic smooth muscle in the outer blood plexus of the rhinarium skin of Lemur catta L.

    PubMed Central

    Elofsson, Rolf; Kröger, Ronald H H

    2017-01-01

    The skin of the lemur nose tip (rhinarium) has arterioles in the outer vascular plexus that are endowed with an unusual coat of smooth muscle cells. Comparison with the arterioles of the same area in a number of unrelated mammalians shows that the lemur pattern is unique. The vascular smooth muscle cells belong to the synthetic type. The function of synthetic smooth muscles around the terminal vessels in the lemur rhinarium is unclear but may have additional functions beyond regulation of vessel diameter. PMID:28260706

  17. Vascular Calcification: Mechanisms of Vascular Smooth Muscle Cell Calcification

    PubMed Central

    Leopold, Jane A.

    2014-01-01

    Vascular calcification is highly prevalent and, when present, is associated with major adverse cardiovascular events. Vascular smooth muscle cells play an integral role in mediating vessel calcification by undergoing differentiation to osteoblast-like cells and generating matrix vesicles that serve as a nidus for calcium-phosphate deposition in the vessel wall. Once believed to be a passive process, it is now recognized that vascular calcification is a complex and highly regulated process that involves activation of cellular signaling pathways, circulating inhibitors of calcification, genetic factors, and hormones. This review will examine several of the key mechanisms linking vascular smooth muscle cells to vessel calcification that may be targeted to reduce vessel wall mineralization and, thereby, reduce cardiovascular risk. PMID:25435520

  18. SMACK - SMOOTHING FOR AIRCRAFT KINEMATICS

    NASA Technical Reports Server (NTRS)

    Bach, R.

    1994-01-01

    The computer program SMACK (SMoothing for AirCraft Kinematics) is designed to provide flightpath reconstruction of aircraft forces and motions from measurements that are noisy or incomplete. Additionally, SMACK provides a check on instrument accuracy and data consistency. The program can be used to analyze data from flight-test experiments prior to their use in performance, stability and control, or aerodynamic modeling calculations. It can also be used in the analysis of aircraft accidents, where the actual forces and motions may have to be determined from a very limited data set. Application of a state-estimation method for flightpath reconstruction is possible because aircraft forces and motions are related by well-known equations of motion. The task of postflight state estimation is known as a nonlinear, fixed-interval smoothing problem. SMACK utilizes a backward-filter, forward-smoother algorithm to solve the problem. The equations of motion are used to produce estimates that are compared with their corresponding measurement time histories. The procedure is iterative, providing improved state estimates until a minimum squared-error measure is achieved. In the SMACK program, the state and measurement models together represent a finite-difference approximation for the six-degree-of-freedom dynamics of a rigid body. The models are used to generate time histories which are likely to be found in a flight-test measurement set. These include onboard variables such as Euler angles, angular rates, and linear accelerations as well as tracking variables such as slant range, bearing, and elevation. Any bias or scale-factor errors associated with the state or measurement models are appended to the state vector and treated as constant but unknown parameters. The SMACK documentation covers the derivation of the solution algorithm, describes the state and measurement models, and presents several application examples that should help the analyst recognize the potential

  19. MicroRNAs dynamically remodel gastrointestinal smooth muscle cells.

    PubMed

    Park, Chanjae; Yan, Wei; Ward, Sean M; Hwang, Sung Jin; Wu, Qiuxia; Hatton, William J; Park, Jong Kun; Sanders, Kenton M; Ro, Seungil

    2011-04-14

    Smooth muscle cells (SMCs) express a unique set of microRNAs (miRNAs) which regulate and maintain the differentiation state of SMCs. The goal of this study was to investigate the role of miRNAs during the development of gastrointestinal (GI) SMCs in a transgenic animal model. We generated SMC-specific Dicer null animals that express the reporter, green fluorescence protein, in a SMC-specific manner. SMC-specific knockout of Dicer prevented SMC miRNA biogenesis, causing dramatic changes in phenotype, function, and global gene expression in SMCs: the mutant mice developed severe dilation of the intestinal tract associated with the thinning and destruction of the smooth muscle (SM) layers; contractile motility in the mutant intestine was dramatically decreased; and SM contractile genes and transcriptional regulators were extensively down-regulated in the mutant SMCs. Profiling and bioinformatic analyses showed that SMC phenotype is regulated by a complex network of positive and negative feedback by SMC miRNAs, serum response factor (SRF), and other transcriptional factors. Taken together, our data suggest that SMC miRNAs are required for the development and survival of SMCs in the GI tract.

  20. Spline-Based Smoothing of Airfoil Curvatures

    NASA Technical Reports Server (NTRS)

    Li, W.; Krist, S.

    2008-01-01

    Constrained fitting for airfoil curvature smoothing (CFACS) is a splinebased method of interpolating airfoil surface coordinates (and, concomitantly, airfoil thicknesses) between specified discrete design points so as to obtain smoothing of surface-curvature profiles in addition to basic smoothing of surfaces. CFACS was developed in recognition of the fact that the performance of a transonic airfoil is directly related to both the curvature profile and the smoothness of the airfoil surface. Older methods of interpolation of airfoil surfaces involve various compromises between smoothing of surfaces and exact fitting of surfaces to specified discrete design points. While some of the older methods take curvature profiles into account, they nevertheless sometimes yield unfavorable results, including curvature oscillations near end points and substantial deviations from desired leading-edge shapes. In CFACS as in most of the older methods, one seeks a compromise between smoothing and exact fitting. Unlike in the older methods, the airfoil surface is modified as little as possible from its original specified form and, instead, is smoothed in such a way that the curvature profile becomes a smooth fit of the curvature profile of the original airfoil specification. CFACS involves a combination of rigorous mathematical modeling and knowledge-based heuristics. Rigorous mathematical formulation provides assurance of removal of undesirable curvature oscillations with minimum modification of the airfoil geometry. Knowledge-based heuristics bridge the gap between theory and designers best practices. In CFACS, one of the measures of the deviation of an airfoil surface from smoothness is the sum of squares of the jumps in the third derivatives of a cubicspline interpolation of the airfoil data. This measure is incorporated into a formulation for minimizing an overall deviation- from-smoothness measure of the airfoil data within a specified fitting error tolerance. CFACS has been

  1. AFSMO/AFSCL- AIRFOIL SMOOTHING AND SCALING

    NASA Technical Reports Server (NTRS)

    Morgan, H. L

    1994-01-01

    Since its early beginnings, NASA has been actively involved in the design and testing of airfoil sections for a wide variety of applications. Recently a set of programs has been developed to smooth and scale arbitrary airfoil coordinates. The smoothing program, AFSMO, utilizes both least-squares polynomial and least-squares cubic-spline techniques to iteratively smooth the second derivatives of the y-axis airfoil coordinates with respect to a transformed x-axis system which unwraps the airfoil and stretches the nose and trailing-edge regions. The corresponding smooth airfoil coordinates are then determined by solving a tridiagonal matrix of simultaneous cubic-spline equations relating the y-axis coordinates and their corresponding second derivatives. The camber and thickness distribution of the smooth airfoil are also computed. The scaling program, AFSCL, may then be used to scale the thickness distribution generated by the smoothing program to a specified maximum thickness. Once the thickness distribution has been scaled, it is combined with the camber distribution to obtain the final scaled airfoil contour. The airfoil smoothing and scaling programs are written in FORTRAN IV for batch execution and have been implemented on a CDC CYBER 170 series computer with a central memory requirement of approximately 70K (octal) of 60 bit words. Both programs generate plotted output via CALCOMP type plotting calls. These programs were developed in 1983.

  2. Numerical Convergence In Smoothed Particle Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Zhu, Qirong; Hernquist, Lars; Li, Yuexing

    2015-02-01

    We study the convergence properties of smoothed particle hydrodynamics (SPH) using numerical tests and simple analytic considerations. Our analysis shows that formal numerical convergence is possible in SPH only in the joint limit N → ∞, h → 0, and Nnb → ∞, where N is the total number of particles, h is the smoothing length, and Nnb is the number of neighbor particles within the smoothing volume used to compute smoothed estimates. Previous work has generally assumed that the conditions N → ∞ and h → 0 are sufficient to achieve convergence, while holding Nnb fixed. We demonstrate that if Nnb is held fixed as the resolution is increased, there will be a residual source of error that does not vanish as N → ∞ and h → 0. Formal numerical convergence in SPH is possible only if Nnb is increased systematically as the resolution is improved. Using analytic arguments, we derive an optimal compromise scaling for Nnb by requiring that this source of error balance that present in the smoothing procedure. For typical choices of the smoothing kernel, we find Nnb vpropN 0.5. This means that if SPH is to be used as a numerically convergent method, the required computational cost does not scale with particle number as O(N), but rather as O(N 1 + δ), where δ ≈ 0.5, with a weak dependence on the form of the smoothing kernel.

  3. Approximation of Bivariate Functions via Smooth Extensions

    PubMed Central

    Zhang, Zhihua

    2014-01-01

    For a smooth bivariate function defined on a general domain with arbitrary shape, it is difficult to do Fourier approximation or wavelet approximation. In order to solve these problems, in this paper, we give an extension of the bivariate function on a general domain with arbitrary shape to a smooth, periodic function in the whole space or to a smooth, compactly supported function in the whole space. These smooth extensions have simple and clear representations which are determined by this bivariate function and some polynomials. After that, we expand the smooth, periodic function into a Fourier series or a periodic wavelet series or we expand the smooth, compactly supported function into a wavelet series. Since our extensions are smooth, the obtained Fourier coefficients or wavelet coefficients decay very fast. Since our extension tools are polynomials, the moment theorem shows that a lot of wavelet coefficients vanish. From this, with the help of well-known approximation theorems, using our extension methods, the Fourier approximation and the wavelet approximation of the bivariate function on the general domain with small error are obtained. PMID:24683316

  4. Progress in smooth particle hydrodynamics

    SciTech Connect

    Wingate, C.A.; Dilts, G.A.; Mandell, D.A.; Crotzer, L.A.; Knapp, C.E.

    1998-07-01

    Smooth Particle Hydrodynamics (SPH) is a meshless, Lagrangian numerical method for hydrodynamics calculations where calculational elements are fuzzy particles which move according to the hydrodynamic equations of motion. Each particle carries local values of density, temperature, pressure and other hydrodynamic parameters. A major advantage of SPH is that it is meshless, thus large deformation calculations can be easily done with no connectivity complications. Interface positions are known and there are no problems with advecting quantities through a mesh that typical Eulerian codes have. These underlying SPH features make fracture physics easy and natural and in fact, much of the applications work revolves around simulating fracture. Debris particles from impacts can be easily transported across large voids with SPH. While SPH has considerable promise, there are some problems inherent in the technique that have so far limited its usefulness. The most serious problem is the well known instability in tension leading to particle clumping and numerical fracture. Another problem is that the SPH interpolation is only correct when particles are uniformly spaced a half particle apart leading to incorrect strain rates, accelerations and other quantities for general particle distributions. SPH calculations are also sensitive to particle locations. The standard artificial viscosity treatment in SPH leads to spurious viscosity in shear flows. This paper will demonstrate solutions for these problems that they and others have been developing. The most promising is to replace the SPH interpolant with the moving least squares (MLS) interpolant invented by Lancaster and Salkauskas in 1981. SPH and MLS are closely related with MLS being essentially SPH with corrected particle volumes. When formulated correctly, JLS is conservative, stable in both compression and tension, does not have the SPH boundary problems and is not sensitive to particle placement. The other approach to

  5. Nonequilibrium Flows with Smooth Particle Applied Mechanics.

    NASA Astrophysics Data System (ADS)

    Kum, Oyeon

    Smooth particle methods are relatively new methods for simulating solid and fluid flows though they have a 20-year history of solving complex hydrodynamic problems in astrophysics, such as colliding planets and stars, for which correct answers are unknown. The results presented in this thesis evaluate the adaptability or fitness of the method for typical hydrocode production problems. For finite hydrodynamic systems, boundary conditions are important. A reflective boundary condition with image particles is a good way to prevent a density anomaly at the boundary and to keep the fluxes continuous there. Boundary values of temperature and velocity can be separately controlled. The gradient algorithm, based on differentiating the smooth particle expressions for (urho) and (Trho), does not show numerical instabilities for the stress tensor and heat flux vector quantities which require second derivatives in space when Fourier's heat -flow law and Newton's viscous force law are used. Smooth particle methods show an interesting parallel linking them to molecular dynamics. For the inviscid Euler equation, with an isentropic ideal gas equation of state, the smooth particle algorithm generates trajectories isomorphic to those generated by molecular dynamics. The shear moduli were evaluated based on molecular dynamics calculations for the three weighting functions, B spline, Lucy, and Cusp functions. The accuracy and applicability of the methods were estimated by comparing a set of smooth particle Rayleigh -Benard problems, all in the laminar regime, to corresponding highly-accurate grid-based numerical solutions of continuum equations. Both transient and stationary smooth particle solutions reproduce the grid-based data with velocity errors on the order of 5%. The smooth particle method still provides robust solutions at high Rayleigh number where grid-based methods fails. Considerably fewer smooth particles are required than atoms in a corresponding molecular dynamics

  6. Smoothing analysis of HLSII storage ring magnets

    NASA Astrophysics Data System (ADS)

    Wang, Wei; He, Xiao-Ye; Tang, Zheng; Yao, Qiu-Yang

    2016-12-01

    Hefei Light Source (HLS) has been upgraded to improve the quality and stability of the synchrotron light, and the new facility is named HLSII. However, a final accurate adjustment is required to smooth the beam orbit after the initial instalment and alignment of the magnets. We implement a reliable smoothing method for the beam orbit of the HLSII storage ring. In addition to greatly smoothing and stabilizing the beam orbit, this method also doubles the work efficiency and significantly reduces the number of magnets adjusted and the range of the adjustments. Supported by National Natural Science Foundation of China (11275192) and the Upgrade Project of Hefei Light Source

  7. Smoothing spline primordial power spectrum reconstruction

    SciTech Connect

    Sealfon, Carolyn; Verde, Licia; Jimenez, Raul

    2005-11-15

    We reconstruct the shape of the primordial power spectrum (PPS) using a smoothing spline. Our adapted smoothing spline technique provides a complementary method to existing efforts to search for smooth features in the PPS, such as a running spectral index. With this technique we find no significant indication with Wilkinson Microwave Anisotropy Probe first-year data that the PPS deviates from a Harrison-Zeldovich spectrum and no evidence for loss of power on large scales. We also examine the effect on the cosmological parameters of the additional PPS freedom. Smooth variations in the PPS are not significantly degenerate with other cosmological parameters, but the spline reconstruction greatly increases the errors on the optical depth and baryon fraction.

  8. 7 CFR 51.768 - Smooth texture.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the skin is thin and smooth for the variety and size of the fruit. “Thin” means that the skin thickness does not average more than 3/8 inch (9.5 mm), on a central cross section, on grapefruit 41/8... 7 Agriculture 2 2012-01-01 2012-01-01 false Smooth texture. 51.768 Section 51.768...

  9. 7 CFR 51.768 - Smooth texture.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the skin is thin and smooth for the variety and size of the fruit. “Thin” means that the skin thickness does not average more than 3/8 inch (9.5 mm), on a central cross section, on grapefruit 41/8... 7 Agriculture 2 2010-01-01 2010-01-01 false Smooth texture. 51.768 Section 51.768...

  10. 7 CFR 51.768 - Smooth texture.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the skin is thin and smooth for the variety and size of the fruit. “Thin” means that the skin thickness does not average more than 3/8 inch (9.5 mm), on a central cross section, on grapefruit 41/8... 7 Agriculture 2 2011-01-01 2011-01-01 false Smooth texture. 51.768 Section 51.768...

  11. A 3D Contact Smoothing Method

    SciTech Connect

    Puso, M A; Laursen, T A

    2002-05-02

    Smoothing of contact surfaces can be used to eliminate the chatter typically seen with node on facet contact and give a better representation of the actual contact surface. The latter affect is well demonstrated for problems with interference fits. In this work we present two methods for the smoothing of contact surfaces for 3D finite element contact. In the first method, we employ Gregory patches to smooth the faceted surface in a node on facet implementation. In the second method, we employ a Bezier interpolation of the faceted surface in a mortar method implementation of contact. As is well known, node on facet approaches can exhibit locking due to the failure of the Babuska-Brezzi condition and in some instances fail the patch test. The mortar method implementation is stable and provides optimal convergence in the energy of error. In the this work we demonstrate the superiority of the smoothed versus the non-smoothed node on facet implementations. We also show where the node on facet method fails and some results from the smoothed mortar method implementation.

  12. Beam-smoothing investigation on Heaven I

    NASA Astrophysics Data System (ADS)

    Xiang, Yi-huai; Gao, Zhi-xing; Tong, Xiao-hui; Dai, Hui; Tang, Xiu-zhang; Shan, Yu-sheng

    2007-01-01

    Directly driven targets for inertial confinement fusion (ICF) require laser beams with extremely smooth irradiance profiles to prevent hydrodynamic instabilities that destroy the spherical symmetry of the target during implosion. Such instabilities can break up and mix together the target's wall and fuel material, preventing it from reaching the density and temperature required for fusion ignition. 1,2 Measurements in the equation of state (EOS) experiments require laser beams with flat-roofed profiles to generate uniform shockwave 3. Some method for beam smooth, is thus needed. A technique called echelon-free induced spatial incoherence (EFISI) is proposed for producing smooth target beam profiles with large KrF lasers. The idea is basically an image projection technique that projects the desired time-averaged spatial profile onto the target via the laser system, using partially coherent broadband lighe. Utilize the technique, we developing beam- smoothing investigation on "Heaven I". At China Institute of Atomic Energy , a new angular multiplexing providing with beam-smoothing function has been developed, the total energy is 158J, the stability of energy is 4%, the pulse duration is 25ns, the effective diameter of focusing spot is 400um, and the ununiformity is about 1.6%, the power density on the target is about 3.7×10 12W/cm2. At present, the system have provided steady and smooth laser irradiation for EOS experiments.

  13. Adaptive quantization-parameter clip scheme for smooth quality in H.264/AVC.

    PubMed

    Hu, Sudeng; Wang, Hanli; Kwong, Sam

    2012-04-01

    In this paper, we investigate the issues over the smooth quality and the smooth bit rate during rate control (RC) in H.264/AVC. An adaptive quantization-parameter (Q(p)) clip scheme is proposed to optimize the quality smoothness while keeping the bit-rate fluctuation at an acceptable level. First, the frame complexity variation is studied by defining a complexity ratio between two nearby frames. Second, the range of the generated bits is analyzed to prevent the encoder buffer from overflow and underflow. Third, based on the safe range of the generated bits, an optimal Q(p) clip range is developed to reduce the quality fluctuation. Experimental results demonstrate that the proposed Q(p) clip scheme can achieve excellent performance in quality smoothness and buffer regulation.

  14. Nonequilibrium flows with smooth particle applied mechanics

    SciTech Connect

    Kum, Oyeon

    1995-07-01

    Smooth particle methods are relatively new methods for simulating solid and fluid flows through they have a 20-year history of solving complex hydrodynamic problems in astrophysics, such as colliding planets and stars, for which correct answers are unknown. The results presented in this thesis evaluate the adaptability or fitness of the method for typical hydrocode production problems. For finite hydrodynamic systems, boundary conditions are important. A reflective boundary condition with image particles is a good way to prevent a density anomaly at the boundary and to keep the fluxes continuous there. Boundary values of temperature and velocity can be separately controlled. The gradient algorithm, based on differentiating the smooth particle expression for (uρ) and (Tρ), does not show numerical instabilities for the stress tensor and heat flux vector quantities which require second derivatives in space when Fourier`s heat-flow law and Newton`s viscous force law are used. Smooth particle methods show an interesting parallel linking to them to molecular dynamics. For the inviscid Euler equation, with an isentropic ideal gas equation of state, the smooth particle algorithm generates trajectories isomorphic to those generated by molecular dynamics. The shear moduli were evaluated based on molecular dynamics calculations for the three weighting functions, B spline, Lucy, and Cusp functions. The accuracy and applicability of the methods were estimated by comparing a set of smooth particle Rayleigh-Benard problems, all in the laminar regime, to corresponding highly-accurate grid-based numerical solutions of continuum equations. Both transient and stationary smooth particle solutions reproduce the grid-based data with velocity errors on the order of 5%. The smooth particle method still provides robust solutions at high Rayleigh number where grid-based methods fails.

  15. Effects of hydrogen sulphide in smooth muscle.

    PubMed

    Dunn, William R; Alexander, Stephen P H; Ralevic, Vera; Roberts, Richard E

    2016-02-01

    In recent years, it has become apparent that the gaseous pollutant, hydrogen sulphide (H2S) can be synthesised in the body and has a multitude of biological actions. This review summarizes some of the actions of this 'gasotransmitter' in influencing the smooth muscle that is responsible for controlling muscular activity of hollow organs. In the vasculature, while H2S can cause vasoconstriction by complex interactions with other biologically important gases, such as nitric oxide, the prevailing response is vasorelaxation. While most vasorelaxation responses occur by a direct action of H2S on smooth muscle cells, it has recently been proposed to be an endothelium-derived hyperpolarizing factor. H2S also promotes relaxation in other smooth muscle preparations including bronchioles, the bladder, gastrointestinal tract and myometrium, opening up the opportunity of exploiting the pharmacology of H2S in the treatment of conditions where smooth muscle tone is excessive. The original concept, that H2S caused smooth muscle relaxation by activating ATP-sensitive K(+) channels, has been supplemented with observations that H2S can also modify the activity of other potassium channels, intracellular pH, phosphodiesterase activity and transient receptor potential channels on sensory nerves. While the enzymes responsible for generating endogenous H2S are widely expressed in smooth muscle preparations, it is much less clear what the physiological role of H2S is in determining smooth muscle contractility. Clarification of this requires the development of potent and selective inhibitors of H2S-generating enzymes.

  16. NUMERICAL CONVERGENCE IN SMOOTHED PARTICLE HYDRODYNAMICS

    SciTech Connect

    Zhu, Qirong; Li, Yuexing; Hernquist, Lars

    2015-02-10

    We study the convergence properties of smoothed particle hydrodynamics (SPH) using numerical tests and simple analytic considerations. Our analysis shows that formal numerical convergence is possible in SPH only in the joint limit N → ∞, h → 0, and N{sub nb} → ∞, where N is the total number of particles, h is the smoothing length, and N{sub nb} is the number of neighbor particles within the smoothing volume used to compute smoothed estimates. Previous work has generally assumed that the conditions N → ∞ and h → 0 are sufficient to achieve convergence, while holding N{sub nb} fixed. We demonstrate that if N{sub nb} is held fixed as the resolution is increased, there will be a residual source of error that does not vanish as N → ∞ and h → 0. Formal numerical convergence in SPH is possible only if N{sub nb} is increased systematically as the resolution is improved. Using analytic arguments, we derive an optimal compromise scaling for N{sub nb} by requiring that this source of error balance that present in the smoothing procedure. For typical choices of the smoothing kernel, we find N{sub nb} ∝N {sup 0.5}. This means that if SPH is to be used as a numerically convergent method, the required computational cost does not scale with particle number as O(N), but rather as O(N {sup 1} {sup +} {sup δ}), where δ ≈ 0.5, with a weak dependence on the form of the smoothing kernel.

  17. Isolation of Endothelial Cells and Vascular Smooth Muscle Cells from Internal Mammary Artery Tissue

    PubMed Central

    Moss, Stephanie C.; Bates, Michael; Parrino, Patrick E.; Woods, T. Cooper

    2007-01-01

    Analyses of vascular smooth muscle cell and endothelial cell function through tissue culture techniques are often employed to investigate the underlying mechanisms regulating cardiovascular disease. As diseases such as diabetes mellitus and chronic kidney disease increase a patient's risk of cardiovascular disease, the development of methods for examining the effects of these diseases on vascular smooth muscle cells and endothelial cells is needed. Commercial sources of endothelial cells and vascular smooth muscle cells generally provide minimal donor information and are in limited supply. This study was designed to determine if vascular smooth muscle cells and endothelial cells could be isolated from human internal mammary arteries obtained from donors undergoing coronary artery bypass graft surgery. As coronary artery bypass graft surgery is a commonly performed procedure, this method would provide a new source for these cells that when combined with the donor's medical history will greatly enhance our studies of the effects of complicating diseases on vascular biology. Internal mammary artery tissue was obtained from patients undergoing coronary artery bypass graft surgery. Through a simple method employing two separate tissue digestions, vascular smooth muscle cells and endothelial cells were isolated and characterized. The isolated vascular smooth muscle cells and endothelial cells exhibited the expected morphology and were able to be passaged for further analysis. The vascular smooth muscle cells exhibited positive staining for α-smooth muscle actin and the endothelial cells exhibited positive staining for CD31. The overall purity of the isolations was > 95%. This method allows for the isolation of endothelial cells and vascular smooth muscle cells from internal mammary arteries, providing a new tool for investigations into the interplay of vascular diseases and complicating diseases such as diabetes and kidney disease. PMID:21603530

  18. Manual tracking enhances smooth pursuit eye movements

    PubMed Central

    Niehorster, Diederick C.; Siu, Wilfred W. F.; Li, Li

    2015-01-01

    Previous studies have reported that concurrent manual tracking enhances smooth pursuit eye movements only when tracking a self-driven or a predictable moving target. Here, we used a control-theoretic approach to examine whether concurrent manual tracking enhances smooth pursuit of an unpredictable moving target. In the eye-hand tracking condition, participants used their eyes to track a Gaussian target that moved randomly along a horizontal axis. In the meantime, they used their dominant hand to move a mouse to control the horizontal movement of a Gaussian cursor to vertically align it with the target. In the eye-alone tracking condition, the target and cursor positions recorded in the eye-hand tracking condition were replayed, and participants only performed eye tracking of the target. Catch-up saccades were identified and removed from the recorded eye movements, allowing for a frequency-response analysis of the smooth pursuit response to unpredictable target motion. We found that the overall smooth pursuit gain was higher and the number of catch-up saccades made was less when eye tracking was accompanied by manual tracking than when not. We conclude that concurrent manual tracking enhances smooth pursuit. This enhancement is a fundamental property of eye-hand coordination that occurs regardless of the predictability of the target motion. PMID:26605840

  19. Smooth muscle archvillin is an ERK scaffolding protein.

    PubMed

    Gangopadhyay, Samudra S; Kengni, Edouard; Appel, Sarah; Gallant, Cynthia; Kim, Hak Rim; Leavis, Paul; DeGnore, Jon; Morgan, Kathleen G

    2009-06-26

    ERK influences a number of pathways in all cells, but how ERK activities are segregated between different pathways has not been entirely clear. Using immunoprecipitation and pulldown experiments with domain-specific recombinant fragments, we show that smooth muscle archvillin (SmAV) binds ERK and members of the ERK signaling cascade in a domain-specific, stimulus-dependent, and pathway-specific manner. MEK binds specifically to the first 445 residues of SmAV. B-Raf, an upstream regulator of MEK, constitutively interacts with residues 1-445 and 446-1250. Both ERK and 14-3-3 bind to both fragments, but in a stimulus-specific manner. Phosphorylated ERK is associated only with residues 1-445. An ERK phosphorylation site was determined by mass spectrometry to reside at Ser132. A phospho-antibody raised to this site shows that the site is phosphorylated during alpha-agonist-mediated ERK activation in smooth muscle tissue. Phosphorylation of SmAV by ERK decreases the association of phospho-ERK with SmAV. These results, combined with previous observations, indicate that SmAV serves as a new ERK scaffolding protein and provide a mechanism for regulation of ERK binding, activation, and release from the signaling complex.

  20. MURC deficiency in smooth muscle attenuates pulmonary hypertension

    PubMed Central

    Nakanishi, Naohiko; Ogata, Takehiro; Naito, Daisuke; Miyagawa, Kotaro; Taniguchi, Takuya; Hamaoka, Tetsuro; Maruyama, Naoki; Kasahara, Takeru; Nishi, Masahiro; Matoba, Satoaki; Ueyama, Tomomi

    2016-01-01

    Emerging evidence suggests that caveolin-1 (Cav1) is associated with pulmonary arterial hypertension. MURC (also called Cavin-4) is a member of the cavin family, which regulates caveolar formation and functions together with caveolins. Here, we show that hypoxia increased Murc mRNA expression in the mouse lung, and that Murc-null mice exhibited attenuation of hypoxia-induced pulmonary hypertension (PH) accompanied by reduced ROCK activity in the lung. Conditional knockout mice lacking Murc in smooth muscle also resist hypoxia-induced PH. MURC regulates the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) through Rho/ROCK signalling. Cav1 suppresses RhoA activity in PASMCs, which is reversed by MURC. MURC binds to Cav1 and inhibits the association of Cav1 with the active form of Gα13, resulting in the facilitated association of the active form of Gα13 with p115RhoGEF. These results reveal that MURC has a function in the development of PH through modulating Rho/ROCK signalling. PMID:27546070

  1. Structured mesh generation with smoothness controls

    NASA Astrophysics Data System (ADS)

    Zhang, Yaoxin; Jia, Yafei; Wang, Sam S. Y.

    2006-08-01

    In geometrically complex domains, the Ryskin and Leal (RL) orthogonal mesh generation system may cause mesh distortion and overlapping problems when using the weak constraint method with specified boundary point distribution for all boundaries. To resolve these problems, an improved RL system with automatic smoothness control is proposed. In this improved RL system, the automatic smoothness control mechanism is based on five types of smoothness conditions and includes the self-adjustment mechanism and the auto-evaluation mechanism for an empirical parameter. The proposed system is illustrated using several test examples. Several applications to natural domains are also demonstrated. It is shown that the improved RL system is capable of resolving the above problems at little cost of orthogonality.

  2. Archetypal oscillator for smooth and discontinuous dynamics.

    PubMed

    Cao, Qingjie; Wiercigroch, Marian; Pavlovskaia, Ekaterina E; Grebogi, Celso; Thompson, J Michael T

    2006-10-01

    We propose an archetypal system to investigate transitions from smooth to discontinuous dynamics. In the smooth regime, the system bears significant similarities to the Duffing oscillator, exhibiting the standard dynamics governed by the hyperbolic structure associated with the stationary state of the double well. At the discontinuous limit, however, there is a substantial departure in the dynamics from the standard one. In particular, the velocity flow suffers a jump in crossing from one well to another, caused by the loss of local hyperbolicity due to the collapse of the stable and unstable manifolds of the stationary state. In the presence of damping and external excitation, the system has coexisting attractors and also a chaotic saddle which becomes a chaotic attractor when a smoothness parameter drops to zero. This attractor can bifurcate to a high-period periodic attractor or a chaotic sea with islands of quasiperiodic attractors depending on the strength of damping.

  3. Multiple predictor smoothing methods for sensitivity analysis.

    SciTech Connect

    Helton, Jon Craig; Storlie, Curtis B.

    2006-08-01

    The use of multiple predictor smoothing methods in sampling-based sensitivity analyses of complex models is investigated. Specifically, sensitivity analysis procedures based on smoothing methods employing the stepwise application of the following nonparametric regression techniques are described: (1) locally weighted regression (LOESS), (2) additive models, (3) projection pursuit regression, and (4) recursive partitioning regression. The indicated procedures are illustrated with both simple test problems and results from a performance assessment for a radioactive waste disposal facility (i.e., the Waste Isolation Pilot Plant). As shown by the example illustrations, the use of smoothing procedures based on nonparametric regression techniques can yield more informative sensitivity analysis results than can be obtained with more traditional sensitivity analysis procedures based on linear regression, rank regression or quadratic regression when nonlinear relationships between model inputs and model predictions are present.

  4. ibr: Iterative bias reduction multivariate smoothing

    SciTech Connect

    Hengartner, Nicholas W; Cornillon, Pierre-andre; Matzner - Lober, Eric

    2009-01-01

    Regression is a fundamental data analysis tool for relating a univariate response variable Y to a multivariate predictor X {element_of} E R{sup d} from the observations (X{sub i}, Y{sub i}), i = 1,...,n. Traditional nonparametric regression use the assumption that the regression function varies smoothly in the independent variable x to locally estimate the conditional expectation m(x) = E[Y|X = x]. The resulting vector of predicted values {cflx Y}{sub i} at the observed covariates X{sub i} is called a regression smoother, or simply a smoother, because the predicted values {cflx Y}{sub i} are less variable than the original observations Y{sub i}. Linear smoothers are linear in the response variable Y and are operationally written as {cflx m} = X{sub {lambda}}Y, where S{sub {lambda}} is a n x n smoothing matrix. The smoothing matrix S{sub {lambda}} typically depends on a tuning parameter which we denote by {lambda}, and that governs the tradeoff between the smoothness of the estimate and the goodness-of-fit of the smoother to the data by controlling the effective size of the local neighborhood over which the responses are averaged. We parameterize the smoothing matrix such that large values of {lambda} are associated to smoothers that averages over larger neighborhood and produce very smooth curves, while small {lambda} are associated to smoothers that average over smaller neighborhood to produce a more wiggly curve that wants to interpolate the data. The parameter {lambda} is the bandwidth for kernel smoother, the span size for running-mean smoother, bin smoother, and the penalty factor {lambda} for spline smoother.

  5. Airway epithelium stimulates smooth muscle proliferation.

    PubMed

    Malavia, Nikita K; Raub, Christopher B; Mahon, Sari B; Brenner, Matthew; Panettieri, Reynold A; George, Steven C

    2009-09-01

    Communication between the airway epithelium and stroma is evident during embryogenesis, and both epithelial shedding and increased smooth muscle proliferation are features of airway remodeling. Hence, we hypothesized that after injury the airway epithelium could modulate airway smooth muscle proliferation. Fully differentiated primary normal human bronchial epithelial (NHBE) cells at an air-liquid interface were co-cultured with serum-deprived normal primary human airway smooth muscle cells (HASM) using commercially available Transwells. In some co-cultures, the NHBE were repeatedly (x4) scrape-injured. An in vivo model of tracheal injury consisted of gently denuding the tracheal epithelium (x3) of a rabbit over 5 days and then examining the trachea by histology 3 days after the last injury. Our results show that HASM cell number increases 2.5-fold in the presence of NHBE, and 4.3-fold in the presence of injured NHBE compared with HASM alone after 8 days of in vitro co-culture. In addition, IL-6, IL-8, monocyte chemotactic protein (MCP)-1 and, more markedly, matrix metalloproteinase (MMP)-9 concentration increased in co-culture correlating with enhanced HASM growth. Inhibiting MMP-9 release significantly attenuated the NHBE-dependent HASM proliferation in co-culture. In vivo, the injured rabbit trachea demonstrated proliferation in the smooth muscle (trachealis) region and significant MMP-9 staining, which was absent in the uninjured control. The airway epithelium modulates smooth muscle cell proliferation via a mechanism that involves secretion of soluble mediators including potential smooth muscle mitogens such as IL-6, IL-8, and MCP-1, but also through a novel MMP-9-dependent mechanism.

  6. Production of super-smooth articles

    SciTech Connect

    Duchane, D.V.

    1983-03-15

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(Methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  7. Geometrical Wake of a Smooth Flat Collimator

    SciTech Connect

    Stupakov, G.V.; /SLAC

    2011-09-09

    A transverse geometrical wake generated by a beam passing through a smooth flat collimator with a gradually varying gap between the upper and lower walls is considered. Based on generalization of the approach recently developed for a smooth circular taper we reduce the electromagnetic problem of the impedance calculation to the solution of two much simpler static problems - a magnetostatic and an electrostatic ones. The solution shows that in the limit of not very large frequencies, the impedance increases with the ratio h/d where h is the width and d is the distance between the collimating jaws. Numerical results are presented for the NLC Post Linac collimator.

  8. Production of super-smooth articles

    DOEpatents

    Duchane, David V.

    1983-01-01

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  9. Production of super-smooth articles

    SciTech Connect

    Duchane, D.V.

    1981-05-29

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  10. Smooth muscle adaptation and recovery of contractility after massive small bowel resection in rats.

    PubMed

    Chen, Jie; Wen, Jie; Cai, Wei

    2012-05-01

    Previous studies have suggested that massive small bowel resection (mSBR) compromises the normal intestinal processes of digestion and absorption, and requires an adaptive response to regain full function and reinstate coordinated contractile activity of the circular smooth muscle. This study was designed to investigate spontaneous contractile activity of circular smooth muscle using the mSBR rat model and to determine the functional role of M(2) and M(3) muscarinic acetylcholine receptors (mAChR) in this process. Male Sprague-Dawley rats underwent an 80% proximal SBR or sham operation. Markers of adaptation, including villus and microvillus height, were analyzed by hematoxylin and eosin staining and transmission electron microscopy. Contractility was measured by attaching the distal ileum strips to strain gauge transducers and exposing the tissue to varying doses of the cholinergic agonist carbachol. Protein expressions of M(2)- and M(3)-mAChR in intestinal smooth muscle (ISM) were detected by Western blot. Following mSBR, the ISM showed perturbed spontaneous rhythmic contraction, irregular amplitude and slow frequency by muscle strip test. However, by two weeks after mSBR, the contractile function of circular smooth muscle was found to have returned to normal levels. Protein expression of M(2)-mAChR was down-regulated following mSBR but up-regulated during the adaptive process when contractile activity of circular smooth muscle was regained. These results indicate that smooth muscle contractility was spontaneously restored in rats following mSBR, and involved the acetylcholine receptors M(2) and M(3). Thus, the disrupted contractile response of smooth muscle in short bowel syndrome may be corrected by therapeutic intervention to restore the expressions of M(2)- and M(3)-mAChR to pre-mSBR levels.

  11. Endothelial and smooth muscle histamine receptors

    SciTech Connect

    Blank, R.S.; Hollis, T.M.

    1986-03-01

    Histamine is produced within the vascular wall and mediates a variety of normal and pathologic vascular responses. The interaction of histamine with its vascular cell receptors has been shown to affect factors such as actin cable formation, cyclase activities, prostacyclin synthesis, cell motility, and proliferation. In addition, abundant evidence exists to implicate an arterial nascent histamine pool in the control of vessel wall permeability under conditions of stress and injury. However, endothelial and smooth muscle cell histamine receptors have been only incompletely characterized. The authors report here the time-dependent, saturable, and trypsin sensitive binding of /sup 3/H-histamine to the endothelial cell surface. The K/sub d/ for endothelial and smooth muscle cell histamine receptors are 0.70 and 2.80 ..mu..M respectively. Histamine binding to smooth muscle cells also exhibited saturation with concentrations of /sup 3/H-histamine up to 4 ..mu..M. While the smooth muscle cell H/sub 1/ receptor binding was negligible, the H/sub 2/ receptor appeared to represent a relatively low affinity, high capacity site for histamine binding. The uptake of /sup 3/H-histamine in both cell types displayed kinetics consistent with that of fluid-phase pinocytosis.

  12. Autonomic Modification of Intestinal Smooth Muscle Contractility

    ERIC Educational Resources Information Center

    Montgomery, Laura E. A.; Tansey, Etain A.; Johnson, Chris D.; Roe, Sean M.; Quinn, Joe G.

    2016-01-01

    Intestinal smooth muscle contracts rhythmically in the absence of nerve and hormonal stimulation because of the activity of pacemaker cells between and within the muscle layers. This means that the autonomic nervous system modifies rather than initiates intestinal contractions. The practical described here gives students an opportunity to observe…

  13. Impact modeling with Smooth Particle Hydrodynamics

    SciTech Connect

    Stellingwerf, R.F.; Wingate, C.A.

    1992-01-01

    Smooth Particle Hydrodynamics (SPH) is a new computational technique uniquely suited to computation of hypervelocity impact phenomena. This paper reviews the characteristics, philosophy, and a bit of the derivation of the method. As illustrations of the technique, several test case computations and several application computations are shown.

  14. Impact modeling with Smooth Particle Hydrodynamics

    SciTech Connect

    Stellingwerf, R.F.; Wingate, C.A.

    1992-09-01

    Smooth Particle Hydrodynamics (SPH) is a new computational technique uniquely suited to computation of hypervelocity impact phenomena. This paper reviews the characteristics, philosophy, and a bit of the derivation of the method. As illustrations of the technique, several test case computations and several application computations are shown.

  15. Autonomic modification of intestinal smooth muscle contractility.

    PubMed

    Montgomery, Laura E A; Tansey, Etain A; Johnson, Chris D; Roe, Sean M; Quinn, Joe G

    2016-03-01

    Intestinal smooth muscle contracts rhythmically in the absence of nerve and hormonal stimulation because of the activity of pacemaker cells between and within the muscle layers. This means that the autonomic nervous system modifies rather than initiates intestinal contractions. The practical described here gives students an opportunity to observe this spontaneous activity and its modification by agents associated with parasympathetic and sympathetic nerve activity. A section of the rabbit small intestine is suspended in an organ bath, and the use of a pressure transducer and data-acquisition software allows the measurement of tension generated by the smooth muscle of intestinal walls. The application of the parasympathetic neurotransmitter ACh at varying concentrations allows students to observe an increase in intestinal smooth muscle tone with increasing concentrations of this muscarinic receptor agonist. Construction of a concentration-effect curve allows students to calculate an EC50 value for ACh and consider some basic concepts surrounding receptor occupancy and activation. Application of the hormone epinephrine to the precontracted intestine allows students to observe the inhibitory effects associated with sympathetic nerve activation. Introduction of the drug atropine to the preparation before a maximal concentration of ACh is applied allows students to observe the inhibitory effect of a competitive antagonist on the physiological response to a receptor agonist. The final experiment involves the observation of the depolarizing effect of K(+) on smooth muscle. Students are also invited to consider why the drugs atropine, codeine, loperamide, and botulinum toxin have medicinal uses in the management of gastrointestinal problems.

  16. Characterization of signaling pathways coupled to melatonin receptors in gastrointestinal smooth muscle.

    PubMed

    Ahmed, Rashad; Mahavadi, Sunila; Al-Shboul, Othman; Bhattacharya, Sayak; Grider, John R; Murthy, Karnam S

    2013-06-10

    Melatonin, a close derivative of serotonin, is involved in physiological regulation of circadian rhythms. In the gastrointestinal (GI) system, melatonin exhibits endocrine, paracrine and autocrine actions and is implicated in the regulation of GI motility. However, it is not known whether melatonin can also act directly on GI smooth muscle cells. The aim of the present study was to determine the expression of melatonin receptors in smooth muscle and identify their signaling pathways. MT1, but not MT2 receptors are expressed in freshly dispersed and cultured gastric smooth muscle cells. Melatonin selectively activated Gq and stimulated phosphoinositide (PI) hydrolysis in freshly dispersed and cultured muscle cells. PI hydrolysis was blocked by the expression of Gq, but not Gi minigene in cultured muscle cells. Melatonin also caused rapid increase in cytosolic Ca(2+) as determined by epifluorescence microscopy in fura-2 loaded single smooth muscle cells, and induced rapid contraction. Melatonin-induced PI hydrolysis and contraction were blocked by a non-selective MT1/MT2 antagonist luzindole (1 μM), but not by a selective MT2 antagonist 4P-PDOT (100 nM), and by the PLC inhibitor U73122. MT2 selective agonist IIK7 (100 nM) had no effect on PI hydrolysis and contraction. We conclude that rabbit gastric smooth muscle cells express melatonin MT1 receptors coupled to Gq. Activation of these receptors causes stimulation of PI hydrolysis and increase in cytosolic Ca(2+), and elicits muscle contraction.

  17. Voltage dependent potassium channel remodeling in murine intestinal smooth muscle hypertrophy induced by partial obstruction.

    PubMed

    Liu, Dong-Hai; Huang, Xu; Guo, Xin; Meng, Xiang-Min; Wu, Yi-Song; Lu, Hong-Li; Zhang, Chun-Mei; Kim, Young-chul; Xu, Wen-Xie

    2014-01-01

    Partial obstruction of the small intestine causes obvious hypertrophy of smooth muscle cells and motility disorder in the bowel proximate to the obstruction. To identify electric remodeling of hypertrophic smooth muscles in partially obstructed murine small intestine, the patch-clamp and intracellular microelectrode recording methods were used to identify the possible electric remodeling and Western blot, immunofluorescence and immunoprecipitation were utilized to examine the channel protein expression and phosphorylation level changes in this research. After 14 days of obstruction, partial obstruction caused obvious smooth muscle hypertrophy in the proximally located intestine. The slow waves of intestinal smooth muscles in the dilated region were significantly suppressed, their amplitude and frequency were reduced, whilst the resting membrane potentials were depolarized compared with normal and sham animals. The current density of voltage dependent potassium channel (KV) was significantly decreased in the hypertrophic smooth muscle cells and the voltage sensitivity of KV activation was altered. The sensitivity of KV currents (IKV) to TEA, a nonselective potassium channel blocker, increased significantly, but the sensitivity of IKv to 4-AP, a KV blocker, stays the same. The protein levels of KV4.3 and KV2.2 were up-regulated in the hypertrophic smooth muscle cell membrane. The serine and threonine phosphorylation levels of KV4.3 and KV2.2 were significantly increased in the hypertrophic smooth muscle cells. Thus this study represents the first identification of KV channel remodeling in murine small intestinal smooth muscle hypertrophy induced by partial obstruction. The enhanced phosphorylations of KV4.3 and KV2.2 may be involved in this process.

  18. Interaction of Vascular Smooth Muscle Cells Under Low Shear Stress

    NASA Technical Reports Server (NTRS)

    Seidel, Charles L.

    1998-01-01

    The blood vessel wall consists of three cellular layers, an outer adventitial, a middle medial and an inner intimal layer. When the blood vessel forms in the embryo it begins as a tube composed of a single cell type called endothelial cells. Over time, other cells are recruited from the surrounding tissue to form additional layers on the outer surface of the endothelial tube. The cells that are recruited are called mesenchymal cells. Mesenchymal cells are responsible for the production of connective tissue that holds the blood vessel together and for developing into vascular smooth muscle cells that are responsible for regulating the diameter of the vessel (1) and therefore, blood flow. In a fully developed blood vessel, the endothelial cells make- up the majority of cells in the intimal layer while the mesenchymal cells make-up the majority of cells in the medial and adventitial layers. Within the medial layer of a mature vessel, cells are organized into multiple circular layers of alternating bands of connective tissue and cells. The cell layer is composed of a mixture of mesenchymal cells that have not developed into smooth muscle cells and fully developed smooth muscle cells (2). The assembly and organization of complex tissues is directed in part by a signaling system composed of proteins on the cell surface called adhesion molecules. Adhesion molecules enable cells to recognize each other as well as the composition of the connective tissue in which they reside (3). It was hypothesized that the different cell types that compose the vascular wall possess different adhesion molecules that enable them to recognize each other and through this recognition system, form the complex layered organization of the vascular wall. In other words, the layered organization is an intrinsic property of the cells. If this hypothesis is correct then the different cells that make up the vessel wall, when mixed together, should organize themselves into a layered structure

  19. The importance of the smooth muscle cytoskeleton to preterm labour.

    PubMed

    Morgan, Kathleen G

    2014-03-01

    Multiple mechanisms have been shown to regulate the onset of labour in a co-operative and complex manner. One factor, myometrial stretch and associated increases in wall tension, has been implicated clinically in the initiation of labour and especially the aetiology of preterm labour. Recent work on the mechanisms involved has led to the finding that the intracellular Ca(2+) requirement for activation of the myometrial contractile filaments increases during gestation. The decreased Ca(2+) sensitivity correlates with an increase in the expression of caldesmon, an actin-binding protein and inhibitor of myosin activation, during pregnancy. In late pregnancy, an increase in extracellular signal-regulated kinase-mediated caldesmon phosphorylation occurs, which appears to reverse the inhibitory action of caldesmon during labour. Force generated by the myometrial contractile filaments is communicated across the plasmalemma to the uterine wall through focal adhesions. Phospho-tyrosine screening and mass spectrometry of stretched myometrial samples identified several stretch-activated focal adhesion proteins. This Src-mediated focal adhesion signalling appears to provide a tunable, i.e. regulated, tension sensor and force transmitter in the myometrial cell. In other parallel studies, biophysical measurements of smooth muscle compliance at both the cellular and tissue levels suggest that decreases in cellular compliance due to changing interactions of the actin cytoskeleton with the focal adhesions may also promote increases in uterine wall tension. These results, taken together, suggest that focal adhesion proteins and their interaction with the cytoskeleton may present a new mode of regulation of uterine contractility.

  20. Thrombospondin-1 limits ischemic tissue survival by inhibiting nitric oxide–mediated vascular smooth muscle relaxation

    PubMed Central

    Isenberg, Jeff S.; Hyodo, Fuminori; Matsumoto, Ken-Ichiro; Romeo, Martin J.; Abu-Asab, Mones; Tsokos, Maria; Kuppusamy, Periannan; Wink, David A.; Krishna, Murali C.

    2007-01-01

    The nitric oxide (NO)/cGMP pathway, by relaxing vascular smooth muscle cells, is a major physiologic regulator of tissue perfusion. We now identify thrombospondin-1 as a potent antagonist of NO for regulating F-actin assembly and myosin light chain phosphorylation in vascular smooth muscle cells. Thrombospondin-1 prevents NO-mediated relaxation of precontracted vascular smooth muscle cells in a collagen matrix. Functional magnetic resonance imaging demonstrated that an NO-mediated increase in skeletal muscle perfusion was enhanced in thrombospondin-1–null relative to wild-type mice, implicating endogenous thrombospondin-1 as a physiologic antagonist of NO-mediated vasodilation. Using a random myocutaneous flap model for ischemic injury, tissue survival was significantly enhanced in thrombospondin-1–null mice. Improved flap survival correlated with increased recovery of oxygen levels in the ischemic tissue of thrombospondin-1–null mice as measured by electron paramagnetic resonance oximetry. These findings demonstrate an important antag-onistic relation between NO/cGMP signaling and thrombospondin-1 in vascular smooth muscle cells to regulate vascular tone and tissue perfusion. PMID:17082319

  1. A Generalized Eigensolver based on Smoothed Aggregation (GES-SA) for Initializing Smoothed Aggregation Multigrid (SA)

    SciTech Connect

    Brezina, M; Manteuffel, T; McCormick, S; Ruge, J; Sanders, G; Vassilevski, P S

    2007-05-31

    Consider the linear system Ax = b, where A is a large, sparse, real, symmetric, and positive definite matrix and b is a known vector. Solving this system for unknown vector x using a smoothed aggregation multigrid (SA) algorithm requires a characterization of the algebraically smooth error, meaning error that is poorly attenuated by the algorithm's relaxation process. For relaxation processes that are typically used in practice, algebraically smooth error corresponds to the near-nullspace of A. Therefore, having a good approximation to a minimal eigenvector is useful to characterize the algebraically smooth error when forming a linear SA solver. This paper discusses the details of a generalized eigensolver based on smoothed aggregation (GES-SA) that is designed to produce an approximation to a minimal eigenvector of A. GES-SA might be very useful as a standalone eigensolver for applications that desire an approximate minimal eigenvector, but the primary aim here is for GES-SA to produce an initial algebraically smooth component that may be used to either create a black-box SA solver or initiate the adaptive SA ({alpha}SA) process.

  2. Magnesium Attenuates Phosphate-Induced Deregulation of a MicroRNA Signature and Prevents Modulation of Smad1 and Osterix during the Course of Vascular Calcification.

    PubMed

    Louvet, Loïc; Metzinger, Laurent; Büchel, Janine; Steppan, Sonja; Massy, Ziad A

    2016-01-01

    Vascular calcification (VC) is prevalent in patients suffering from chronic kidney disease (CKD). High phosphate levels promote VC by inducing abnormalities in mineral and bone metabolism. Previously, we demonstrated that magnesium (Mg(2+)) prevents inorganic phosphate- (Pi-) induced VC in human aortic vascular smooth muscle cells (HAVSMC). As microRNAs (miR) modulate gene expression, we investigated the role of miR-29b, -30b, -125b, -133a, -143, and -204 in the protective effect of Mg(2+) on VC. HAVSMC were cultured in the presence of 3 mM Pi with or without 2 mM Mg(2+) chloride. Total RNA was extracted after 4 h, 24 h, day 3, day 7, and day 10. miR-30b, -133a, and -143 were downregulated during the time course of Pi-induced VC, whereas the addition of Mg(2+) restored (miR-30b) or improved (miR-133a, miR-143) their expression. The expression of specific targets Smad1 and Osterix was significantly increased in the presence of Pi and restored by coincubation with Mg(2+). As miR-30b, miR-133a, and miR-143 are negatively regulated by Pi and restored by Mg(2+) with a congruent modulation of their known targets Runx2, Smad1, and Osterix, our results provide a potential mechanistic explanation of the observed upregulation of these master switches of osteogenesis during the course of VC.

  3. Magnesium Attenuates Phosphate-Induced Deregulation of a MicroRNA Signature and Prevents Modulation of Smad1 and Osterix during the Course of Vascular Calcification

    PubMed Central

    Louvet, Loïc; Metzinger, Laurent; Büchel, Janine; Steppan, Sonja; Massy, Ziad A.

    2016-01-01

    Vascular calcification (VC) is prevalent in patients suffering from chronic kidney disease (CKD). High phosphate levels promote VC by inducing abnormalities in mineral and bone metabolism. Previously, we demonstrated that magnesium (Mg2+) prevents inorganic phosphate- (Pi-) induced VC in human aortic vascular smooth muscle cells (HAVSMC). As microRNAs (miR) modulate gene expression, we investigated the role of miR-29b, -30b, -125b, -133a, -143, and -204 in the protective effect of Mg2+ on VC. HAVSMC were cultured in the presence of 3 mM Pi with or without 2 mM Mg2+ chloride. Total RNA was extracted after 4 h, 24 h, day 3, day 7, and day 10. miR-30b, -133a, and -143 were downregulated during the time course of Pi-induced VC, whereas the addition of Mg2+ restored (miR-30b) or improved (miR-133a, miR-143) their expression. The expression of specific targets Smad1 and Osterix was significantly increased in the presence of Pi and restored by coincubation with Mg2+. As miR-30b, miR-133a, and miR-143 are negatively regulated by Pi and restored by Mg2+ with a congruent modulation of their known targets Runx2, Smad1, and Osterix, our results provide a potential mechanistic explanation of the observed upregulation of these master switches of osteogenesis during the course of VC. PMID:27419135

  4. Molecular memory with atomically smooth graphene contacts

    PubMed Central

    2013-01-01

    We report the use of bilayer graphene as an atomically smooth contact for nanoscale devices. A two-terminal bucky-ball (C60) based molecular memory is fabricated with bilayer graphene as a contact on the polycrystalline nickel electrode. Graphene provides an atomically smooth covering over an otherwise rough metal surface. The use of graphene additionally prohibits the electromigration of nickel into the C60 layer. The devices exhibit a low-resistance state in the first sweep cycle and irreversibly switch to a high-resistance state at 0.8 to 1.2 V bias. In the subsequent cycles, the devices retain the high-resistance state, thus making it write-once read-many memory. PMID:24225345

  5. SPHGR: Smoothed-Particle Hydrodynamics Galaxy Reduction

    NASA Astrophysics Data System (ADS)

    Thompson, Robert

    2015-02-01

    SPHGR (Smoothed-Particle Hydrodynamics Galaxy Reduction) is a python based open-source framework for analyzing smoothed-particle hydrodynamic simulations. Its basic form can run a baryonic group finder to identify galaxies and a halo finder to identify dark matter halos; it can also assign said galaxies to their respective halos, calculate halo & galaxy global properties, and iterate through previous time steps to identify the most-massive progenitors of each halo and galaxy. Data about each individual halo and galaxy is collated and easy to access. SPHGR supports a wide range of simulations types including N-body, full cosmological volumes, and zoom-in runs. Support for multiple SPH code outputs is provided by pyGadgetReader (ascl:1411.001), mainly Gadget (ascl:0003.001) and TIPSY (ascl:1111.015).

  6. Compensating for estimation smoothing in kriging

    USGS Publications Warehouse

    Olea, R.A.; Pawlowsky, Vera

    1996-01-01

    Smoothing is a characteristic inherent to all minimum mean-square-error spatial estimators such as kriging. Cross-validation can be used to detect and model such smoothing. Inversion of the model produces a new estimator-compensated kriging. A numerical comparison based on an exhaustive permeability sampling of a 4-fr2 slab of Berea Sandstone shows that the estimation surface generated by compensated kriging has properties intermediate between those generated by ordinary kriging and stochastic realizations resulting from simulated annealing and sequential Gaussian simulation. The frequency distribution is well reproduced by the compensated kriging surface, which also approximates the experimental semivariogram well - better than ordinary kriging, but not as well as stochastic realizations. Compensated kriging produces surfaces that are more accurate than stochastic realizations, but not as accurate as ordinary kriging. ?? 1996 International Association for Mathematical Geology.

  7. A smoothing algorithm using cubic spline functions

    NASA Technical Reports Server (NTRS)

    Smith, R. E., Jr.; Price, J. M.; Howser, L. M.

    1974-01-01

    Two algorithms are presented for smoothing arbitrary sets of data. They are the explicit variable algorithm and the parametric variable algorithm. The former would be used where large gradients are not encountered because of the smaller amount of calculation required. The latter would be used if the data being smoothed were double valued or experienced large gradients. Both algorithms use a least-squares technique to obtain a cubic spline fit to the data. The advantage of the spline fit is that the first and second derivatives are continuous. This method is best used in an interactive graphics environment so that the junction values for the spline curve can be manipulated to improve the fit.

  8. Generation of Surfaces with Smooth Highlight Lines

    DTIC Science & Technology

    2000-01-01

    2 (s)ds/ si. (2) 0=i i=1 §3. Concept of Surface Generation Based on Evolute A surface is generated by moving a generatrix along two directrices . When...Fig. 1(a) shows an object surface Surfaces with Smooth Highlight Lines 147 Sgeneratrices v generated surface S u directrices evoluteseolesufc (a...the directrices , and suffix u denotes partial differentiation. Fig. 1(b) shows an evolute surface and a generated surface satisfying the constraints

  9. Structure-Preserving Smoothing of Biomedical Images

    NASA Astrophysics Data System (ADS)

    Gil, Debora; Hernàndez-Sabaté, Aura; Burnat, Mireia; Jansen, Steven; Martínez-Villalta, Jordi

    Smoothing of biomedical images should preserve gray-level transitions between adjacent tissues, while restoring contours consistent with anatomical structures. Anisotropic diffusion operators are based on image appearance discontinuities (either local or contextual) and might fail at weak inter-tissue transitions. Meanwhile, the output of block-wise and morphological operations is prone to present a block structure due to the shape and size of the considered pixel neighborhood.

  10. Wrench for smooth or damaged fasteners

    NASA Technical Reports Server (NTRS)

    Carrillo, R.

    1981-01-01

    Smooth-surfaced or damaged fasteners that cannot be gripped by conventional wrench can be unscrewed by special wrench. It can be used in tight spaces and will not damage adjacent structures. Wrench consists of central handle and 2 independent jaws with serrated teeth. Teeth are placed on fastener to be removed, and handle is rotated until fastener is gripped with positive locking action. Rotation of wrench handle removes fastener.

  11. Variational algorithms for nonlinear smoothing applications

    NASA Technical Reports Server (NTRS)

    Bach, R. E., Jr.

    1977-01-01

    A variational approach is presented for solving a nonlinear, fixed-interval smoothing problem with application to offline processing of noisy data for trajectory reconstruction and parameter estimation. The nonlinear problem is solved as a sequence of linear two-point boundary value problems. Second-order convergence properties are demonstrated. Algorithms for both continuous and discrete versions of the problem are given, and example solutions are provided.

  12. Rotorcraft Smoothing Via Linear Time Periodic Methods

    DTIC Science & Technology

    2007-07-01

    Optimal Control Methodology for Rotor Vibration Smoothing . . 30 vii Page IV. Mathematic Foundations of Linear Time Periodic Systems . . . . 33 4.1 The...62 6.3 The Maximum Likelihood Estimator . . . . . . . . . . . 63 6.4 The Cramer-Rao Inequality . . . . . . . . . . . . . . . . 66 6.4.1 Statistical ...adjustments for vibration reduction. 2.2.2.4 1980’s to late 1990’s. Rotor vibrational reduction methods during the 1980’s began to adopt a mathematical

  13. On the thermodynamics of smooth muscle contraction

    NASA Astrophysics Data System (ADS)

    Stålhand, Jonas; McMeeking, Robert M.; Holzapfel, Gerhard A.

    2016-09-01

    Cell function is based on many dynamically complex networks of interacting biochemical reactions. Enzymes may increase the rate of only those reactions that are thermodynamically consistent. In this paper we specifically treat the contraction of smooth muscle cells from the continuum thermodynamics point of view by considering them as an open system where matter passes through the cell membrane. We systematically set up a well-known four-state kinetic model for the cross-bridge interaction of actin and myosin in smooth muscle, where the transition between each state is driven by forward and reverse reactions. Chemical, mechanical and energy balance laws are provided in local forms, while energy balance is also formulated in the more convenient temperature form. We derive the local (non-negative) production of entropy from which we deduce the reduced entropy inequality and the constitutive equations for the first Piola-Kirchhoff stress tensor, the heat flux, the ion and molecular flux and the entropy. One example for smooth muscle contraction is analyzed in more detail in order to provide orientation within the established general thermodynamic framework. In particular the stress evolution, heat generation, muscle shorting rate and a condition for muscle cooling are derived.

  14. Smooth muscle tumours of the alimentary tract.

    PubMed Central

    Diamond, T.; Danton, M. H.; Parks, T. G.

    1990-01-01

    Neoplasms arising from smooth muscle of the gastrointestinal (GI) tract are uncommon, comprising only 1% of gastrointestinal tumours. A total of 51 cases of smooth muscle tumour of the GI tract were analysed; 44 leiomyomas and 7 leiomyosarcomas. Lesions occurred in all areas from the oesophagus to the rectum, the stomach being the commonest site. Thirty-six patients had clinical features referable to the tumour. The tumour was detected during investigation or management of an unrelated disease process in 15 patients. The clinical presentation varied depending on tumour location, but abdominal pain and GI bleeding were the commonest presenting symptoms. The lesion was demonstrated preoperatively, mainly by endoscopy and barium studies, in 27 patients. Surgical excision was the treatment of choice, where possible. There was no recurrence in the leiomyoma group but four patients died in the leiomyosarcoma group. Although rare, smooth muscle tumours should be considered in situations where clinical presentation and investigations are not suggestive of any common GI disorder. The preoperative assessment and diagnosis is difficult because of the variability in clinical features and their inaccessibility to routine GI investigation. It is recommended that, where possible, the lesion, whether symptomatic or discovered incidentally, should be excised completely to achieve a cure and prevent future complications. Images Figure 3 Figure 4 PMID:2221768

  15. Smooth muscle differentiation in scleroderma fibroblastic cells.

    PubMed Central

    Sappino, A. P.; Masouyé, I.; Saurat, J. H.; Gabbiani, G.

    1990-01-01

    Using antibodies to alpha-smooth muscle actin and desmin on paraffin-embedded formalin-fixed tissue sections, the authors demonstrate that fibroblastic cells of localized and systemic scleroderma lesions express features of smooth muscle differentiation. Eleven of eleven skin specimens of systemic sclerosis patients and two of four skin specimens of localized scleroderma displayed the presence of fibroblasts expressing alpha-smooth muscle actin, a cell population that predominated in areas of prominent collagen deposition. A similar fibroblastic phenotype was found in the esophagus, the liver, and the lung specimens obtained from four patients who died of progressive systemic sclerosis. Immunostaining for desmin, performed on adjacent tissue sections, demonstrated that a minority of these fibroblastic cells present in skin and visceral lesions contained this protein. The authors' observations indicate that scleroderma fibroblasts are phenotypically related to the stromal cells previously identified in hypertrophic scars, fibromatoses, and desmoplasia; they might provide novel criteria for the characterization of scleroderma lesions and help to identify the factors responsible for phenotypic modulations in fibroblastic cells. Images Figure 1 Figure 2 Figure 3 PMID:1698026

  16. Symmetric smoothing filters from global consistency constraints.

    PubMed

    Haque, Sheikh Mohammadul; Pai, Gautam P; Govindu, Venu Madhav

    2015-05-01

    Many patch-based image denoising methods can be viewed as data-dependent smoothing filters that carry out a weighted averaging of similar pixels. It has recently been argued that these averaging filters can be improved using their doubly stochastic approximation, which are symmetric and stable smoothing operators. In this paper, we introduce a simple principle of consistency that argues that the relative similarities between pixels as imputed by the averaging matrix should be preserved in the filtered output. The resultant consistency filter has the theoretically desirable properties of being symmetric and stable, and is a generalized doubly stochastic matrix. In addition, we can also interpret our consistency filter as a specific form of Laplacian regularization. Thus, our approach unifies two strands of image denoising methods, i.e., symmetric smoothing filters and spectral graph theory. Our consistency filter provides high-quality image denoising and significantly outperforms the doubly stochastic version. We present a thorough analysis of the properties of our proposed consistency filter and compare its performance with that of other significant methods for image denoising in the literature.

  17. Mechanosensitive ion channels in interstitial cells of Cajal and smooth muscle of the gastrointestinal tract.

    PubMed

    Kraichely, R E; Farrugia, G

    2007-04-01

    Normal gastrointestinal (GI) motility is required to mix digestive enzymes and food and to move content along the GI tract. Underlying the complex motor patterns of the gut are electrical events that reflect ion flux across cell membranes. Smooth muscle electrical activity is directly influenced by GI interstitial cells of Cajal, whose rhythmic oscillations in membrane potential in part determine the excitability of GI smooth muscle and its response to neuronal input. Coordinated activity of the ion channels responsible for the conductances that underlie ion flux in both smooth muscle and interstitial cells is a requisite for normal motility. These conductances are regulated by many factors, including mechanical stress. Recent studies have revealed mechanosensitivity at the level of the ion channels, and the mechanosensor within the channel has been identified in many cases. This has led to better comprehension of the role of mechanosensitive conductances in normal physiology and will undoubtedly lead to understanding of the consequences of disturbances in these conductances.

  18. Upregulation of decorin by FXR in vascular smooth muscle cells

    SciTech Connect

    He Fengtian; Zhang Qiuhong; Kuruba, Ramalinga; Gao Xiang; Li Jiang; Li Yong; Gong Wei; Jiang, Yu; Xie Wen; Li Song

    2008-08-08

    Decorin is a member of the family of small leucine-rich proteoglycans that are present in blood vessels and synthesized by vascular smooth muscle cells (VSMCs). Decorin plays complex roles in both normal vascular physiology and the pathogenesis of various types of vascular disorders. However, the mechanisms of regulation of decorin expression in vasculature are not clearly understood. Particularly little information is available about a role of nuclear receptors in the regulation of decorin expression. In the present study, we report that activation of vascular FXR by a specific ligand resulted in upregulation of decorin at the levels of both mRNA and protein. FXR appears to induce decorin expression at a transcriptional level because (1) upregulation of decorin mRNA expression was abolished by the treatment of a transcription inhibitor, actinomycin D; and (2) decorin promoter activity was significantly increased by activation of FXR. Functional analysis of human decorin promoter identified an imperfect inverted repeat DNA motif, IR8 (-2313TGGTCAtagtgtcaTGACCT-2294), as a likely FXR-responsive element that is involved in decorin regulation.

  19. 7 CFR 51.772 - Fairly smooth texture.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Definitions § 51.772 Fairly smooth texture. Fairly smooth texture means that the skin is fairly thin and not coarse for the variety and size of the fruit. “Fairly thin” means that the skin thickness does...

  20. 7 CFR 51.772 - Fairly smooth texture.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Definitions § 51.772 Fairly smooth texture. Fairly smooth texture means that the skin is fairly thin and not coarse for the variety and size of the fruit. “Fairly thin” means that the skin thickness does...

  1. A Kalman Filter with Smoothing for Hurricane Tracking and Prediction

    DTIC Science & Technology

    1989-12-01

    algorithms were categorized into three groups by Meditch [Ref. 51; Fixed Point Smoothing smooths the estimate iox at a fixed point k as K increases... Smoothing , Storm Trackig. I bstract (continue on reiersc if necr!:ry and ldetif by block number) T-he Performance of a Kalmnan filter used to track a...hurricane was substantially improved by implementing a fixed interval smoothing algofitin. This tracking routine was designed and imiplemencrted in a

  2. Cytoskeletal remodeling in differentiated vascular smooth muscle is actin isoform dependent and stimulus dependent.

    PubMed

    Kim, Hak Rim; Gallant, Cynthia; Leavis, Paul C; Gunst, Susan J; Morgan, Kathleen G

    2008-09-01

    Dynamic remodeling of the actin cytoskeleton plays an essential role in the migration and proliferation of vascular smooth muscle cells. It has been suggested that actin remodeling may also play an important functional role in nonmigrating, nonproliferating differentiated vascular smooth muscle (dVSM). In the present study, we show that contractile agonists increase the net polymerization of actin in dVSM, as measured by the differential ultracentrifugation of vascular smooth muscle tissue and the costaining of single freshly dissociated cells with fluorescent probes specific for globular and filamentous actin. Furthermore, induced alterations of the actin polymerization state, as well as actin decoy peptides, inhibit contractility in a stimulus-dependent manner. Latrunculin pretreatment or actin decoy peptides significantly inhibit contractility induced by a phorbol ester or an alpha-agonist, but these procedures have no effect on contractions induced by KCl. Aorta dVSM expresses alpha-smooth muscle actin, beta-actin, nonmuscle gamma-actin, and smooth muscle gamma-actin. The incorporation of isoform-specific cell-permeant synthetic actin decoy peptides, as well as isoform-specific probing of cell fractions and two-dimensional gels, demonstrates that actin remodeling during alpha-agonist contractions involves the remodeling of primarily gamma-actin and, to a lesser extent, beta-actin. Taken together, these results show that net isoform- and agonist-dependent increases in actin polymerization regulate vascular contractility.

  3. Neurophysiology and Neuroanatomy of Smooth Pursuit in Humans

    ERIC Educational Resources Information Center

    Lencer, Rebekka; Trillenberg, Peter

    2008-01-01

    Smooth pursuit eye movements enable us to focus our eyes on moving objects by utilizing well-established mechanisms of visual motion processing, sensorimotor transformation and cognition. Novel smooth pursuit tasks and quantitative measurement techniques can help unravel the different smooth pursuit components and complex neural systems involved…

  4. Alternative Smoothing and Scaling Strategies for Weighted Composite Scores

    ERIC Educational Resources Information Center

    Moses, Tim

    2014-01-01

    In this study, smoothing and scaling approaches are compared for estimating subscore-to-composite scaling results involving composites computed as rounded and weighted combinations of subscores. The considered smoothing and scaling approaches included those based on raw data, on smoothing the bivariate distribution of the subscores, on smoothing…

  5. The Optimal Degree of Smoothing in Equipercentile Equating with Postsmoothing.

    ERIC Educational Resources Information Center

    Zeng, Lingjia

    1995-01-01

    The effects of different degrees of smoothing on results of equipercentile equating in random groups design using a postsmoothing method based on cubic splines were investigated, and a computer-based procedure was introduced for selecting a desirable degree of smoothing. Results suggest that no particular degree of smoothing was always optimal.…

  6. Infant Attention and the Development of Smooth Pursuit Tracking.

    ERIC Educational Resources Information Center

    Richards, John E.; Holley, Felecia B.

    1999-01-01

    Studied effect of attention on smooth pursuit and saccadic tracking in infants at 8, 14, 20, and 26 weeks old. Found an increase across age in overall tracking, gain of smooth-pursuit eye movements, and increased amplitude of compensatory saccades at faster tracking speeds. Findings show that development of smooth pursuit, targeted saccadic eye…

  7. Visual Short-Term Memory During Smooth Pursuit Eye Movements

    ERIC Educational Resources Information Center

    Kerzel, Dirk; Ziegler, Nathalie E.

    2005-01-01

    Visual short-term memory (VSTM) was probed while observers performed smooth pursuit eye movements. Smooth pursuit keeps a moving object stabilized in the fovea. VSTM capacity for position was reduced during smooth pursuit compared with a condition with eye fixation. There was no difference between a condition in which the items were approximately…

  8. Smooth muscle-selective CPI-17 expression increases vascular smooth muscle contraction and blood pressure

    PubMed Central

    Su, Wen; Xie, Zhongwen; Liu, Shu; Calderon, Lindsay E.; Guo, Zhenheng

    2013-01-01

    Recent data revealed that protein kinase C-potentiated myosin phosphatase inhibitor of 17 kDa (CPI-17), a myosin phosphatase inhibitory protein preferentially expressed in smooth muscle, is upregulated/activated in several diseases but whether this CPI-17 increase plays a causal role in pathologically enhanced vascular smooth muscle contractility and blood pressure remains unclear. To address this possibility, we generated a smooth muscle-specific CPI-17 transgenic mouse model (CPI-17-Tg) and demonstrated that the CPI-17 transgene was selectively expressed in smooth muscle-enriched tissues, including mesenteric arteries. The isometric contractions in the isolated second-order branch of mesenteric artery helical strips from CPI-17-Tg mice were significantly enhanced compared with controls in response to phenylephrine, U-46619, serotonin, ANG II, high potassium, and calcium. The perfusion pressure increases in isolated perfused mesenteric vascular beds in response to norepinephrine were also enhanced in CPI-17-Tg mice. The hypercontractility was associated with increased phosphorylation of CPI-17 and 20-kDa myosin light chain under basal and stimulated conditions. Surprisingly, the protein levels of rho kinase 2 and protein kinase Cα/δ were significantly increased in CPI-17-Tg mouse mesenteric arteries. Radiotelemetry measurements demonstrated that blood pressure was significantly increased in CPI-17-Tg mice. However, no vascular remodeling was detected by morphometric analysis. Taken together, our results demonstrate that increased CPI-17 expression in smooth muscle promotes vascular smooth muscle contractility and increases blood pressure, implicating a pathological significant role of CPI-17 upregulation. PMID:23604714

  9. Irregular Wave Runup on Smooth Slopes.

    DTIC Science & Technology

    1981-12-01

    CERC- CETA -81-17 N. IE D CETA 81-17 Z Irregular Wave Runup on Smooth Slopes by ot John P. Ahrens COASTAL ENGINEERING TECHNICAL AID NO. 81-17 DECEMBER...GOVT ACCESSION NO, 3. RECIPIENT’S CATALOG NUMBER CETA 811 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Coastal Engineering IRREGULAR...Coastal Engineering Research Center, 1977); CETA 77-2 "Prediction of Irregular Wave Runup" by John P. Ahrens; and CETA 78-2 "Revised Wave Runup

  10. Old Basin Filled by Smooth Plains

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Old basin, 190 km in diameter, filled by smooth plains at 43 degrees S, 55 degrees W. The basin's hummocky rim is partly degraded and cratered by later events. Mariner 10 frame 166607.

    The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

    Image Credit: NASA/JPL/Northwestern University

  11. Workshop on advances in smooth particle hydrodynamics

    SciTech Connect

    Wingate, C.A.; Miller, W.A.

    1993-12-31

    This proceedings contains viewgraphs presented at the 1993 workshop held at Los Alamos National Laboratory. Discussed topics include: negative stress, reactive flow calculations, interface problems, boundaries and interfaces, energy conservation in viscous flows, linked penetration calculations, stability and consistency of the SPH method, instabilities, wall heating and conservative smoothing, tensors, tidal disruption of stars, breaking the 10,000,000 particle limit, modelling relativistic collapse, SPH without H, relativistic KSPH avoidance of velocity based kernels, tidal compression and disruption of stars near a supermassive rotation black hole, and finally relativistic SPH viscosity and energy.

  12. Smoothed Analysis for the Conjugate Gradient Algorithm

    NASA Astrophysics Data System (ADS)

    Menon, Govind; Trogdon, Thomas

    2016-11-01

    The purpose of this paper is to establish bounds on the rate of convergence of the conjugate gradient algorithm when the underlying matrix is a random positive definite perturbation of a deterministic positive definite matrix. We estimate all finite moments of a natural halting time when the random perturbation is drawn from the Laguerre unitary ensemble in a critical scaling regime explored in Deift et al. (2016). These estimates are used to analyze the expected iteration count in the framework of smoothed analysis, introduced by Spielman and Teng (2001). The rigorous results are compared with numerical calculations in several cases of interest.

  13. Method for producing smooth inner surfaces

    DOEpatents

    Cooper, Charles A.

    2016-05-17

    The invention provides a method for preparing superconducting cavities, the method comprising causing polishing media to tumble by centrifugal barrel polishing within the cavities for a time sufficient to attain a surface smoothness of less than 15 nm root mean square roughness over approximately a 1 mm.sup.2 scan area. The method also provides for a method for preparing superconducting cavities, the method comprising causing polishing media bound to a carrier to tumble within the cavities. The method also provides for a method for preparing superconducting cavities, the method comprising causing polishing media in a slurry to tumble within the cavities.

  14. Compressive Sensing via Nonlocal Smoothed Rank Function

    PubMed Central

    Fan, Ya-Ru; Liu, Jun; Zhao, Xi-Le

    2016-01-01

    Compressive sensing (CS) theory asserts that we can reconstruct signals and images with only a small number of samples or measurements. Recent works exploiting the nonlocal similarity have led to better results in various CS studies. To better exploit the nonlocal similarity, in this paper, we propose a non-convex smoothed rank function based model for CS image reconstruction. We also propose an efficient alternating minimization method to solve the proposed model, which reduces a difficult and coupled problem to two tractable subproblems. Experimental results have shown that the proposed method performs better than several existing state-of-the-art CS methods for image reconstruction. PMID:27583683

  15. Compressive Sensing via Nonlocal Smoothed Rank Function.

    PubMed

    Fan, Ya-Ru; Huang, Ting-Zhu; Liu, Jun; Zhao, Xi-Le

    2016-01-01

    Compressive sensing (CS) theory asserts that we can reconstruct signals and images with only a small number of samples or measurements. Recent works exploiting the nonlocal similarity have led to better results in various CS studies. To better exploit the nonlocal similarity, in this paper, we propose a non-convex smoothed rank function based model for CS image reconstruction. We also propose an efficient alternating minimization method to solve the proposed model, which reduces a difficult and coupled problem to two tractable subproblems. Experimental results have shown that the proposed method performs better than several existing state-of-the-art CS methods for image reconstruction.

  16. Impact modeling with Smooth Particle Hydrodynamics

    SciTech Connect

    Stellingwerf, R.F.; Wingate, C.A.

    1993-07-01

    Smooth Particle Hydrodynamics (SPH) can be used to model hypervelocity impact phenomena via the addition of a strength of materials treatment. SPH is the only technique that can model such problems efficiently due to the combination of 3-dimensional geometry, large translations of material, large deformations, and large void fractions for most problems of interest. This makes SPH an ideal candidate for modeling of asteroid impact, spacecraft shield modeling, and planetary accretion. In this paper we describe the derivation of the strength equations in SPH, show several basic code tests, and present several impact test cases with experimental comparisons.

  17. Role played by Prx1-dependent extracellular matrix properties in vascular smooth muscle development in embryonic lungs

    PubMed Central

    Ames, Juliana; Chokshi, Mithil; Aiad, Norman; Sanyal, Sonali; Kawabata, Kimihito C.; Levental, Ilya; Sundararaghavan, Harini G.; Burdick, Jason A.; Janmey, Paul; Miyazono, Kohei; Wells, Rebecca G.; Jones, Peter L.

    2015-01-01

    Abstract Although there are many studies focusing on the molecular pathways underlying lung vascular morphogenesis, the extracellular matrix (ECM)–dependent regulation of mesenchymal cell differentiation in vascular smooth muscle development needs better understanding. In this study, we demonstrate that the paired related homeobox gene transcription factor Prx1 maintains the elastic ECM properties, which are essential for vascular smooth muscle precursor cell differentiation. We have found that Prx1null mouse lungs exhibit defective vascular smooth muscle development, downregulated elastic ECM expression, and compromised transforming growth factor (TGF)–β localization and signaling. Further characterization of ECM properties using decellularized lung ECM scaffolds derived from Prx1 mice demonstrated that Prx1 is required to maintain lung ECM stiffness. The results of cell culture using stiffness-controlled 2-D and 3-D synthetic substrates confirmed that Prx1-dependent ECM stiffness is essential for promotion of smooth muscle precursor differentiation for effective TGF-β stimulation. Supporting these results, both decellularized Prx1null lung ECM and Prx1WT (wild type) ECM scaffolds with blocked TGF-β failed to support mesenchymal cell to 3-D smooth muscle cell differentiation. These results suggest a novel ECM-dependent regulatory pathway of lung vascular development wherein Prx1 regulates lung vascular smooth muscle precursor development by coordinating the ECM biophysical and biochemical properties. PMID:26064466

  18. Airway smooth muscle growth in asthma: proliferation, hypertrophy, and migration.

    PubMed

    Bentley, J Kelley; Hershenson, Marc B

    2008-01-01

    Increased airway smooth muscle mass is present in fatal and non-fatal asthma. However, little information is available regarding the cellular mechanism (i.e., hyperplasia vs. hypertrophy). Even less information exists regarding the functional consequences of airway smooth muscle remodeling. It would appear that increased airway smooth muscle mass would tend to increase airway narrowing and airflow obstruction. However, the precise effects of increased airway smooth muscle mass on airway narrowing are not known. This review will consider the evidence for airway smooth muscle cell proliferation and hypertrophy in asthma, potential functional effects, and biochemical mechanisms.

  19. A Novel System for Studying Mechanical Strain Waveform-Dependent Responses in Vascular Smooth Muscle Cells

    PubMed Central

    Lee, Jason; Wong, Mitchell; Smith, Quentin; Baker, Aaron B.

    2013-01-01

    While many studies have examined the effects mechanical forces on vSMCs, there is a limited understanding of how the different arterial strain waveforms that occur in disease and different vascular beds alter vSMC mechanotransduction and phenotype. Here, we present a novel system for applying complex, time-varying strain waveforms to cultured cells and use this system to understand how these waveforms can alter vSMC phenotype and signaling. We have developed a highly adaptable cell culture system that allows the application of mechanical strain to cells in culture and can reproduce the complex dynamic mechanical environment experienced by arterial cells in the body. Using this system, we examined whether the type of applied strain waveform altered phenotypic modulation of vSMCs by mechanical forces. Cells exposed to the brachial waveform had increased phosphorylation of AKT, EGR-1, c-Fos expression and cytoskeletal remodeling in comparison to cells treated with the aortic waveform. In addition, vSMCs exposed to physiological waveforms had adopted a more differentiated phenotype in comparison to those treated with static or sinusoidal cyclic strain, with increased expression of vSMC markers desmin, calponin and SM-22 as well as increased expression of regulatory miRNAs including miR-143, -145 and -221. Taken together, our studies demonstrate the development of a novel system for applying complex, timevarying mechanical forces to cells in culture. In addition, we have shown that physiological strain waveforms have powerful effects on vSMC phenotype. PMID:24096612

  20. A generalized smoothness criterion for acoustic-to-articulatory inversion

    PubMed Central

    Ghosh, Prasanta Kumar; Narayanan, Shrikanth

    2010-01-01

    The many-to-one mapping from representations in the speech articulatory space to acoustic space renders the associated acoustic-to-articulatory inverse mapping non-unique. Among various techniques, imposing smoothness constraints on the articulator trajectories is one of the common approaches to handle the non-uniqueness in the acoustic-to-articulatory inversion problem. This is because, articulators typically move smoothly during speech production. A standard smoothness constraint is to minimize the energy of the difference of the articulatory position sequence so that the articulator trajectory is smooth and low-pass in nature. Such a fixed definition of smoothness is not always realistic or adequate for all articulators because different articulators have different degrees of smoothness. In this paper, an optimization formulation is proposed for the inversion problem, which includes a generalized smoothness criterion. Under such generalized smoothness settings, the smoothness parameter can be chosen depending on the specific articulator in a data-driven fashion. In addition, this formulation allows estimation of articulatory positions recursively over time without any loss in performance. Experiments with the MOCHA TIMIT database show that the estimated articulator trajectories obtained using such a generalized smoothness criterion have lower RMS error and higher correlation with the actual measured trajectories compared to those obtained using a fixed smoothness constraint. PMID:20968386

  1. Smooth Tubercle Bacilli: Neglected Opportunistic Tropical Pathogens

    PubMed Central

    Aboubaker Osman, Djaltou; Bouzid, Feriel; Canaan, Stéphane; Drancourt, Michel

    2016-01-01

    Smooth tubercle bacilli (STB) including “Mycobacterium canettii” are members of the Mycobacterium tuberculosis complex (MTBC), which cause non-contagious tuberculosis in human. This group comprises <100 isolates characterized by smooth colonies and cordless organisms. Most STB isolates have been obtained from patients exposed to the Republic of Djibouti but seven isolates, including the three seminal ones obtained by Georges Canetti between 1968 and 1970, were recovered from patients in France, Madagascar, Sub-Sahara East Africa, and French Polynesia. STB form a genetically heterogeneous group of MTBC organisms with large 4.48 ± 0.05 Mb genomes, which may link Mycobacterium kansasii to MTBC organisms. Lack of inter-human transmission suggested a yet unknown environmental reservoir. Clinical data indicate a respiratory tract route of contamination and the digestive tract as an alternative route of contamination. Further epidemiological and clinical studies are warranted to elucidate areas of uncertainty regarding these unusual mycobacteria and the tuberculosis they cause. PMID:26793699

  2. Smooth blasting with the electronic delay detonator

    SciTech Connect

    Yamamoto, Masaaki; Ichijo, Toshiyuki; Tanaka, Yoshiharu

    1995-12-31

    The authors utilized electronic detonators (EDs) to investigate the effect of high detonator delay accuracy on overbreak, remaining rock damage, and surface smoothness, in comparison with that of long-period delay detonators (0.25 sec interval) PDs. The experiments were conducted in a deep mine, in a test site region composed of very hard granodiorite with a seismic wave velocity of about 6.0 km/sec and a uniaxial compressive strength, uniaxial tensile strength, and Young`s modulus of 300 MPa, 12 MPa, and 73 GPa, respectively. The blasting design was for a test tunnel excavation of 8 m{sup 2} in cross section, with an advance per round of 2.5 m. Five rounds were performed, each with a large-hole cut and perimeter holes in a 0.4-m spacing charged with 20-mm-diameter water gel explosive to obtain low charge concentration. EDs were used in the holes on the perimeter of the right half, and PDs were used in all other holes. Following each shot, the cross section was measured by laser to determine amount of overbreak and surface smoothness. In situ seismic prospecting was used to estimate the depth of damage in the remaining rock, and the damage was further investigated by boring into both side walls.

  3. Sympathetic innervation promotes vascular smooth muscle differentiation.

    PubMed

    Damon, Deborah H

    2005-06-01

    The sympathetic nervous system (SNS) is an important modulator of vascular smooth muscle (VSM) growth and function. Several lines of evidence suggest that the SNS also promotes VSM differentiation. The present study tests this hypothesis. Expression of smooth muscle myosin (SM2) and alpha-actin were assessed by Western analysis as indexes of VSM differentiation. SM2 expression (normalized to alpha-actin) in adult innervated rat femoral and tail arteries was 479 +/- 115% of that in noninnervated carotid arteries. Expression of alpha-actin (normalized to GAPDH or total protein) in 30-day-innervated rat femoral arteries was greater than in corresponding noninnervated femoral arteries from guanethidine-sympathectomized rats. SM2 expression (normalized to alpha-actin) in neonatal femoral arteries grown in vitro for 7 days in the presence of sympathetic ganglia was greater than SM2 expression in corresponding arteries grown in the absence of sympathetic ganglia. In VSM-endothelial cell cultures grown in the presence of dissociated sympathetic neurons, alpha-actin (normalized to GAPDH) was 300 +/- 66% of that in corresponding cultures grown in the absence of neurons. This effect was inhibited by an antibody that neutralized the activity of transforming growth factor-beta2. All of these data indicate that sympathetic innervation increased VSM contractile protein expression and thereby suggest that the SNS promotes and/or maintains VSM differentiation.

  4. IP-10/CXCR3 Axis Promotes the Proliferation of Vascular Smooth Muscle Cells through ERK1/2/CREB Signaling Pathway.

    PubMed

    Wang, Hui-Jin; Zhou, Yu; Liu, Rui-Ming; Qin, Yuan-Sen; Cen, Ying-Huan; Hu, Ling-Yu; Wang, Shen-Ming; Hu, Zuo-Jun

    2017-03-01

    Excessive proliferation of vascular smooth muscle cells is one of the main pathological processes leading to atherosclerosis and intimal hyperplasia after vascular interventional therapy. Our previous study has shown that interferon-γ inducible protein-10 contributes to the proliferation of vascular smooth muscle cell. However, the underlying mechanisms remain unclear. Extracellular signal-regulated kinase 1/2, serine/threonine kinase Akt, and cAMP response element binding protein are signaling pathways, which are considered to play important roles in the processes of vascular smooth muscle cell proliferation. Moreover, chemokine receptor 3 and Toll-like receptor 4 are potential receptors of inducible protein-10 in this process. In the present study, IP-10 was found to directly induce vascular smooth muscle cell proliferation, and exposure to inducible protein-10 activated extracellular signal-regulated kinase 1/2, serine/threonine kinase, and cAMP response element binding protein signaling. Inhibitor of extracellular signal-regulated kinase 1/2, rather than inhibitor of serine/threonine kinase, inhibited the phosphorylation of cAMP response element binding protein and reduced inducible protein-10-stimulated vascular smooth muscle cell proliferation. Knockdown of cAMP response element binding protein by siRNA inhibited inducible protein-10-induced vascular smooth muscle cell proliferation. Moreover, anti-CXCR3 IgG, instead of anti-Toll-like receptor 4 IgG, reduced inducible protein-10-induced vascular smooth muscle cell proliferation and inducible protein-10-stimulated extracellular signal-regulated kinase 1/2 and cAMP response element binding protein activation. Together, these results indicate that inducible protein-10 promotes vascular smooth muscle cell proliferation via chemokine receptor 3 and activation of extracellular signal-regulated kinase 1/2 inducible protein-10-induced vascular smooth muscle cell proliferation. These data provide important targets

  5. Rho-kinase mediated cytoskeletal stiffness in skinned smooth muscle

    PubMed Central

    Lan, Bo; Wang, Lu; Zhang, Jenny; Pascoe, Chris D.; Norris, Brandon A.; Liu, Jeffrey C.-Y.; Solomon, Dennis; Paré, Peter D.; Deng, Linhong

    2013-01-01

    The structurally dynamic cytoskeleton is important in many cell functions. Large gaps still exist in our knowledge regarding what regulates cytoskeletal dynamics and what underlies the structural plasticity. Because Rho-kinase is an upstream regulator of signaling events leading to phosphorylation of many cytoskeletal proteins in many cell types, we have chosen this kinase as the focus of the present study. In detergent skinned tracheal smooth muscle preparations, we quantified the proteins eluted from the muscle cells over time and monitored the muscle's ability to respond to acetylcholine (ACh) stimulation to produce force and stiffness. In a partially skinned preparation not able to generate active force but could still stiffen upon ACh stimulation, we found that the ACh-induced stiffness was independent of calcium and myosin light chain phosphorylation. This indicates that the myosin light chain-dependent actively cycling crossbridges are not likely the source of the stiffness. The results also indicate that Rho-kinase is central to the ACh-induced stiffness, because inhibition of the kinase by H1152 (1 μM) abolished the stiffening. Furthermore, the rate of relaxation of calcium-induced stiffness in the skinned preparation was faster than that of ACh-induced stiffness, with or without calcium, suggesting that different signaling pathways lead to different means of maintenance of stiffness in the skinned preparation. PMID:24072407

  6. Traction in smooth muscle cells varies with cell spreading

    NASA Technical Reports Server (NTRS)

    Tolic-Norrelykke, Iva Marija; Wang, Ning

    2005-01-01

    Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.

  7. SREBP inhibits VEGF expression in human smooth muscle cells

    SciTech Connect

    Motoyama, Koka; Fukumoto, Shinya . E-mail: sfukumoto@med.osaka-cu.ac.jp; Koyama, Hidenori; Emoto, Masanori; Shimano, Hitoshi; Maemura, Koji; Nishizawa, Yoshiki

    2006-03-31

    Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate expression of genes encoding enzymes for lipid biosynthesis. SREBPs are activated by HMG-CoA reductase inhibitors (statins). Statins have been also reported to suppress vascular endothelial growth factor (VEGF) expression in vascular smooth muscle cells (VSMCs). Therefore, we hypothesized that SREBPs are involved in statin-mediated regulation of VEGF production in VSMCs. SREBP1 was robustly expressed, and was activated by atorvastatin in VSMCs, as demonstrated by increased levels of the mature nuclear form of SREBP1, and increased promoter activities of a reporter containing sterol regulatory elements by atorvastatin. Moreover, overexpression of SREBP1a dose-dependently suppressed VEGF promoter activity. Site-specific mutation or deletion of the proximal Sp1 sites reduced the inhibitory effects of SREBP1a on VEGF promoter activity. These data demonstrated that SREBP1, activated by atorvastatin, suppressed VEGF expression through the indirect interaction with the proximal tandem Sp1 sites in VSMCs.

  8. Vascular smooth muscle cell response on thin films of collagen.

    PubMed

    Elliott, John T; Woodward, John T; Langenbach, Kurt J; Tona, Alex; Jones, Peter L; Plant, Anne L

    2005-10-01

    Vascular smooth muscle cells (vSMC) cultured on gels of fibrillar type I collagen or denatured collagen (gelatin) comprise a model system that has been widely used for studying the role of the extracellular matrix in vascular diseases such as hypertension, restenosis and athrosclerosis. Despite the wide use of this model system, there are several disadvantages to using collagen gels for cellular studies. These include poor optical characteristics for microscopy, difficulty in verifying that the properties of the preparations are identical from experiment to experiment, heterogeneity within the gels, and difficulty in handling the gels because they are fragile. Previously, we developed an alternative collagen matrix by forming thin films of native fibrillar collagen or denatured collagen on self-assembled monolayers of alkanethiols [Elliott, J.T., Tona, A., Woodward, J., Jones,P., Plant, A., 2003a. Thin films of collagen affect smooth muscle cell morphology. Langmuir 19, 1506-1514.]. These substrates are robust and can be characterized by surface analytical techniques that allow both verification of the reproducibility of the preparation and high-resolution analysis of collagen structure. In addition, they have excellent optical properties that allow more details of the cell-matrix interactions to be observed by microscopy. In this study, we performed a side-by-side structural and functional comparison of collagen gels with thin films of collagen. Our results indicate that vSMC on thin films of collagen are nearly identical to vSMC on thick gels as determined by morphology, proliferation rate, integrin ligation, tenascin-C expression and intracellular signaling events. These results suggest that the features of collagen gels that direct the observed vSMC responses are adequately reconstituted in the thin films of collagen. These thin films will be useful for elucidating the features of the collagen matrix that regulate vSMC response and may be applicable to high

  9. [Physiological and pathophysiological meanings of gastrointestinal smooth muscle motor unit SIP syncytium].

    PubMed

    Song, Ni-Na; Xu, Wen-Xie

    2016-10-25

    Gastrointestinal smooth muscle layer contains two kinds of interstitial cells with special differentiation, i.e., interstitial cells of Cajal (ICC) and platelet-derived growth factor receptor α-positive (PDGFRα(+)) cells. The ICC and PDGFRα(+) cells contact with smooth muscle cells (SMCs) by gap junctions and regulate contractive function of the SMCs. Therefore, these three kinds of cells constitute a functional syncytium, i.e., the SMC, ICC and PDGFRα(+) cells syncytium (SIP syncytium). Various neurotransmitters, humoral factors, endogenous bioactive molecules, as well as drugs regulate gastrointestinal motility through the SIP syncytium. In this review, we introduce the concept of SIP syncytium and summarize functions of the syncytium, as well as its physiological and pathological significances.

  10. Integration of proteomic and transcriptomic profiles identifies a novel PDGF-MYC network in human smooth muscle cells

    PubMed Central

    2014-01-01

    Background Platelet-derived growth factor-BB (PDGF-BB) has been implicated in the proliferation, migration and synthetic activities of smooth muscle cells that characterize physiologic and pathologic tissue remodeling in hollow organs. However, neither the molecular basis of PDGFR-regulated signaling webs, nor the extent to which specific components within these networks could be exploited for therapeutic benefit has been fully elucidated. Results Expression profiling and quantitative proteomics analysis of PDGF-treated primary human bladder smooth muscle cells identified 1,695 genes and 241 proteins as differentially expressed versus non-treated cells. Analysis of gene expression data revealed MYC, JUN, EGR1, MYB, RUNX1, as the transcription factors most significantly networked with up-regulated genes. Forty targets were significantly altered at both the mRNA and protein levels. Proliferation, migration and angiogenesis were the biological processes most significantly associated with this signature, and MYC was the most highly networked master regulator. Alterations in master regulators and gene targets were validated in PDGF-stimulated smooth muscle cells in vitro and in a model of bladder injury in vivo. Pharmacologic inhibition of MYC and JUN confirmed their role in SMC proliferation and migration. Network analysis identified the diaphanous-related formin 3 as a novel PDGF target regulated by MYC and JUN, which was necessary for PDGF-stimulated lamellipodium formation. Conclusions These findings provide the first systems-level analysis of the PDGF-regulated transcriptome and proteome in normal smooth muscle cells. The analyses revealed an extensive cohort of PDGF-dependent biological processes and connected key transcriptional effectors to their regulation, significantly expanding current knowledge of PDGF-stimulated signaling cascades. These observations also implicate MYC as a novel target for pharmacological intervention in fibroproliferative expansion of

  11. Segregation of striated and smooth muscle lineages by a Notch-dependent regulatory network

    PubMed Central

    2014-01-01

    Background Lineage segregation from multipotent epithelia is a central theme in development and in adult stem cell plasticity. Previously, we demonstrated that striated and smooth muscle cells share a common progenitor within their epithelium of origin, the lateral domain of the somite-derived dermomyotome. However, what controls the segregation of these muscle subtypes remains unknown. We use this in vivo bifurcation of fates as an experimental model to uncover the underlying mechanisms of lineage diversification from bipotent progenitors. Results Using the strength of spatio-temporally controlled gene missexpression in avian embryos, we report that Notch harbors distinct pro-smooth muscle activities depending on the duration of the signal; short periods prevent striated muscle development and extended periods, through Snail1, promote cell emigration from the dermomyotome towards a smooth muscle fate. Furthermore, we define a Muscle Regulatory Network, consisting of Id2, Id3, FoxC2 and Snail1, which acts in concert to promote smooth muscle by antagonizing the pro-myogenic activities of Myf5 and Pax7, which induce striated muscle fate. Notch and BMP closely regulate the network and reciprocally reinforce each other’s signal. In turn, components of the network strengthen Notch signaling, while Pax7 silences this signaling. These feedbacks augment the robustness and flexibility of the network regulating muscle subtype segregation. Conclusions Our results demarcate the details of the Muscle Regulatory Network, underlying the segregation of muscle sublineages from the lateral dermomyotome, and exhibit how factors within the network promote the smooth muscle at the expense of the striated muscle fate. This network acts as an exemplar demonstrating how lineage segregation occurs within epithelial primordia by integrating inputs from competing factors. PMID:25015411

  12. Smooth muscle BK channel activity influences blood pressure independent of vascular tone in mice

    PubMed Central

    Sachse, Gregor; Faulhaber, Jörg; Seniuk, Anika; Ehmke, Heimo; Pongs, Olaf

    2014-01-01

    The large conductance voltage- and Ca2+-activated K+ (BK) channel is an important determinant of vascular tone and contributes to blood pressure regulation. Both activities depend on the ancillary BKβ1 subunit. To determine the significance of smooth muscle BK channel activity for blood pressure regulation, we investigated the potential link between changes in arterial tone and altered blood pressure in BKβ1 knockout (BKβ1−/−) mice from three different genetically defined strains. While vascular tone was consistently increased in all BKβ1−/− mice independent of genetic background, BKβ1−/− strains exhibited increased (strain A), unaltered (strain B) or decreased (strain C) mean arterial blood pressures compared to their corresponding BKβ1+/+ controls. In agreement with previous data on aldosterone regulation by renal/adrenal BK channel function, BKβ1−/− strain A mice have increased plasma aldosterone and increased blood pressure. Consistently, blockade of mineralocorticoid receptors by spironolactone treatment reversibly restored the elevated blood pressure to the BKβ1+/+ strain A level. In contrast, loss of BKβ1 did not affect plasma aldosterone in strain C mice. Smooth muscle-restricted restoration of BKβ1 expression increased blood pressure in BKβ1−/− strain C mice, implying that impaired smooth muscle BK channel activity lowers blood pressure in these animals. We conclude that BK channel activity directly affects vascular tone but influences blood pressure independent of this effect via different pathways. PMID:24687584

  13. Magnesium used in bioabsorbable stents controls smooth muscle cell proliferation and stimulates endothelial cells in vitro.

    PubMed

    Sternberg, Katrin; Gratz, Matthias; Koeck, Kathleen; Mostertz, Joerg; Begunk, Robert; Loebler, Marian; Semmling, Beatrice; Seidlitz, Anne; Hildebrandt, Petra; Homuth, Georg; Grabow, Niels; Tuemmler, Conny; Weitschies, Werner; Schmitz, Klaus-Peter; Kroemer, Heyo K

    2012-01-01

    Magnesium-based bioabsorbable cardiovascular stents have been developed to overcome limitations of permanent metallic stents, such as late stent thrombosis. During stent degradation, endothelial and smooth muscle cells will be exposed to locally high magnesium concentrations with yet unknown physiological consequences. Here, we investigated the effects of elevated magnesium concentrations on human coronary artery endothelial and smooth muscle cell (HCAEC, HCASMC) growth and gene expression. In the course of 24 h after incubation with magnesium chloride solutions (1 or 10 mM) intracellular magnesium level in HCASMC raised from 0.55 ± 0.25 mM (1 mM) to 1.38 ± 0.95 mM (10 mM), while no increase was detected in HCAEC. Accordingly, a DNA microarray-based study identified 69 magnesium regulated transcripts in HCAEC, but 2172 magnesium regulated transcripts in HCASMC. Notably, a significant regulation of various growth factors and extracellular matrix components was observed. In contrast, viability and proliferation of HCAEC were increased at concentrations of up to 25 mM magnesium chloride, while in HCASMC viability and proliferation appeared to be unaffected. Taken together, our data indicate that magnesium halts smooth muscle cell proliferation and stimulates endothelial cell proliferation, which might translate into a beneficial effect in the setting of stent associated vascular injury.

  14. Hippo signaling is required for Notch-dependent smooth muscle differentiation of neural crest

    PubMed Central

    Manderfield, Lauren J.; Aghajanian, Haig; Engleka, Kurt A.; Lim, Lillian Y.; Liu, Feiyan; Jain, Rajan; Li, Li; Olson, Eric N.; Epstein, Jonathan A.

    2015-01-01

    Notch signaling has well-defined roles in the assembly of arterial walls and in the development of the endothelium and smooth muscle of the vasculature. Hippo signaling regulates cellular growth in many tissues, and contributes to regulation of organ size, in addition to other functions. Here, we show that the Notch and Hippo pathways converge to regulate smooth muscle differentiation of the neural crest, which is crucial for normal development of the aortic arch arteries and cranial vasculature during embryonic development. Neural crest-specific deletion of the Hippo effectors Yap and Taz produces neural crest precursors that migrate normally, but fail to produce vascular smooth muscle, and Notch target genes such as Jagged1 fail to activate normally. We show that Yap is normally recruited to a tissue-specific Jagged1 enhancer by directly interacting with the Notch intracellular domain (NICD). The Yap-NICD complex is recruited to chromatin by the DNA-binding protein Rbp-J in a Tead-independent fashion. Thus, Hippo signaling can modulate Notch signaling outputs, and components of the Hippo and Notch pathways physically interact. Convergence of Hippo and Notch pathways by the mechanisms described here might be relevant for the function of these signaling cascades in many tissues and in diseases such as cancer. PMID:26253400

  15. PV output smoothing with energy storage.

    SciTech Connect

    Ellis, Abraham; Schoenwald, David Alan

    2012-03-01

    This report describes an algorithm, implemented in Matlab/Simulink, designed to reduce the variability of photovoltaic (PV) power output by using a battery. The purpose of the battery is to add power to the PV output (or subtract) to smooth out the high frequency components of the PV power that that occur during periods with transient cloud shadows on the PV array. The control system is challenged with the task of reducing short-term PV output variability while avoiding overworking the battery both in terms of capacity and ramp capability. The algorithm proposed by Sandia is purposely very simple to facilitate implementation in a real-time controller. The control structure has two additional inputs to which the battery can respond. For example, the battery could respond to PV variability, load variability or area control error (ACE) or a combination of the three.

  16. Computational brittle fracture using smooth particle hydrodynamics

    SciTech Connect

    Mandell, D.A.; Wingate, C.A.; Schwalbe, L.A.

    1996-10-01

    We are developing statistically based, brittle-fracture models and are implementing them into hydrocodes that can be used for designing systems with components of ceramics, glass, and/or other brittle materials. Because of the advantages it has simulating fracture, we are working primarily with the smooth particle hydrodynamics code SPBM. We describe a new brittle fracture model that we have implemented into SPBM. To illustrate the code`s current capability, we have simulated a number of experiments. We discuss three of these simulations in this paper. The first experiment consists of a brittle steel sphere impacting a plate. The experimental sphere fragment patterns are compared to the calculations. The second experiment is a steel flyer plate in which the recovered steel target crack patterns are compared to the calculated crack patterns. We also briefly describe a simulation of a tungsten rod impacting a heavily confined alumina target, which has been recently reported on in detail.

  17. Cobalt contraction of vascular smooth muscle

    SciTech Connect

    Dominiczak, A.; Clyde, E.; Bohr, D. )

    1991-03-11

    Although it has been reported that cobalt causes contraction of vascular smooth muscle, the mechanism responsible for this contraction has not been defined. The authors studied these contractions in rat aortic rings. Concentration-response studies indicated that the threshold for contraction was 10{sup {minus}8}M, maximum contraction occurred at 3 {times} 10{sup 7}M and relaxation began at 10{sup {minus}6}M. No contraction occurred in a calcium-free physiological salt solution and the contraction was not inhibited by H-7, a protein kinase C inhibitor. The authors conclude the cobalt in low concentrations causes contraction by activating calcium channels and that in high concentrations it causes relaxation by inactivating these same channels.

  18. How a Nanodroplet Diffuses on Smooth Surfaces

    NASA Astrophysics Data System (ADS)

    Li, Chu; Huang, Jizu; Li, Zhigang

    2016-11-01

    In this study, we investigate how nanodroplets diffuse on smooth surfaces through molecular dynamics (MD) simulations and theoretical analyses. The simulations results show that the surface diffusion of nanodroplet is different from that of single molecules and solid nanoparticles. The dependence of nanodroplet diffusion coefficient on temperature is surface wettability dependent, which undergoes a transition from linear to nonlinear as the surface wettability is weakened due to the coupling of temperature and surface energy. We also develop a simple relation for the diffusion coefficient by using the contact angle and contact radius of the droplet. It works well for different surface wettabilities and sized nanodroplets, as confirmed by MD simulations. This work was supported by the Research Grants Council of the Hong Kong Special Administrative Region under Grant No. 615312.

  19. An analysis of smoothed particle hydrodynamics

    SciTech Connect

    Swegle, J.W.; Attaway, S.W.; Heinstein, M.W.; Mello, F.J.; Hicks, D.L.

    1994-03-01

    SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian technique which is appealing as a possible alternative to numerical techniques currently used to analyze high deformation impulsive loading events. In the present study, the SPH algorithm has been subjected to detailed testing and analysis to determine its applicability in the field of solid dynamics. An important result of the work is a rigorous von Neumann stability analysis which provides a simple criterion for the stability or instability of the method in terms of the stress state and the second derivative of the kernel function. Instability, which typically occurs only for solids in tension, results not from the numerical time integration algorithm, but because the SPH algorithm creates an effective stress with a negative modulus. The analysis provides insight into possible methods for removing the instability. Also, SPH has been coupled into the transient dynamics finite element code PRONTO, and a weighted residual derivation of the SPH equations has been obtained.

  20. Subjective scaling of smooth surface friction.

    PubMed

    Smith, A M; Scott, S H

    1996-05-01

    1. Six men and four women, 30-51 yr of age, were asked to use the tip of the washed and dried index finger to stroke six different featureless, flat surfaces mounted on a three-dimensional force platform. The six surfaces were rosin-coated glass, glass, satin-finished aluminum, poly-vinyl chloride (PVC) plastic, Teflon, and nyloprint (polyamide plastic). The subjects were requested to indicate where the sensation produced by each surface should be placed on an unidimensional scale represented by an 18cm line labeled at one end by the words "most slippery" and at the other end by the words "most sticky." The coefficients of friction for each surface and for each subject were subsequently assessed by asking each subject to stroke the surfaces as if they were assessing its slipperiness for 5 s. 2. The finger forces normal and tangential to the stroked surfaces were digitized at 250 Hz and stored on a laboratory computer. The ratio of the mean tangential force to the mean perpendicular force during stroking was used to calculate the mean coefficient of kinetic friction. The mean friction for all subjects ranged from 0.43 for the nyloprint surface to 2.79 for the rosin-coated glass. Correlation coefficients calculated between the subjective estimates of friction and the measured coefficients of friction for each subject individually resulted in a mean correlation of 0.85 (n = 10, P < 0.001). 3. These data indicate that subjects can accurately scale relative differences in the friction of macroscopically smooth, flat surfaces, by modulating the tangential force applied to the finger while keeping the normal force relatively constant. The fact that subjects maintained a relatively constant normal force and instead varied the tangential force across different surfaces suggests that receptors sensitive to these tangential forces are important in the perception of smooth surface friction.

  1. Binocular Depth Judgments on Smoothly Curved Surfaces

    PubMed Central

    Hornsey, Rebecca L.; Scarfe, Peter

    2016-01-01

    Binocular disparity is an important cue to depth, allowing us to make very fine discriminations of the relative depth of objects. In complex scenes, this sensitivity depends on the particular shape and layout of the objects viewed. For example, judgments of the relative depths of points on a smoothly curved surface are less accurate than those for points in empty space. It has been argued that this occurs because depth relationships are represented accurately only within a local spatial area. A consequence of this is that, when judging the relative depths of points separated by depth maxima and minima, information must be integrated across separate local representations. This integration, by adding more stages of processing, might be expected to reduce the accuracy of depth judgements. We tested this idea directly by measuring how accurately human participants could report the relative depths of two dots, presented with different binocular disparities. In the first, Two Dot condition the two dots were presented in front of a square grid. In the second, Three Dot condition, an additional dot was presented midway between the target dots, at a range of depths, both nearer and further than the target dots. In the final, Surface condition, the target dots were placed on a smooth surface defined by binocular disparity cues. In some trials, this contained a depth maximum or minimum between the target dots. In the Three Dot condition, performance was impaired when the central dot was presented with a large disparity, in line with predictions. In the Surface condition, performance was worst when the midpoint of the surface was at a similar distance to the targets, and relatively unaffected when there was a large depth maximum or minimum present. These results are not consistent with the idea that depth order is represented only within a local spatial area. PMID:27824895

  2. Smooth Pursuit of Flicker-Defined Motion

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.; Stevenson, Scott B.

    2014-01-01

    We examined the pursuit response to stimuli defined by space-variant flicker of a dense random dot carrier pattern. On each frame, every element of the pattern could change polarity, with a probability given by a two-dimensional Gaussian distribution. A normal distribution produces a circular region of twinkle, while inverting the distribution results in a spot of static texture in a twinkling surround. In this latter case, the carrier texture could be stationary, or could move with the twinkle modulator, thereby producing first-order motion in the region of the spot. While the twinkle-defined spot produces a strong sensation of motion, the complementary stimulus defined by the absence of twinkle does not, when viewed peripherally, it appears to move in steps even when the generating distribution moves smoothly. We examined pursuit responses to these stimuli using two techniques: 1) the eye movement correlogram, obtained by cross-correlating eye velocity with the velocity of a randomly-moving stimulus; and 2) delayed visual feedback, where transient stabilization of a target can produce spontaneous oscillations of the eye, with a period empirically observed to vary linearly with the applied delay. Both techniques provide an estimate of the internal processing time, which can be as short as 100 milliseconds for a first-order target. Assessed by the correlogram method, the response to flicker-defined motion is delayed by more than 100 milliseconds, and significantly weaker (especially in the vertical dimension). When initially presented in the delayed feedback condition, purely saccadic oscillation is observed. One subject eventually developed smooth oscillations (albeit with significant saccadic intrusions), showing a period-versus-delay slope similar to that observed for first-order targets. This result is somewhat surprising, given that we interpret the slope of the period-versus-delay-function as reflecting the balance between position- and velocity

  3. Local, smooth, and consistent Jacobi set simplification

    SciTech Connect

    Bhatia, Harsh; Wang, Bei; Norgard, Gregory; Pascucci, Valerio; Bremer, Peer -Timo

    2014-10-31

    The relation between two Morse functions defined on a smooth, compact, and orientable 2-manifold can be studied in terms of their Jacobi set. The Jacobi set contains points in the domain where the gradients of the two functions are aligned. Both the Jacobi set itself as well as the segmentation of the domain it induces, have shown to be useful in various applications. In practice, unfortunately, functions often contain noise and discretization artifacts, causing their Jacobi set to become unmanageably large and complex. Although there exist techniques to simplify Jacobi sets, they are unsuitable for most applications as they lack fine-grained control over the process, and heavily restrict the type of simplifications possible. In this paper, we introduce a new framework that generalizes critical point cancellations in scalar functions to Jacobi set in two dimensions. We present a new interpretation of Jacobi set simplification based on the perspective of domain segmentation. Generalizing the cancellation of critical points from scalar functions to Jacobi sets, we focus on simplifications that can be realized by smooth approximations of the corresponding functions, and show how these cancellations imply simultaneous simplification of contiguous subsets of the Jacobi set. Using these extended cancellations as atomic operations, we introduce an algorithm to successively cancel subsets of the Jacobi set with minimal modifications to some user-defined metric. We show that for simply connected domains, our algorithm reduces a given Jacobi set to its minimal configuration, that is, one with no birth–death points (a birth–death point is a specific type of singularity within the Jacobi set where the level sets of the two functions and the Jacobi set have a common normal direction).

  4. Local, smooth, and consistent Jacobi set simplification

    DOE PAGES

    Bhatia, Harsh; Wang, Bei; Norgard, Gregory; ...

    2014-10-31

    The relation between two Morse functions defined on a smooth, compact, and orientable 2-manifold can be studied in terms of their Jacobi set. The Jacobi set contains points in the domain where the gradients of the two functions are aligned. Both the Jacobi set itself as well as the segmentation of the domain it induces, have shown to be useful in various applications. In practice, unfortunately, functions often contain noise and discretization artifacts, causing their Jacobi set to become unmanageably large and complex. Although there exist techniques to simplify Jacobi sets, they are unsuitable for most applications as they lackmore » fine-grained control over the process, and heavily restrict the type of simplifications possible. In this paper, we introduce a new framework that generalizes critical point cancellations in scalar functions to Jacobi set in two dimensions. We present a new interpretation of Jacobi set simplification based on the perspective of domain segmentation. Generalizing the cancellation of critical points from scalar functions to Jacobi sets, we focus on simplifications that can be realized by smooth approximations of the corresponding functions, and show how these cancellations imply simultaneous simplification of contiguous subsets of the Jacobi set. Using these extended cancellations as atomic operations, we introduce an algorithm to successively cancel subsets of the Jacobi set with minimal modifications to some user-defined metric. We show that for simply connected domains, our algorithm reduces a given Jacobi set to its minimal configuration, that is, one with no birth–death points (a birth–death point is a specific type of singularity within the Jacobi set where the level sets of the two functions and the Jacobi set have a common normal direction).« less

  5. Diffusion tensor smoothing through weighted Karcher means

    PubMed Central

    Carmichael, Owen; Chen, Jun; Paul, Debashis; Peng, Jie

    2014-01-01

    Diffusion tensor magnetic resonance imaging (MRI) quantifies the spatial distribution of water Diffusion at each voxel on a regular grid of locations in a biological specimen by Diffusion tensors– 3 × 3 positive definite matrices. Removal of noise from DTI is an important problem due to the high scientific relevance of DTI and relatively low signal to noise ratio it provides. Leading approaches to this problem amount to estimation of weighted Karcher means of Diffusion tensors within spatial neighborhoods, under various metrics imposed on the space of tensors. However, it is unclear how the behavior of these estimators varies with the magnitude of DTI sensor noise (the noise resulting from the thermal e!ects of MRI scanning) as well as the geometric structure of the underlying Diffusion tensor neighborhoods. In this paper, we combine theoretical analysis, empirical analysis of simulated DTI data, and empirical analysis of real DTI scans to compare the noise removal performance of three kernel-based DTI smoothers that are based on Euclidean, log-Euclidean, and affine-invariant metrics. The results suggest, contrary to conventional wisdom, that imposing a simplistic Euclidean metric may in fact provide comparable or superior noise removal, especially in relatively unstructured regions and/or in the presence of moderate to high levels of sensor noise. On the contrary, log-Euclidean and affine-invariant metrics may lead to better noise removal in highly structured anatomical regions, especially when the sensor noise is of low magnitude. These findings emphasize the importance of considering the interplay of sensor noise magnitude and tensor field geometric structure when assessing Diffusion tensor smoothing options. They also point to the necessity for continued development of smoothing methods that perform well across a large range of scenarios. PMID:25419264

  6. Anisotropic Smoothing Improves DT-MRI-Based Muscle Fiber Tractography

    PubMed Central

    Buck, Amanda K. W.; Ding, Zhaohua; Elder, Christopher P.; Towse, Theodore F.; Damon, Bruce M.

    2015-01-01

    Purpose To assess the effect of anisotropic smoothing on fiber tracking measures, including pennation angle, fiber tract length, and fiber tract number in the medial gastrocnemius (MG) muscle in healthy subjects using diffusion-weighted magnetic resonance imaging (DW-MRI). Materials and Methods 3T DW-MRI data were used for muscle fiber tractography in the MG of healthy subjects. Anisotropic smoothing was applied at three levels (5%, 10%, 15%), and pennation angle, tract length, fiber tract number, fractional anisotropy, and principal eigenvector orientation were quantified for each smoothing level. Results Fiber tract length increased with pre-fiber tracking smoothing, and local heterogeneities in fiber direction were reduced. However, pennation angle was not affected by smoothing. Conclusion Modest anisotropic smoothing (10%) improved fiber-tracking results, while preserving structural features. PMID:26010830

  7. Image segmentation on adaptive edge-preserving smoothing

    NASA Astrophysics Data System (ADS)

    He, Kun; Wang, Dan; Zheng, Xiuqing

    2016-09-01

    Nowadays, typical active contour models are widely applied in image segmentation. However, they perform badly on real images with inhomogeneous subregions. In order to overcome the drawback, this paper proposes an edge-preserving smoothing image segmentation algorithm. At first, this paper analyzes the edge-preserving smoothing conditions for image segmentation and constructs an edge-preserving smoothing model inspired by total variation. The proposed model has the ability to smooth inhomogeneous subregions and preserve edges. Then, a kind of clustering algorithm, which reasonably trades off edge-preserving and subregion-smoothing according to the local information, is employed to learn the edge-preserving parameter adaptively. At last, according to the confidence level of segmentation subregions, this paper constructs a smoothing convergence condition to avoid oversmoothing. Experiments indicate that the proposed algorithm has superior performance in precision, recall, and F-measure compared with other segmentation algorithms, and it is insensitive to noise and inhomogeneous-regions.

  8. Modulation of the Cholinergic Mechanisms in the Bronchial Smooth Muscle.

    DTIC Science & Technology

    1984-06-01

    STANDARDS 16r A CD in UMODULATION OF THE CHOLINERGICMECHANISMS IN THE BRONCHIAL SMOOTH MUSCLE A THESIS SUBMITTED TO THE UNIVERSITY OF BERGEN FOR THE DOCTOR...MECHANISMS IN THE BRONCHIAL SMOOTH MUSCLE A THESIS SUBMITTED TO THE UNIVERSITY OF BERGEN FOR THE DOCTOR SCIENTIARUM DEGREE by Pi1 An E% LECTE3 NORE/PUBL-84...DECLASSIFICATION/DOWNGRADING SCHEDULE 118 FFITOX/465/001 4) TITLE MODULATION OF THE CHOLINERGIC MECHANISMS IN THE BRONCHIAL SMOOTH MUSCLE (A thesis submitted to

  9. Mitogenic effects of vasoactive neuropeptides on cultured smooth muscle cell lines

    SciTech Connect

    Mitsuhashi, M.; Payan, D.G.

    1987-03-02

    In order to investigate the relationship between the biochemical pathways that characterize contraction and cell growth, the authors have studied both contraction, mitogenesis and protein synthesis induced by the vasoactive neuropeptides, substance P (SP), calcitonin gene related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) on four different established vascular and non-vascular smooth muscle cell lines. Contraction in vitro was evaluated by light microscopy and recorded photographically. Mitogenesis and protein synthesis were evaluated by (/sup 3/H)-thymidine incorporation into cells and (/sup 3/H)-amino acid incorporation into trichloroacetic acid precipitated materials, respectively. SP stimulated mitogenesis of A7r5 cells (embryonic rat aorta), but failed to induce significant contraction of these cells, whereas, SP induced contraction of cultured adult rat vascular smooth muscle cells (VSMC), but failed to stimulate mitogenesis. CGRP and VIP stimulated mitogenesis and protein synthesis, respectively, of DDT/sub 1/MF-2 cells (hamster vas deferens), but neither induced contraction of this cell line. All three neuropeptides showed no effect on BC/sub 3/H1 (mouse smooth muscle-like) cells. These results suggest that neuropeptides with vasoactive properties modulate different stages of cellular mitogenic responses which may be regulated by the degree of maturation of smooth muscle cell. 22 references, 5 figures.

  10. Orai channel-mediated Ca2+ signals in vascular and airway smooth muscle

    PubMed Central

    Spinelli, Amy M.

    2016-01-01

    Orai (Orai1, Orai2, and Orai3) proteins form a family of highly Ca2+-selective plasma membrane channels that are regulated by stromal-interacting molecules (STIM1 and STIM2); STIM proteins are Ca2+ sensors located in the membrane of the endoplasmic reticulum. STIM and Orai proteins are expressed in vascular and airway smooth muscle and constitute the molecular components of the ubiquitous store-operated Ca2+ entry pathway that mediate the Ca2+ release-activated Ca2+ current. STIM/Orai proteins also encode store-independent Ca2+ entry pathways in smooth muscle. Altered expression and function of STIM/Orai proteins have been linked to vascular and airway pathologies, including restenosis, hypertension, and atopic asthma. In this review we discuss our current understanding of Orai proteins and the store-dependent and -independent signaling pathways mediated by these proteins in vascular and airway smooth muscle. We also discuss the current studies linking altered expression and function of Orai proteins with smooth muscle-related pathologies. PMID:26718630

  11. Antibodies probe for folded monomeric myosin in relaxed and contracted smooth muscle.

    PubMed

    Horowitz, A; Trybus, K M; Bowman, D S; Fay, F S

    1994-09-01

    Regulatory light chain phosphorylation is required for assembly of smooth and non-muscle myosins in vitro, but its effect on polymerization within the cell is not understood. Relaxed smooth muscle cells contain dephosphorylated thick filaments, but this does not exclude the presence of a pool of folded myosin monomers which could be recruited to assemble when phosphorylated, thus forming part of smooth muscle's activation pathway. To test this hypothesis, relaxed and contracted avian gizzard cryosections were labeled with a fluorescently conjugated monoclonal antibody specific for the folded monomeric conformation, or with an antibody against the tip of the tail whose epitope is accessible in the monomeric but not the filamentous state. Fluorescence intensity observed in the two physiological states was quantitated by digital imaging microscopy. Only trace amounts of folded monomeric myosin were detected in both the relaxed and contracted states. The amount of monomer also did not increase when alpha-toxin permeabilized gizzard was equilibrated in a solvent that disassembles filaments in vitro. Assembly/disassembly is therefore unlikely to play a major role in regulating the contraction/relaxation cycle in smooth muscle cells.

  12. Migration of bovine aortic smooth muscle cells after wounding injury. The role of hyaluronan and RHAMM.

    PubMed Central

    Savani, R C; Wang, C; Yang, B; Zhang, S; Kinsella, M G; Wight, T N; Stern, R; Nance, D M; Turley, E A

    1995-01-01

    The migration of smooth muscle cells is a critical event in the pathogenesis of vascular diseases. We have investigated the role of hyaluronan (HA) and the hyaluronan receptor RHAMM in the migration of adult bovine aortic smooth muscle cells (BASMC). Cultured BASMC migrated from the leading edge of a single scratch wound with increased velocity between 1 and 24 h. Polyclonal anti-RHAMM antisera that block HA binding with this receptor abolished smooth muscle cell migration following injury. HA stimulated the random locomotion of BASMC and its association with the cell monolayer increased following wounding injury. Immunoblot analysis of wounded monolayers demonstrated a novel RHAMM protein isoform that appeared within one hour after injury. At the time of increased cell motility after wounding, FACS analysis demonstrated an increase in the membrane localization in approximately 25% of the cell population. Confocal microscopy of injured monolayers confirmed that membrane expression of this receptor was limited to cells at the wound edge. Collectively, these data demonstrate that RHAMM is necessary for the migration of smooth muscle cells and that expression and distribution of this receptor is tightly regulated following wounding of BASMC monolayers. Images PMID:7533785

  13. Characterization of vascular smooth muscle cell phenotype in long-term culture.

    PubMed

    Absher, M; Woodcock-Mitchell, J; Mitchell, J; Baldor, L; Low, R; Warshaw, D

    1989-02-01

    Studies of bovine carotid artery smooth muscle cells, during long-term in vitro subcultivation (up to 100 population doublings), have revealed phenotypic heterogeneity among cells, as characterized by differences in proliferative behavior, cell morphology, and contractile-cytoskeletal protein profiles. In vivo, smooth muscle cells were spindle-shaped and expressed desmin and alpha-smooth muscle actin (50% of total actin) as their predominant cytoskeletal and contractile proteins. Within 24 h of culture, vimentin rather than desmin was the predominant intermediate filament protein, with little change in alpha-actin content. Upon initial subcultivation, all cells were flattened and fibroblastic in appearance with a concomitant fivefold reduction in alpha-actin content, whereas the beta and gamma nonmuscle actins predominated. In three out of four cell lines studied, fluctuations in proliferative activity were observed during the life span of the culture. These spontaneous fluctuations in proliferation were accompanied by coordinated changes in morphology and contractile-cytoskeletal protein profiles. During periods of enhanced proliferation a significant proportion of cells reverted to their original spindle-shaped morphology with a simultaneous increase in alpha-actin content (20 to 30% of total actin). These results suggest that in long-term culture smooth muscle cells undergo spontaneous modulations in cell phenotype and may serve as a useful model for studying the regulation of intracellular protein expression.

  14. I-spline Smoothing for Calibrating Predictive Models.

    PubMed

    Wu, Yuan; Jiang, Xiaoqian; Kim, Jihoon; Ohno-Machado, Lucila

    2012-01-01

    We proposed the I-spline Smoothing approach for calibrating predictive models by solving a nonlinear monotone regression problem. We took advantage of I-spline properties to obtain globally optimal solutions while keeping the computational cost low. Numerical studies based on three data sets showed the empirical evidences of I-spline Smoothing in improving calibration (i.e.,1.6x, 1.4x, and 1.4x on the three datasets compared to the average of competitors-Binning, Platt Scaling, Isotonic Regression, Monotone Spline Smoothing, Smooth Isotonic Regression) without deterioration of discrimination.

  15. The Existence of Smooth Densities for the Prediction, Filtering and Smoothing Problems

    DTIC Science & Technology

    1990-12-20

    identify by block number) FIELD GROUP SUB-GROUP Prediction, filtering, smoothing, stochastic control,I adjoint process, minimum principle, minimum risk ...minimize expected risk . Using integration by parts reverse time representations of Jump processes are obtained. These results have applications in, for...optimal control. Martingale representation results to minimize expected risk are described in [14] and [26]. Full details of results obtained during

  16. Smooth Muscle Titin Zq Domain Interaction with the Smooth Muscle α-Actinin Central Rod*

    PubMed Central

    Chi, Richard J.; Simon, Alanna R.; Bienkiewicz, Ewa A.; Felix, Augustine; Keller, Thomas C. S.

    2008-01-01

    Actin-myosin II filament-based contractile structures in striated muscle, smooth muscle, and nonmuscle cells contain the actin filament-cross-linking protein α-actinin. In striated muscle Z-disks, α-actinin interacts with N-terminal domains of titin to provide a structural linkage crucial for the integrity of the sarcomere. We previously discovered a long titin isoform, originally smitin, hereafter sm-titin, in smooth muscle and demonstrated that native sm-titin interacts with C-terminal EF hand region and central rod R2-R3 spectrin-like repeat region sites in α-actinin. Reverse transcription-PCR analysis of RNA from human adult smooth muscles and cultured rat smooth muscle cells and Western blot analysis with a domain-specific antibody presented here revealed that sm-titin contains the titin gene-encoded Zq domain that may bind to the α-actinin R2-R3 central rod domain as well as Z-repeat domains that bind to the EF hand region. We investigated whether the sm-titin Zq domain binds to α-actinin R2 and R3 spectrin repeat-like domain loops that lie in proximity with two-fold symmetry on the surface of the central rod. Mutations in α-actinin R2 and R3 domain loop residues decreased interaction with expressed sm-titin Zq domain in glutathione S-transferase pull-down and solid phase binding assays. Alanine mutation of a region of the Zq domain with high propensity for α-helix formation decreased apparent Zq domain dimer formation and decreased Zq interaction with the α-actinin R2-R3 region in surface plasmon resonance assays. We present a model in which two sm-titin Zq domains interact with each other and with the two R2-R3 sites in the α-actinin central rod. PMID:18519573

  17. Comparison of smoothing methods for the development of a smoothed seismicity model for Alaska and the implications for seismic hazard

    USGS Publications Warehouse

    Moschetti, Morgan P.; Mueller, Charles S.; Boyd, Oliver S.; Petersen, Mark D.

    2014-01-01

    In anticipation of the update of the Alaska seismic hazard maps (ASHMs) by the U. S. Geological Survey, we report progress on the comparison of smoothed seismicity models developed using fixed and adaptive smoothing algorithms, and investigate the sensitivity of seismic hazard to the models. While fault-based sources, such as those for great earthquakes in the Alaska-Aleutian subduction zone and for the ~10 shallow crustal faults within Alaska, dominate the seismic hazard estimates for locations near to the sources, smoothed seismicity rates make important contributions to seismic hazard away from fault-based sources and where knowledge of recurrence and magnitude is not sufficient for use in hazard studies. Recent developments in adaptive smoothing methods and statistical tests for evaluating and comparing rate models prompt us to investigate the appropriateness of adaptive smoothing for the ASHMs. We develop smoothed seismicity models for Alaska using fixed and adaptive smoothing methods and compare the resulting models by calculating and evaluating the joint likelihood test. We use the earthquake catalog, and associated completeness levels, developed for the 2007 ASHM to produce fixed-bandwidth-smoothed models with smoothing distances varying from 10 to 100 km and adaptively smoothed models. Adaptive smoothing follows the method of Helmstetter et al. and defines a unique smoothing distance for each earthquake epicenter from the distance to the nth nearest neighbor. The consequence of the adaptive smoothing methods is to reduce smoothing distances, causing locally increased seismicity rates, where seismicity rates are high and to increase smoothing distances where seismicity is sparse. We follow guidance from previous studies to optimize the neighbor number (n-value) by comparing model likelihood values, which estimate the likelihood that the observed earthquake epicenters from the recent catalog are derived from the smoothed rate models. We compare likelihood

  18. Inhibition of PKCalpha and rhoA translocation in differentiated smooth muscle by a caveolin scaffolding domain peptide.

    PubMed

    Taggart, M J; Leavis, P; Feron, O; Morgan, K G

    2000-07-10

    Receptor-coupled contraction of smooth muscle involves recruitment to the plasma membrane of downstream effector molecules PKCalpha and rhoA but the mechanism of this signal integration is unclear. Caveolins, the principal structural proteins of caveolar plasma membrane invaginations, have been implicated in the organization and regulation of many signal transducing molecules. Thus, using laser scanning confocal immunofluorescent microscopy, we tested the hypothesis that caveolin is involved in smooth muscle signaling by investigating caveolin isoform expression and localization, together with the effect of a peptide inhibitor of caveolin function, in intact differentiated smooth muscle cells. All three main caveolin isoforms were identified in uterine, stomach, and ileal smooth muscles and assumed a predominantly plasma membranous localization in myometrial cells. Cytoplasmic introduction of a peptide corresponding to the caveolin-1 scaffolding domain-an essential region for caveolin interaction with signaling molecules--significantly inhibited agonist-induced translocation of both PKCalpha and rhoA. Translocation was unimpaired by a scrambled peptide and was unaltered in sham-treated cells. The membranous localization of caveolins, and direct inhibition of receptor-coupled PKCalpha and rhoA translocation by the caveolin-1 scaffolding domain, supports the concept that caveolins can regulate the integration of extracellular contractile stimuli and downstream intracellular effectors in smooth muscle.

  19. The Modulation of Potassium Channels in the Smooth Muscle as a Therapeutic Strategy for Disorders of the Gastrointestinal Tract.

    PubMed

    Currò, Diego

    2016-01-01

    Alterations of smooth muscle contractility contribute to the pathophysiology of important functional gastrointestinal disorders (FGIDs) such as functional dyspepsia and irritable bowel syndrome. Consequently, drugs that decrease smooth muscle contractility are effective treatments for these diseases. Smooth muscle contraction is mainly triggered by Ca(2+) influx through voltage-dependent channels located in the plasma membrane. Thus, the modulation of the membrane potential results in the regulation of Ca(2+) influx and cytosolic levels. K(+) channels play fundamental roles in these processes. The open probability of K(+) channels increases in response to various stimuli, including membrane depolarization (voltage-gated K(+) [K(V)] channels) and the increase in cytosolic Ca(2+) levels (Ca(2+)-dependent K(+) [K(Ca)] channels). K(+) channel activation is mostly associated with outward K(+) currents that hyperpolarize the membrane and reduce cell excitability and contractility. In addition, some K(+) channels are open at the resting membrane potential values of the smooth muscle cells in some gut segments and contribute to set the resting membrane potential itself. The closure of these channels induces membrane depolarization and smooth muscle contraction. K(V)1.2, 1.5, 2.2, 4.3, 7.4 and 11.1, K(Ca)1.1 and 2.3, and inwardly rectifying type 6K(+) (K(ir)6) channels play the most important functional roles in the gastrointestinal smooth muscle. Activators of all these channels may theoretically relax the gastrointestinal smooth muscle and could therefore be promising new therapeutic options for FGID. The challenge of future drug research and development in this area will be to synthesize molecules selective for the channel assemblies expressed in the gastrointestinal smooth muscle.

  20. Nuclear fusion-independent smooth muscle differentiation of human adipose-derived stem cells induced by a smooth muscle environment.

    PubMed

    Zhang, Rong; Jack, Gregory S; Rao, Nagesh; Zuk, Patricia; Ignarro, Louis J; Wu, Benjamin; Rodríguez, Larissa V

    2012-03-01

    Human adipose-derived stem cells hASC have been isolated and were shown to have multilineage differentiation capacity. Although both plasticity and cell fusion have been suggested as mechanisms for cell differentiation in vivo, the effect of the local in vivo environment on the differentiation of adipose-derived stem cells has not been evaluated. We previously reported the in vitro capacity of smooth muscle differentiation of these cells. In this study, we evaluate the effect of an in vivo smooth muscle environment in the differentiation of hASC. We studied this by two experimental designs: (a) in vivo evaluation of smooth muscle differentiation of hASC injected into a smooth muscle environment and (b) in vitro evaluation of smooth muscle differentiation capacity of hASC exposed to bladder smooth muscle cells. Our results indicate a time-dependent differentiation of hASC into mature smooth muscle cells when these cells are injected into the smooth musculature of the urinary bladder. Similar findings were seen when the cells were cocultured in vitro with primary bladder smooth muscle cells. Chromosomal analysis demonstrated that microenvironment cues rather than nuclear fusion are responsible for this differentiation. We conclude that cell plasticity is present in hASCs, and their differentiation is accomplished in the absence of nuclear fusion.

  1. Epigenetic Control of Smooth Muscle Cell Identity and Lineage Memory.

    PubMed

    Gomez, Delphine; Swiatlowska, Pamela; Owens, Gary K

    2015-12-01

    Vascular smooth muscle cells (SMCs), like all cells, acquire a cell-specific epigenetic signature during development that includes acquisition of a unique repertoire of histone and DNA modifications. These changes are postulated to induce an open chromatin state (referred to as euchromatin) on the repertoire of genes that are expressed in differentiated SMC, including SMC-selective marker genes like Acta2 and Myh11, as well as housekeeping genes expressed by most cell types. In contrast, genes that are silenced in differentiated SMC acquire modifications associated with a closed chromatin state (ie, heterochromatin) and transcriptional silencing. Herein, we review mechanisms that regulate epigenetic control of the differentiated state of SMC. In addition, we identify some of the major limitations in the field and future challenges, including development of innovative new tools and approaches, for performing single-cell epigenetic assays and locus-selective editing of the epigenome that will allow direct studies of the functional role of specific epigenetic controls during development, injury repair, and disease, including major cardiovascular diseases, such as atherosclerosis, hypertension, and microvascular disease, associated with diabetes mellitus.

  2. Smooth Muscle Hgs Deficiency Leads to Impaired Esophageal Motility

    PubMed Central

    Chen, Jicheng; Hou, Ning; Zhang, Chong; Teng, Yan; Cheng, Xuan; Li, Zhenhua; Ren, Jie; Zeng, Jian; Li, Rui; Wang, Wei; Yang, Xiao; Lan, Yu

    2015-01-01

    As a master component of endosomal sorting complex required for transport proteins, hepatocyte growth factor-regulated tyrosine kinase substrate (Hgs) participates multiple cellular behaviors. However, the physiological role of Hgs in smooth muscle cells (SMCs) is by far unknown. Here we explored the in vivo function of Hgs in SMCs by using a conditional gene knockout strategy. Hgs deficiency in SMCs uniquely led to a progressive dilatation of esophagus with a remarkable thinning muscle layer. Of note, the mutant esophagus showed a decreased contractile responsiveness to potassium chloride and acetylcholine stimulation. Furthermore, an increase in the inhibitory neurites along with an intense infiltration of T lymphocytes in the mucosa and muscle layer were observed. Consistently, Hgs deficiency in SMCs resulted in a disturbed expression of a set of genes involved in neurotrophin and inflammation, suggesting that defective SMC might be a novel source for excessive production of cytokines and chemokines which may trigger the neuronal dysplasia and ultimately contribute to the compromised esophageal motility. The data suggest potential implications in the pathogenesis of related diseases such as gastroesophageal reflux disease. PMID:26078721

  3. Integrability of smooth Wilson loops in N=4 superspace

    NASA Astrophysics Data System (ADS)

    Beisert, Niklas; Müller, Dennis; Plefka, Jan; Vergu, Cristian

    2015-12-01

    We perform a detailed study of the Yangian symmetry of smooth supersymmetric Maldacena-Wilson loops in planar N=4 super Yang-Mills theory. This hidden symmetry extends the global superconformal symmetry present for these observables. A gauge-covariant action of the Yangian generators on the Wilson line is established that generalizes previous constructions built upon path variations. Employing these generators the Yangian symmetry is proven for general paths in non-chiral N=4 superspace at the first perturbative order. The bi-local piece of the level-one generators requires the use of a regulator due to divergences in the coincidence limit. We perform regularization by point splitting in detail, thereby constructing additional local and boundary contributions as regularization for all level-one Yangian generators. Moreover, the Yangian algebra at level one is checked and compatibility with local kappa-symmetry is established. Finally, the consistency of the Yangian symmetry is shown to depend on two properties: the vanishing of the dual Coxeter number of the underlying superconformal algebra and the existence of a novel superspace "G-identity" for the gauge field theory. This tightly constrains the conformal gauge theories to which integrability can possibly apply.

  4. Smooth cubic commensurate oxides on gallium nitride

    SciTech Connect

    Paisley, Elizabeth A.; Gaddy, Benjamin E.; LeBeau, James M.; Shelton, Christopher T.; Losego, Mark D.; Mita, Seiji; Collazo, Ramón; Sitar, Zlatko; Irving, Douglas L.; Maria, Jon-Paul; Biegalski, Michael D.; Christen, Hans M.

    2014-02-14

    Smooth, commensurate alloys of 〈111〉-oriented Mg{sub 0.52}Ca{sub 0.48}O (MCO) thin films are demonstrated on Ga-polar, c+ [0001]-oriented GaN by surfactant-assisted molecular beam epitaxy and pulsed laser deposition. These are unique examples of coherent cubic oxide|nitride interfaces with structural and morphological perfection. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly 100× reduction in leakage current density for the surfactant-assisted samples. HAADF-STEM images of the MCO|GaN interface show commensurate alignment of atomic planes with minimal defects due to lattice mismatch. STEM and DFT calculations show that GaN c/2 steps create incoherent boundaries in MCO over layers which manifest as two in-plane rotations and determine consequently the density of structural defects in otherwise coherent MCO. This new understanding of interfacial steps between HCP and FCC crystals identifies the steps needed to create globally defect-free heterostructures.

  5. Neuroeffector apparatus in gastrointestinal smooth muscle organs.

    PubMed

    Sanders, Kenton M; Hwang, Sung Jin; Ward, Sean M

    2010-12-01

    Control of gastrointestinal (GI) movements by enteric motoneurons is critical for orderly processing of food, absorption of nutrients and elimination of wastes. Work over the past several years has suggested that motor neurotransmission is more complicated than simple release of transmitter from nerve terminals and binding of receptors on smooth muscle cells. In fact the 'neuro-effector' junction in the tunica muscularis might consist of synaptic-like connectivity with specialized cells, and contributions from multiple cell types in integrated post-junctional responses. Interstitial cells of Cajal (ICC) were proposed as potential mediators in motor neurotransmission based on reduced post-junctional responses observed in W mutants that have reduced populations of ICC. More recent studies on W mutants have contradicted the original findings, and suggested that ICC may not be significant players in motor neurotransmission. This review examines the evidence for and against the role of ICC in motor neurotransmission and outlines areas for additional investigation that would help further resolve this controversy.

  6. A Smoothed Particle Hydrodynamics approach for poroelasticity

    NASA Astrophysics Data System (ADS)

    Osorno, Maria; Steeb, Holger

    2016-04-01

    Within the framework of the SHynergie project we look to investigate hydraulic fracturing and crack evolving in poroelastic media. We model biphasic media assuming incompressible solid grain and incompressible pore liquid. Modeling evolving fractures and fracture networks in elastic and poroelastic media by mesh-based numerical approaches, like X-FEM, is especially in 3-dim a challenging task. Therefore, we propose a meshless particle method for fractured media based on the Smoothed Particle Hydrodynamics (SPH) approach. SPH is a meshless Lagrangian method highly suitable for the simulation of large deformations including free surfaces and/or interfaces. Within the SPH method, the computational domain is discretized with particles, avoiding the computational expenses of meshing. Our SPH solution is implemented in a parallel computational framework, which allows to simulate large domains more representative of the scale of our study cases. Our implementation is carefully validated against classical mesh-based approaches and compared with classical solutions for consolidation problems. Furthermore, we discuss fracture initiation and propagation in poroelastic rocks at the reservoir scale.

  7. An implicit Smooth Particle Hydrodynamic code

    SciTech Connect

    Knapp, Charles E.

    2000-05-01

    An implicit version of the Smooth Particle Hydrodynamic (SPH) code SPHINX has been written and is working. In conjunction with the SPHINX code the new implicit code models fluids and solids under a wide range of conditions. SPH codes are Lagrangian, meshless and use particles to model the fluids and solids. The implicit code makes use of the Krylov iterative techniques for solving large linear-systems and a Newton-Raphson method for non-linear corrections. It uses numerical derivatives to construct the Jacobian matrix. It uses sparse techniques to save on memory storage and to reduce the amount of computation. It is believed that this is the first implicit SPH code to use Newton-Krylov techniques, and is also the first implicit SPH code to model solids. A description of SPH and the techniques used in the implicit code are presented. Then, the results of a number of tests cases are discussed, which include a shock tube problem, a Rayleigh-Taylor problem, a breaking dam problem, and a single jet of gas problem. The results are shown to be in very good agreement with analytic solutions, experimental results, and the explicit SPHINX code. In the case of the single jet of gas case it has been demonstrated that the implicit code can do a problem in much shorter time than the explicit code. The problem was, however, very unphysical, but it does demonstrate the potential of the implicit code. It is a first step toward a useful implicit SPH code.

  8. Smoothed particle hydrodynamics with GRAPE-1A

    NASA Technical Reports Server (NTRS)

    Umemura, Masayuki; Fukushige, Toshiyuki; Makino, Junichiro; Ebisuzaki, Toshikazu; Sugimoto, Daiichiro; Turner, Edwin L.; Loeb, Abraham

    1993-01-01

    We describe the implementation of a smoothed particle hydrodynamics (SPH) scheme using GRAPE-1A, a special-purpose processor used for gravitational N-body simulations. The GRAPE-1A calculates the gravitational force exerted on a particle from all other particles in a system, while simultaneously making a list of the nearest neighbors of the particle. It is found that GRAPE-1A accelerates SPH calculations by direct summation by about two orders of magnitudes for a ten thousand-particle simulation. The effective speed is 80 Mflops, which is about 30 percent of the peak speed of GRAPE-1A. Also, in order to investigate the accuracy of GRAPE-SPH, some test simulations were executed. We found that the force and position errors are smaller than those due to representing a fluid by a finite number of particles. The total energy and momentum were conserved within 0.2-0.4 percent and 2-5 x 10 exp -5, respectively, in simulations with several thousand particles. We conclude that GRAPE-SPH is quite effective and sufficiently accurate for self-gravitating hydrodynamics.

  9. Immortalization of primary human smooth muscle cells.

    PubMed Central

    Perez-Reyes, N; Halbert, C L; Smith, P P; Benditt, E P; McDougall, J K

    1992-01-01

    Primary human aortic and myometrial smooth muscle cells (SMCs) were immortalized using an amphotropic recombinant retroviral construct containing the E6 and E7 open reading frames (ORFs) of human papillomavirus type 16. The SMCs expressing the E6/E7 ORFs have considerably elevated growth rates when compared with nonimmortalized control cells and show no signs of senescence with long-term passage. The first SMC line derived in this study has been maintained in continuous tissue culture for greater than 1 year (greater than 180 population doublings). The immortalized SMCs have decreased cell size and decreased content of muscle-specific alpha-actin filaments as determined by indirect immunofluorescence. Southern blot analysis has demonstrated the stable integration of the E6/E7 ORFs in the retrovirally infected cells, and radioimmunoprecipitation has confirmed the continued expression of the E6 and E7 genes. Cytogenetic studies of the SMC lines have revealed essentially diploid populations except for the myometrial clonal line, which became aneuploid at late passage (greater than 125 doublings). These cell lines were not tumorigenic in nude mice. Images PMID:1311088

  10. Drop splash on a smooth, dry surface

    NASA Astrophysics Data System (ADS)

    Riboux, Guillaume; Gordillo, Jose Manuel; Korobkin, Alexander

    2013-11-01

    It is our purpose here to determine the conditions under which a drop of a given liquid with a known radius R impacting against a smooth impermeable surface at a velocity V, will either spread axisymmetrically onto the substrate or will create a splash, giving rise to usually undesired star-shaped patterns. In our experimental setup, drops are generated injecting low viscosity liquids falling under the action of gravity from a stainless steel hypodermic needle. The experimental observations using two high speed cameras operating simultaneously and placed perpendicularly to each other reveal that, initially, the drop deforms axisymmetrically, with A (T) the radius of the wetted area. For high enough values of the drop impact velocity, a thin sheet of liquid starts to be ejected from A (T) at a velocity Vjet > V for instants of time such that T >=Tc . If Vjet is above a certain threshold, which depends on the solid wetting properties as well as on the material properties of both the liquid and the atmospheric gas, the rim of the lamella dewets the solid to finally break into drops. Using Wagner's theory we demonstrate that A (T) =√{ 3 RVT } and our results also reveal that Tc We - 1 / 2 =(ρV2 R / σ) - 1 / 2 and Vjet We 1 / 4 .

  11. Hidden Degeneracies in Piecewise Smooth Dynamical Systems

    NASA Astrophysics Data System (ADS)

    Jeffrey, Mike R.

    When a flow suffers a discontinuity in its vector field at some switching surface, the flow can cross through or slide along the surface. Sliding along the switching surface can be understood as the flow along an invariant manifold inside a switching layer. It turns out that the usual method for finding sliding modes — the Filippov convex combination or Utkin equivalent control — results in a degeneracy in the switching layer whenever the flow is tangent to the switching surface from both sides. We derive the general result and analyze the simplest case here, where the flow curves parabolically on either side of the switching surface (the so-called fold-fold or two-fold singularities). The result is a set of zeros of the fast switching flow inside the layer, which is structurally unstable to perturbation by terms nonlinear in the switching parameter, terms such as (signx)2 [where the superscript does mean “squared”]. We provide structurally stable forms, and show that in this form the layer system is equivalent to a generic singularity of a two timescale system. Finally we show that the same degeneracy arises when a discontinuity is smoothed using standard regularization methods.

  12. Involvement of the central thalamus in the control of smooth pursuit eye movements.

    PubMed

    Tanaka, Masaki

    2005-06-22

    During maintenance of smooth pursuit eye movements, the brain must keep track of pursuit velocity to reconstruct target velocity from motion of retinal images. Although a recent study showed that corollary discharge signals through the thalamus to the cortex are used for internal monitoring of saccades, it remains unknown whether signals in the thalamus also contribute to monitoring and on-line regulation of smooth pursuit. The present study sought possible roles of the thalamocortical pathways in pursuit by recording activities of single thalamic neurons and by analyzing the effects of local inactivation. Data showed that many neurons in the ventrolateral thalamus exhibited directional modulation during pursuit. Most neurons discharged before or during initiation of pursuit, and the firing rate was proportional to the speed of target motion in a preferred direction. When the tracking target was extinguished briefly during maintenance of pursuit, these neurons continued firing, indicating that they carried extra-retinal, eye movement signals. The majority of neurons showed no change in activity around the time of small catch-up saccades during pursuit but responded transiently to large (16 degrees) memory-guided saccades in the preferred pursuit direction. Local inactivation of the recording sites did not alter pursuit latency but reduced eye velocity modestly during initiation and maintenance of ipsiversive pursuit. The results suggest that the central thalamus lies within pathways that regulate and monitor smooth pursuit eye movements.

  13. Troglitazone inhibits vascular smooth muscle cell growth and intimal hyperplasia.

    PubMed Central

    Law, R E; Meehan, W P; Xi, X P; Graf, K; Wuthrich, D A; Coats, W; Faxon, D; Hsueh, W A

    1996-01-01

    Vascular smooth muscle cell (VSMC) proliferation and migration are responses to arterial injury that are highly important to the processes of restenosis and atherosclerosis. In the arterial balloon injury model in the rat, platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) are induced in the vessel wall and regulate these VSMC activities. Novel insulin sensitizing agents, thiazolidinediones, have been demonstrated to inhibit insulin and epidermal growth factor-induced growth of VSMCs. We hypothesized that these agents might also inhibit the effect of PDGF and bFGF on cultured VSMCs and intimal hyperplasia in vivo. Troglitazone (1 microM), a member of the thiazolidinedione class, produced a near complete inhibition of both bFGF-induced DNA synthesis as measured by bromodeoxyuridine incorporation (6.5+/-3.9 vs. 17.6+/-4.3% cells labeled, P < 0.05) and c-fos induction. This effect was associated with an inhibition (by 73+/-4%, P < 0.01) by troglitazone of the transactivation of the serum response element, which regulates c-fos expression. Inhibition of c-fos induction by troglitazone appeared to occur via a blockade of the MAP kinase pathway at a point downstream of MAP kinase activation by MAP kinase kinase. At this dose, troglitazone also inhibited PDGF-BB-directed migration of VSMC (by 70+/-6%, P < 0.01). These in vitro effects were operative in vivo. Quantitative image analysis revealed that troglitazone-treated rats had 62% (P < 0.001) less neointima/media area ratio 14 d after balloon injury of the aorta compared with injured rats that received no troglitazone. These results suggest troglitazone is a potent inhibitor of VSMC proliferation and migration and, thus, may be a useful agent to prevent restenosis and possibly atherosclerosis. PMID:8878442

  14. Neurophysiology and Neuroanatomy of Smooth Pursuit: Lesion Studies

    ERIC Educational Resources Information Center

    Sharpe, James A.

    2008-01-01

    Smooth pursuit impairment is recognized clinically by the presence of saccadic tracking of a small object and quantified by reduction in pursuit gain, the ratio of smooth eye movement velocity to the velocity of a foveal target. Correlation of the site of brain lesions, identified by imaging or neuropathological examination, with defective smooth…

  15. Cognitive Processes Involved in Smooth Pursuit Eye Movements

    ERIC Educational Resources Information Center

    Barnes, G. R.

    2008-01-01

    Ocular pursuit movements allow moving objects to be tracked with a combination of smooth movements and saccades. The principal objective is to maintain smooth eye velocity close to object velocity, thus minimising retinal image motion and maintaining acuity. Saccadic movements serve to realign the image if it falls outside the fovea, the area of…

  16. Immunohistochemical and functional studies on calcium-sensing receptors in rat uterine smooth muscle.

    PubMed

    Pistilli, Marc J; Petrik, James J; Holloway, Alison C; Crankshaw, Denis J

    2012-01-01

    1. Activation of calcium-sensing receptors (CaS) leads to relaxation of vascular smooth muscle. However, the role of CaS in uterine smooth muscle is unknown. Therefore the aim of the present study was to investigate the expression and function of CaS in the uterus. 2. The expression of CaS in the oestrogen-dominated rat uterus was investigated using immunohistochemistry. The effects of putative CaS ligands on oxytocin-induced contractions of longitudinally orientated uterine strips from oestrogen-dominated rats were determined at reduced extracellular Ca²⁺ concentrations using conventional organ bath techniques. 3. Immunohistochemical evidence showed the presence of CaS in the endometrium and smooth muscle layers of the rat uterus. Oxytocin-induced contractions were inhibited by cations (Gd³⁺ > Ca²⁺ = Mg²⁺), polyamines (spermine > spermidine) and the positive allosteric modulators cinacalcet and calindol. However (R)- and (S)-cinacalcet were equipotent, indicating a lack of stereoselectivity, and the negative allosteric modulator calhex-231 also caused dose-dependent relaxation. In addition, although intermediate-conductance calcium-activated potassium channels and cytochrome P450-dependent signal transduction have been implicated in CaS-induced relaxation of vascular smooth muscle, neither Tram-34 nor miconazole (1 μmol/L), which block these pathways, respectively, had any effect on the ability of cinacalcet to inhibit oxytocin-induced contractions. 4. Calcium-sensing receptors are expressed in smooth muscle layers of the rat uterus and their ligands produce potent relaxation of longitudinally orientated uterine strips. However, the pharmacological profile of inhibition of contractility by CaS ligands is not consistent with a role for CaS in the regulation of uterine contractility in the rat.

  17. Increased IGF-IEc expression and mechano-growth factor production in intestinal muscle of fibrostenotic Crohn's disease and smooth muscle hypertrophy.

    PubMed

    Li, Chao; Vu, Kent; Hazelgrove, Krystina; Kuemmerle, John F

    2015-12-01

    The igf1 gene is alternatively spliced as IGF-IEa and IGF-IEc variants in humans. In fibrostenotic Crohn's disease, the fibrogenic cytokine TGF-β1 induces IGF-IEa expression and IGF-I production in intestinal smooth muscle and results in muscle hyperplasia and collagen I production that contribute to stricture formation. Mechano-growth factor (MGF) derived from IGF-IEc induces skeletal and cardiac muscle hypertrophy following stress. We hypothesized that increased IGF-IEc expression and MGF production mediated smooth muscle hypertrophy also characteristic of fibrostenotic Crohn's disease. IGF-IEc transcripts and MGF protein were increased in muscle cells isolated from fibrostenotic intestine under regulation by endogenous TGF-β1. Erk5 and MEF2C were phosphorylated in vivo in fibrostenotic muscle; both were phosphorylated and colocalized to nucleus in response to synthetic MGF in vitro. Smooth muscle-specific protein expression of α-smooth muscle actin, γ-smooth muscle actin, and smoothelin was increased in affected intestine. Erk5 inhibition or MEF2C siRNA blocked smooth muscle-specific gene expression and hypertrophy induced by synthetic MGF. Conditioned media of cultured fibrostenotic muscle induced muscle hypertrophy that was inhibited by immunoneutralization of endogenous MGF or pro-IGF-IEc. The results indicate that TGF-β1-dependent IGF-IEc expression and MGF production in patients with fibrostenotic Crohn's disease regulates smooth muscle cell hypertrophy a critical factor that contributes to intestinal stricture formation.

  18. Regeneration and Maintenance of Intestinal Smooth Muscle Phenotypes

    NASA Astrophysics Data System (ADS)

    Walthers, Christopher M.

    Tissue engineering is an emerging field of biomedical engineering that involves growing artificial organs to replace those lost to disease or injury. Within tissue engineering, there is a demand for artificial smooth muscle to repair tissues of the digestive tract, bladder, and vascular systems. Attempts to develop engineered smooth muscle tissues capable of contracting with sufficient strength to be clinically relevant have so far proven unsatisfactory. The goal of this research was to develop and sustain mature, contractile smooth muscle. Survival of implanted SMCs is critical to sustain the benefits of engineered smooth muscle. Survival of implanted smooth muscle cells was studied with layered, electrospun polycaprolactone implants with lasercut holes ranging from 0--25% porosity. It was found that greater angiogenesis was associated with increased survival of implanted cells, with a large increase at a threshold between 20% and 25% porosity. Heparan sulfate coatings improved the speed of blood vessel infiltration after 14 days of implantation. With these considerations, thicker engineered tissues may be possible. An improved smooth muscle tissue culture technique was utilized. Contracting smooth muscle was produced in culture by maintaining the native smooth muscle tissue organization, specifically by sustaining intact smooth muscle strips rather than dissociating tissue in to isolated smooth muscle cells. Isolated cells showed a decrease in maturity and contained fewer enteric neural and glial cells. Muscle strips also exhibited periodic contraction and regular fluctuation of intracellular calclium. The muscle strip maturity persisted after implantation in omentum for 14 days on polycaprolactone scaffolds. A low-cost, disposable bioreactor was developed to further improve maturity of cultured smooth muscle cells in an environment of controlled cyclical stress.The bioreactor consistently applied repeated mechanical strain with controllable inputs for strain

  19. Crystal Structure of a Phosphorylated Light Chain Domain of Scallop Smooth-Muscle Myosin

    SciTech Connect

    Kumar, V.S.; Robinson, H.; O-Neall-Hennessey, E.; Reshetnikova, L.; Brown, J. H.; Szent-Gyorgyi, A. G.; Cohen, C.

    2011-11-02

    We have determined the crystal structure of a phosphorylated smooth-muscle myosin light chain domain (LCD). This reconstituted LCD is of a sea scallop catch muscle myosin with its phosphorylatable regulatory light chain (RLC SmoA). In the crystal structure, Arg{sup 16}, an arginine residue that is present in this isoform but not in vertebrate smooth-muscle RLC, stabilizes the phosphorylation site. This arginine interacts with the carbonyl group of the phosphorylation-site serine in the unphosphorylated LCD (determined previously), and with the phosphate group when the serine is phosphorylated. However, the overall conformation of the LCD is essentially unchanged upon phosphorylation. This result provides additional evidence that phosphorylation of the RLC is unlikely to act as an on-switch in regulation of scallop catch muscle myosin.

  20. Anoctamins and gastrointestinal smooth muscle excitability.

    PubMed

    Sanders, Kenton M; Zhu, Mei Hong; Britton, Fiona; Koh, Sang Don; Ward, Sean M

    2012-02-01

    Interstitial cells of Cajal (ICC) generate electrical pacemaker activity in gastrointestinal smooth muscles. We investigated whether Tmem16a, which encodes anoctamin 1 (ANO1), a Ca(2+)-activated Cl(-) channel, might be involved in pacemaker activity in ICC. The Tmem16a transcripts and ANO1 were expressed robustly in GI muscles, specifically in ICC in murine, non-human primate (Macaca fascicularis) and human GI tracts. Splice variants of Tmem16a, as well as other paralogues of the Tmem16 family, were expressed in gastrointestinal muscles. Calcium-activated Cl(-) channel blocking drugs, niflumic acid and DIDS blocked slow waves in intact muscles of mouse, primate and human small intestine and stomach. Slow waves failed to develop in Tmem16a knock-out mice (Tmem16a(tm1Bdh/tm1Bdh)). The pacemaker mechanism was investigated in isolated ICC from transgenic mice with constitutive expression of copepod super green fluorescent protein (copGFP). Depolarization of ICC activated inward currents due to a Cl(-)-selective conductance. Removal of extracellular Ca(2+), replacement of Ca(2+) with Ba(2+), or extracellular Ni(2+) (30 μM) blocked the inward current. Single Ca(2+)-activated Cl(-) channels with a unitary conductance of 7.8 pS were resolved in excised patches from ICC. The inward current was blocked in a concentration-dependent manner by niflumic acid (IC(50) = 4.8 μM). The role of ANO1 in cholinergic responses in ICC was also investigated. Carbachol activated Ca(2+)-activated Cl(-) currents in ICC, and responses to cholinergic nerve stimulation were blocked by niflumic acid in intact muscles. Anoctamin 1 is a prominent conductance in ICC, and these channels appear to be involved in pacemaker activity and in responses to enteric excitatory neurotransmitters.

  1. Neptune's Orbital Migration Was Grainy, Not Smooth

    NASA Astrophysics Data System (ADS)

    Nesvorný, David; Vokrouhlický, David

    2016-07-01

    The Kuiper Belt is a population of icy bodies beyond the orbit of Neptune. The complex orbital structure of the Kuiper Belt, including several categories of objects inside and outside of resonances with Neptune, emerged as a result of Neptune’s migration into an outer planetesimal disk. An outstanding problem with the existing migration models is that they invariably predict excessively large resonant populations, while observations show that the non-resonant orbits are in fact common (e.g., the main belt population is ≃2-4 times larger than Plutinos in the 3:2 resonance). Here we show that this problem can be resolved if it is assumed that Neptune’s migration was grainy, as expected from scattering encounters of Neptune with massive planetesimals. The grainy migration acts to destabilize resonant bodies with large libration amplitudes, a fraction of which ends up on stable non-resonant orbits. Thus, the non-resonant-to-resonant ratio obtained with the grainy migration is higher, up to ˜10 times higher for the range of parameters investigated here, than in a model with smooth migration. In addition, the grainy migration leads to a narrower distribution of the libration amplitudes in the 3:2 resonance. The best fit to observations is obtained when it is assumed that the outer planetesimal disk below 30 au contained 1000-4000 Plutos. We estimate that the combined mass of Pluto-class objects in the original disk represented 10%-40% of the estimated disk mass ({M}{{disk}}≃ 20 {M}{{Earth}}). This constraint can be used to better understand the accretion processes in the outer solar system.

  2. Computer programs for smoothing and scaling airfoil coordinates

    NASA Technical Reports Server (NTRS)

    Morgan, H. L., Jr.

    1983-01-01

    Detailed descriptions are given of the theoretical methods and associated computer codes of a program to smooth and a program to scale arbitrary airfoil coordinates. The smoothing program utilizes both least-squares polynomial and least-squares cubic spline techniques to smooth interatively the second derivatives of the y-axis airfoil coordinates with respect to a transformed x-axis system which unwraps the airfoil and stretches the nose and trailing-edge regions. The corresponding smooth airfoil coordinates are then determined by solving a tridiagonal matrix of simultaneous cubic-spline equations relating the y-axis coordinates and their corresponding second derivatives. A technique for computing the camber and thickness distribution of the smoothed airfoil is also discussed. The scaling program can then be used to scale the thickness distribution generated by the smoothing program to a specific maximum thickness which is then combined with the camber distribution to obtain the final scaled airfoil contour. Computer listings of the smoothing and scaling programs are included.

  3. AnL1 smoothing spline algorithm with cross validation

    NASA Astrophysics Data System (ADS)

    Bosworth, Ken W.; Lall, Upmanu

    1993-08-01

    We propose an algorithm for the computation ofL1 (LAD) smoothing splines in the spacesWM(D), with . We assume one is given data of the formyiD(f(ti) +ɛi, iD1,...,N with {itti}iD1N ⊂D, theɛi are errors withE(ɛi)D0, andf is assumed to be inWM. The LAD smoothing spline, for fixed smoothing parameterλ?;0, is defined as the solution,sλ, of the optimization problem (1/N)∑iD1N yi-g(ti +λJM(g), whereJM(g) is the seminorm consisting of the sum of the squaredL2 norms of theMth partial derivatives ofg. Such an LAD smoothing spline,sλ, would be expected to give robust smoothed estimates off in situations where theɛi are from a distribution with heavy tails. The solution to such a problem is a "thin plate spline" of known form. An algorithm for computingsλ is given which is based on considering a sequence of quadratic programming problems whose structure is guided by the optimality conditions for the above convex minimization problem, and which are solved readily, if a good initial point is available. The "data driven" selection of the smoothing parameter is achieved by minimizing aCV(λ) score of the form .The combined LAD-CV smoothing spline algorithm is a continuation scheme in λ↘0 taken on the above SQPs parametrized inλ, with the optimal smoothing parameter taken to be that value ofλ at which theCV(λ) score first begins to increase. The feasibility of constructing the LAD-CV smoothing spline is illustrated by an application to a problem in environment data interpretation.

  4. Tobacco constituents are mitogenic for arterial smooth-muscle cells

    SciTech Connect

    Becker, C.G.; Hajjar, D.P.; Hefton, J.M.

    1985-07-01

    Tobacco glycoprotein (TGP) purified from flue-cured tobacco leaves, tar-derived material (TAR), the water soluble, nondialyzable, delipidized extract of cigarette smoke condensate, rutin-bovine serum albumin conjugates, quercetin, and chlorogenic acid are mitogenic for bovine aortic smooth-muscle cells, but not adventitial fibroblasts. The mitogenicity appears to depend on polyphenol epitopes on carrier molecules. Ellagic acid, another plant polyphenol, inhibited arterial smooth-muscle proliferation. These results suggest that a number of ubiquitous, plant-derived substances may influence smooth-muscle cell proliferation in the arterial wall.

  5. Smooth Potential Chaos and N-Body Simulations

    NASA Astrophysics Data System (ADS)

    Kandrup, Henry E.; Sideris, Ioannis V.

    2003-03-01

    Integrations in fixed N-body realizations of smooth density distributions corresponding to a chaotic galactic potential can be used to derive reliable estimates of the largest (finite-time) Lyapunov exponent χS associated with an orbit in the smooth potential generated from the same initial condition, even though the N-body orbit is typically characterized by an N-body exponent χN>>χS. This can be accomplished by either comparing initially nearby orbits in a single N-body system or tracking orbits with the same initial condition evolved in two different N-body realizations of the same smooth density.

  6. Smooth solutions of the Navier-Stokes equations

    SciTech Connect

    Pokhozhaev, S I

    2014-02-28

    We consider smooth solutions of the Cauchy problem for the Navier-Stokes equations on the scale of smooth functions which are periodic with respect to x∈R{sup 3}. We obtain existence theorems for global (with respect to t>0) and local solutions of the Cauchy problem. The statements of these depend on the smoothness and the norm of the initial vector function. Upper bounds for the behaviour of solutions in both classes, which depend on t, are also obtained. Bibliography: 10 titles.

  7. Effect of oxidative stress on the expression of thin filament-associated proteins in gastric smooth muscle cells.

    PubMed

    Al-Shboul, Othman Abdullah; Mustafa, Ayman; Mohammad, Mukhallad; Al-Shehabat, Mustafa; Yousef, Asmaa; Al-Hashimi, Farah

    2014-09-01

    Thin filament-associated proteins such as calponin, caldesmon, and smoothelin are believed to regulate acto-myosin interaction and thus, muscle contraction. Oxidative stress has been found to affect the normal contractile behavior of smooth muscle and is involved in the pathogenesis of a number of human diseases such as diabetes mellitus, hypertension, and atherosclerosis. However, very little is known about the effect of oxidative stress on the expression of smooth muscle contractile proteins. The aim of the current study is to investigate the effect of oxidative stress on the expression of thin filament-associated proteins in rat gastric smooth muscle. Single smooth muscle cells of the stomach obtained from Sprague-Dawley rats were used. Muscle cells were treated with hydrogen peroxide (H2O2) (500 μM) for 30 min or the peroxynitrite donor 3-morpholinosydnonimine (SIN-1) (1 mM) for 90 min to induce oxidative stress. Calponin, caldesmon, and smoothelin expressions were measured via specifically designed enzyme-linked immunosorbent assay. We found that exposure to exogenous H2O2 or incubation of dispersed gastric muscle cells with SIN-1 significantly increased the expression of calponin, caldesmon, and smoothelin proteins. In conclusion: oxidative stress increases the expression of thin filament-associated proteins in gastric smooth muscle, suggesting an important role in gastrointestinal motility disorders associated with oxidative stress.

  8. Transforming growth factor type beta specifically stimulates synthesis of proteoglycan in human adult arterial smooth muscle cells.

    PubMed Central

    Chen, J K; Hoshi, H; McKeehan, W L

    1987-01-01

    Myo-intimal proteoglycan metabolism is thought to be important in blood vessel homeostasis, blood clotting, atherogenesis, and atherosclerosis. Human platelet-derived transforming growth factor type beta (TGF-beta) specifically stimulated synthesis of at least two types of chondroitin sulfate proteoglycans in nonproliferating human adult arterial smooth muscle cells in culture. Stimulation of smooth muscle cell proteoglycan synthesis by smooth muscle cell growth promoters (epidermal growth factor, platelet-derived growth factor, and heparin-binding growth factors) was less than 20% of that elicited by TGF-beta. TGF-beta neither significantly stimulated proliferation of quiescent smooth muscle cells nor inhibited proliferating cells. The extent of TGF-beta stimulation of smooth muscle cell proteoglycan synthesis was similar in both nonproliferating and growth-stimulated cells. TGF-beta, which is a reversible inhibitor of endothelial cell proliferation, had no comparable effect on endothelial cell proteoglycan synthesis. These results are consistent with the hypothesis that TGF-beta is a cell-type-specific regulator of proteoglycan synthesis in human blood vessels and may contribute to the myo-intimal accumulation of proteoglycan in atherosclerotic lesions. Images PMID:3474655

  9. Regional Blood Flow in the Normal and Ischemic Brain Is Controlled by Arteriolar Smooth Muscle Cell Contractility and Not by Capillary Pericytes.

    PubMed

    Hill, Robert A; Tong, Lei; Yuan, Peng; Murikinati, Sasidhar; Gupta, Shobhana; Grutzendler, Jaime

    2015-07-01

    The precise regulation of cerebral blood flow is critical for normal brain function, and its disruption underlies many neuropathologies. The extent to which smooth muscle-covered arterioles or pericyte-covered capillaries control vasomotion during neurovascular coupling remains controversial. We found that capillary pericytes in mice and humans do not express smooth muscle actin and are morphologically and functionally distinct from adjacent precapillary smooth muscle cells (SMCs). Using optical imaging we investigated blood flow regulation at various sites on the vascular tree in living mice. Optogenetic, whisker stimulation, or cortical spreading depolarization caused microvascular diameter or flow changes in SMC but not pericyte-covered microvessels. During early stages of brain ischemia, transient SMC but not pericyte constrictions were a major cause of hypoperfusion leading to thrombosis and distal microvascular occlusions. Thus, capillary pericytes are not contractile, and regulation of cerebral blood flow in physiological and pathological conditions is mediated by arteriolar SMCs.

  10. 7 CFR 51.772 - Fairly smooth texture.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... texture. Fairly smooth texture means that the skin is fairly thin and not coarse for the variety and size of the fruit. “Fairly thin” means that the skin thickness does not average more than 1/2 inch...

  11. Restoration of noisy blurred images by a smoothing spline filter.

    PubMed

    Peyrovian, M J; Sawchuk, A A

    1977-12-01

    For the restoration of noisy blurred images, a controllable smoothing criterion based on the locally variable statistics and minimization of the second derivative is defined, and the corresponding filter, applicable to both space-variant and space-invariant degradations, is obtained. The output of this filter is a cubic spline function. The parameters of the filter determine the local smoothing window and over-all extent of smoothing, and thus the tradeoff between resolution and smoothing is controllable in a spatially nonstationary manner. The interesting properties of this filter have made it capable of restoring signal-dependent noisy images, and it has been successfully applied for filtering images degraded by film-grain noise. Since the matrices of this filter are banded circulant or Toeplitz, efficient algorithms are used for matrix manipulations.

  12. 7 CFR 51.772 - Fairly smooth texture.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... texture. Fairly smooth texture means that the skin is fairly thin and not coarse for the variety and size of the fruit. “Fairly thin” means that the skin thickness does not average more than 1/2 inch...

  13. Smooth local subspace projection for nonlinear noise reduction

    SciTech Connect

    Chelidze, David

    2014-03-15

    Many nonlinear or chaotic time series exhibit an innate broad spectrum, which makes noise reduction difficult. Local projective noise reduction is one of the most effective tools. It is based on proper orthogonal decomposition (POD) and works for both map-like and continuously sampled time series. However, POD only looks at geometrical or topological properties of data and does not take into account the temporal characteristics of time series. Here, we present a new smooth projective noise reduction method. It uses smooth orthogonal decomposition (SOD) of bundles of reconstructed short-time trajectory strands to identify smooth local subspaces. Restricting trajectories to these subspaces imposes temporal smoothness on the filtered time series. It is shown that SOD-based noise reduction significantly outperforms the POD-based method for continuously sampled noisy time series.

  14. Nonparametric Model of Smooth Muscle Force Production During Electrical Stimulation.

    PubMed

    Cole, Marc; Eikenberry, Steffen; Kato, Takahide; Sandler, Roman A; Yamashiro, Stanley M; Marmarelis, Vasilis Z

    2017-03-01

    A nonparametric model of smooth muscle tension response to electrical stimulation was estimated using the Laguerre expansion technique of nonlinear system kernel estimation. The experimental data consisted of force responses of smooth muscle to energy-matched alternating single pulse and burst current stimuli. The burst stimuli led to at least a 10-fold increase in peak force in smooth muscle from Mytilus edulis, despite the constant energy constraint. A linear model did not fit the data. However, a second-order model fit the data accurately, so the higher-order models were not required to fit the data. Results showed that smooth muscle force response is not linearly related to the stimulation power.

  15. Construction of spline functions in spreadsheets to smooth experimental data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A previous manuscript detailed how spreadsheet software can be programmed to smooth experimental data via cubic splines. This addendum corrects a few errors in the previous manuscript and provides additional necessary programming steps. ...

  16. Optimal smoothing of site-energy distributions from adsorption isotherms

    SciTech Connect

    Brown, L.F.; Travis, B.J.

    1983-01-01

    The equation for the adsorption isotherm on a heterogeneous surface is a Fredholm integral equation. In solving it for the site-energy distribution (SED), some sort of smoothing must be carried out. The optimal amount of smoothing will give the most information that is possible without introducing nonexistent structure into the SED. Recently, Butler, Reeds, and Dawson proposed a criterion (the BRD criterion) for choosing the optimal smoothing parameter when using regularization to solve Fredholm equations. The BRD criterion is tested for its suitability in obtaining optimal SED's. This criterion is found to be too conservative. While using it never introduces nonexistent structure into the SED, significant information is often lost. At present, no simple criterion for choosing the optimal smoothing parameter exists, and a modeling approach is recommended.

  17. CCN1 suppresses pulmonary vascular smooth muscle contraction in response to hypoxia.

    PubMed

    Lee, Seon-Jin; Zhang, Meng; Hu, Kebin; Lin, Ling; Zhang, Duo; Jin, Yang

    2015-12-01

    Pulmonary vasoconstriction and increased vascular resistance are common features in pulmonary hypertension (PH). One of the contributing factors in the development of pulmonary vasoconstriction is increased pulmonary artery smooth muscle cell (PASMC) contraction. Here we report that CCN1, an extracellular matrix molecule, suppressed PASMC contraction in response to hypoxia. CCN1 (Cyr61), discovered in past decade, belongs to the Cyr61-CTGF-Nov (CCN) family. It carries a variety of cellular functions, including angiogenesis and cell adhesion, death, and proliferation. Hypoxia robustly upregulated the expression of CCN1 in the pulmonary vessels and lung parenchyma. Given that CCN1 is a secreted protein and functions in a paracine manner, we examined the potential effects of CCN1 on the adjacent smooth muscle cells. Interestingly, bioactive recombinant CCN1 significantly suppressed hypoxia-induced contraction in human PASMCs in vitro. Consistently, in the in vivo functional studies, administration of bioactive CCN1 protein significantly decreased right ventricular pressure in three different PH animal models. Mechanistically, protein kinase A-pathway inhibitors abolished the effects of CCN1 in suppressing PASMC contraction. Furthermore, CCN1-inhibited smooth muscle contraction was independent of the known vasodilators, such as nitric oxide. Taken together, our studies indicated a novel cellular function of CCN1, potentially regulating the pathogenesis of PH.

  18. Smoothed-particle hydrodynamics and nonequilibrium molecular dynamics

    SciTech Connect

    Hoover, W. G.; Hoover, C. G.

    1993-08-01

    Gingold, Lucy, and Monaghan invented a grid-free version of continuum mechanics ``smoothed-particle hydrodynamics,`` in 1977. It is a likely contributor to ``hybrid`` simulations combining atomistic and continuum simulations. We describe applications of this particle-based continuum technique from the closely-related standpoint of nonequilibrium molecular dynamics. We compare chaotic Lyapunov spectra for atomistic solids and fluids with those which characterize a two-dimensional smoothed-particle fluid system.

  19. Smoothed-particle hydrodynamics and nonequilibrium molecular dynamics

    NASA Astrophysics Data System (ADS)

    Hoover, W. G.; Hoover, C. G.

    1993-08-01

    Gingold, Lucy, and Monaghan invented a grid-free version of continuum mechanics 'smoothed-particle hydrodynamics,' in 1977. It is a likely contributor to 'hybrid' simulations combining atomistic and continuum simulations. We describe applications of this particle-based continuum technique from the closely-related standpoint of nonequilibrium molecular dynamics. We compare chaotic Lyapunov spectra for atomistic solids and fluids with those which characterize a two-dimensional smoothed-particle fluid system.

  20. Airway smooth muscle in exercise-induced bronchospasm: some speculations.

    PubMed

    Middleton, E

    1975-11-01

    Some possible neurophysiological, biochemical, and pharmacological pathways affecting the state of contractility if airway smooth muscle in exercise-induced bronchospasm (EIB) are described. No unifying hypothesis can be set forth at this time. Indeed, it is likely that the heterogeneous nature of EIB is a reflection of the numerous biochemical loci in smooth muscle cells that could be affected by the various metabolic changes accompanying heavy exertion.

  1. Phorbol Ester Effects on Neurotransmission: Interaction with Neurotransmitters and Calcium in Smooth Muscle

    NASA Astrophysics Data System (ADS)

    Baraban, Jay M.; Gould, Robert J.; Peroutka, Stephen J.; Snyder, Solomon H.

    1985-01-01

    Stimulation of the phosphatidylinositol cycle by neurotransmitters generates diacylglycerol, an activator of protein kinase C, which may regulate some forms of neurotransmission. Phorbol esters, potent inflammatory and tumorpromoting compounds, also activate protein kinase C. We demonstrate potent and selective effects of phorbol esters on smooth muscle, indicating a role for protein kinase C in neurotransmission. In rat vas deferens and dog basilar artery, phorbol esters synergize with calcium to mimic the contractile effects of neurotransmitters that act through the phosphatidylinositol cycle. In guinea pig ileum and rat uterus, phorbol esters block contractions produced by these neurotransmitters.

  2. De Novo ACTA2 Mutation Causes a Novel Syndrome of Multisystemic Smooth Muscle Dysfunction

    PubMed Central

    Milewicz, Dianna M.; Østergaard, John R.; Ala-Kokko, Leena M.; Khan, Nadia; Grange, Dorothy K.; Mendoza-Londono, Roberto; Bradley, Timothy J.; Olney, Ann Haskins; Adès, Lesley; Maher, Joseph F.; Guo, Dongchuan; Buja, L. Maximilian; Kim, Dong; Hyland, James C.; Regalado, Ellen S.

    2011-01-01

    Smooth muscle cells (SMCs) contract to perform many physiological functions, including regulation of blood flow and pressure in arteries, contraction of the pupils, peristalsis of the gut and voiding of the bladder. SMC lineage in these organs is characterized by cellular expression of the SMC isoform of α-actin, encoded by the ACTA2 gene. We report here on a unique and de novo mutation in ACTA2, R179H, that causes a syndrome characterized by dysfunction of SMCs throughout the body, leading to aortic and cerebrovascular disease, fixed dilated pupils, hypotonic bladder, malrotation and hypoperistalsis of the gut and pulmonary hypertension. PMID:20734336

  3. Triptolide inhibits TGF-β1-induced cell proliferation in rat airway smooth muscle cells by suppressing Smad signaling

    SciTech Connect

    Chen, Ming; Lv, Zhiqiang; Huang, Linjie; Zhang, Wei; Lin, Xiaoling; Shi, Jianting; Zhang, Wei; Liang, Ruiyun; Jiang, Shanping

    2015-02-15

    Background: We have reported that triptolide can inhibit airway remodeling in a murine model of asthma via TGF-β1/Smad signaling. In the present study, we aimed to investigate the effect of triptolide on airway smooth muscle cells (ASMCs) proliferation and the possible mechanism. Methods: Rat airway smooth muscle cells were cultured and made synchronized, then pretreated with different concentration of triptolide before stimulated by TGF-β1. Cell proliferation was evaluated by MTT assay. Flow cytometry was used to study the influence of triptolide on cell cycle and apoptosis. Signal proteins (Smad2, Smad3 and Smad7) were detected by western blotting analysis. Results: Triptolide significantly inhibited TGF-β1-induced ASMC proliferation (P<0.05). The cell cycle was blocked at G1/S-interphase by triptolide dose dependently. No pro-apoptotic effects were detected under the concentration of triptolide we used. Western blotting analysis showed TGF-β1 induced Smad2 and Smad3 phosphorylation was inhibited by triptolide pretreatment, and the level of Smad7 was increased by triptolide pretreatment. Conclusions: Triptolide may function as an inhibitor of asthma airway remodeling by suppressing ASMCs proliferation via negative regulation of Smad signaling pathway. - Highlights: • In this study, rat airway smooth muscle cells were cultured and made synchronized. • Triptolide inhibited TGF-β1-induced airway smooth muscle cells proliferation. • Triptolide inhibited ASMCs proliferation via negative regulation of Smad signaling pathway.

  4. The evolutionary origin of bilaterian smooth and striated myocytes

    PubMed Central

    Brunet, Thibaut; Fischer, Antje HL; Steinmetz, Patrick RH; Lauri, Antonella; Bertucci, Paola; Arendt, Detlev

    2016-01-01

    The dichotomy between smooth and striated myocytes is fundamental for bilaterian musculature, but its evolutionary origin is unsolved. In particular, interrelationships of visceral smooth muscles remain unclear. Absent in fly and nematode, they have not yet been characterized molecularly outside vertebrates. Here, we characterize expression profile, ultrastructure, contractility and innervation of the musculature in the marine annelid Platynereis dumerilii and identify smooth muscles around the midgut, hindgut and heart that resemble their vertebrate counterparts in molecular fingerprint, contraction speed and nervous control. Our data suggest that both visceral smooth and somatic striated myocytes were present in the protostome-deuterostome ancestor and that smooth myocytes later co-opted the striated contractile module repeatedly – for example, in vertebrate heart evolution. During these smooth-to-striated myocyte conversions, the core regulatory complex of transcription factors conveying myocyte identity remained unchanged, reflecting a general principle in cell type evolution. DOI: http://dx.doi.org/10.7554/eLife.19607.001 PMID:27906129

  5. Stimulation of aortic smooth muscle cell mitogenesis by serotonin

    SciTech Connect

    Nemecek, G.M.; Coughlin, S.R.; Handley, D.A.; Moskowitz, M.A.

    1986-02-01

    Bovine aortic smooth muscle cells in vitro responded to 1 nM to 10 ..mu..M serotonin with increased incorporation of (/sup 3/H)thymidine into DNA. The mitogenic effect of serotonin was half-maximal at 80 nM and maximal above 1 ..mu..M. At a concentration of 1 ..mu..M, serotonin stimulated