Phorbol 12-myristate 13-acetate alters SR Ca(2+)-ATPase gene expression in cultured neonatal rat heart cells

1996 ◽  
Vol 271 (3) ◽  
pp. H1031-H1039 ◽  
Author(s):  
M. Qi ◽  
J. W. Bassani ◽  
D. M. Bers ◽  
A. M. Samarel
Keyword(s):  
Gene Expression ◽  
Sarcoplasmic Reticulum ◽  
Mrna Stability ◽  
Primary Cultures ◽  
Neonatal Rat ◽  
Response To Treatment ◽  
Similar Degree ◽  
Heart Cells ◽  
Mrna Levels ◽  
Atpase Gene

Primary cultures of neonatal rat ventricular myocytes were used to examine how the cardiac myocyte cytoplasmic Ca2+ ([Ca2+]i) transient and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2) gene expression change in response to treatment with the protein kinase C activator phorbol 12-myristate 13-acetate (PMA). Exposure of neonatal myocytes to PMA (200 nM, 48-72 h) produced myocyte growth and a 70% prolongation of the half-time for [Ca2+]i decline induced by potassium depolarization in the absence of extracellular Na+ (in which the sarcoplasmic reticulum Ca2+ pump is the main mechanism responsible for [Ca2+]i decline). The reduced rate of [Ca2+]i transient decline corresponded to a 53% reduction in SERCA2 protein levels and a 43% reduction in SERCA2 mRNA levels as compared with control myocytes. Exposure to PMA for as little as 30 min or for as long as 48 h produced a similar degree of SERCA2 mRNA downregulation over time. PMA-induced downregulation of SERCA2 mRNA levels was blocked by either 10 nM staurosporine or 4 microM chelerythrine, whereas treatment with either agent alone increased SERCA2 mRNA levels as compared with control cells. Actinomycin D mRNA stability assays revealed that PMA treatment appeared to markedly destabilize the relatively long-lived SERCA2 mRNA transcript. Taken together, these results indicate that downregulation of SERCA2 gene by PMA in cultured neonatal myocytes occurs at least in part by alterations in mRNA stability and results in functional alterations in [Ca2+]i decline that are similar to that observed in the hypertrophied and failing adult myocardium.

Thyroid hormone-induced stimulation of the sarcoplasmic reticulum Ca2+ ATPase gene is inhibited by LIF and IL-6

2000 ◽  
Vol 278 (4) ◽  
pp. E738-E743 ◽  
Author(s):  
Bernd Gloss ◽  
Sonia Villegas ◽  
Francisco J. Villarreal ◽  
Anselmo Moriscot ◽  
Wolfgang H. Dillmann
Keyword(s):  
Gene Expression ◽  
Thyroid Hormone ◽  
Sarcoplasmic Reticulum ◽  
Cardiac Myocytes ◽  
Transcriptional Activity ◽  
Neonatal Rat ◽  
Mrna Levels ◽  
Cytokine Inhibition ◽  
Atpase Gene ◽  
Promoter Construct

We investigated the effects of the leukemia inhibitory factor (LIF) and interleukin-6 (IL-6) on 3,3′, 5-triiodo-l-thyronine, or thyroid hormone (T3)-stimulated sarcoplasmic reticulum Ca2+ATPase (SERCA2) gene expression on cultured neonatal rat cardiac myocytes. A reduction of T3 induced increases in SERCA2 mRNA levels after co-treatment with LIF or IL-6. To investigate for the molecular mechanism(s) responsible for the blunted gene expression, a 3.2-kb SERCA2 promoter construct containing a reporter gene was transfected into cardiac myocytes. T3 treatment stimulated transcriptional activity twofold, whereas co-treatment with T3 and either of the cytokines caused an inhibition of T3-induced SERCA2 transcriptional activity. A T3-responsive 0.6-kb SERCA2 construct also showed a similar inhibition by cytokines. Cytokine inhibition of SERCA2 transcriptional activity was also evident when a 0.6-kb SERCA2 mutant, T3-unresponsive promoter construct was used. Treatment with T3 and cytokines showed a significant decrease in transcription when a reporter construct was used that was comprised of direct repeats of SERCA2 thyroid response element I. These data provide evidence for cytokine-mediated inhibitory effects on the SERCA2 promoter that may be mediated by interfering with T3action.

Myosin heavy chain gene expression in neonatal rat heart cells: effects of [Ca2+]i and contractile activity

1997 ◽  
Vol 273 (2) ◽  
pp. C394-C403 ◽  
Author(s):  
M. Qi ◽  
J. L. Puglisi ◽  
K. L. Byron ◽  
K. Ojamaa ◽  
I. Klein ◽  
...  
Keyword(s):  
Gene Expression ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Promoter Activity ◽  
Contractile Activity ◽  
Neonatal Rat ◽  
Luciferase Expression ◽  
Heart Cells ◽  
Mrna Levels ◽  
Mechanical Signals

To determine if mechanical signals or alterations in intracellular Ca2+ concentration ([Ca2+]i) affect myosin heavy chain (MHC) gene expression in spontaneously beating, neonatal rat ventricular myocytes, contractile activity was inhibited with verapamil, KCl, or 2,3-butanedione monoxime (BDM), and their acute and chronic effects on myocyte shortening, [Ca2+]i, and MHC gene expression were examined. Despite their differing effects on [Ca2+]i, verapamil, KCl, and BDM all inhibited contractile activity and markedly downregulated beta-MHC mRNA levels to 24 +/- 5, 21 +/- 7, and 6 +/- 2% of contracting cells, respectively. In contrast, these inhibitors of contraction upregulated alpha-MHC mRNA levels to 163 +/- 19, 156 +/- 7, and 198 +/- 20% of contracting cells, respectively. Transient transfection with a rat beta-MHC promoter-luciferase expression plasmid demonstrated that all inhibitors of contraction significantly decreased beta-MHC promoter activity. Paradoxically, contractile arrest also inhibited alpha-MHC promoter activity, suggesting that increased alpha-MHC mRNA levels resulted from posttranscriptional mechanisms. Actinomycin D mRNA stability assays indicated that alpha-MHC mRNA half-life was prolonged in noncontracting cells (33 h) compared with contracting myocytes (14 h). Contraction-dependent alterations in MHC gene expression were not dependent on release of angiotensin II or other growth factors into the culture medium. Thus intrinsic mechanical signals rather than alterations in [Ca2+]i regulate alpha-MHC and beta-MHC gene expression by both transcriptional and posttranscriptional mechanisms.

Nitric oxide increases IL-8 gene transcription and mRNA stability to enhance IL-8 gene expression in lung epithelial cells

2004 ◽  
Vol 287 (4) ◽  
pp. L764-L773 ◽  
Author(s):  
Loretta Sparkman ◽  
Vijayakumar Boggaram
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Gene Transcription ◽  
Mrna Stability ◽  
Inflammatory Responses ◽  
Lung Epithelial Cells ◽  
Mrna Levels ◽  
Lung Epithelial

Interleukin (IL)-8, a C-X-C chemokine, is a potent chemoattractant and an activator for neutrophils, T cells, and other immune cells. The airway and respiratory epithelia play important roles in the initiation and modulation of inflammatory responses via production of cytokines and surfactant. The association between elevated levels of nitric oxide (NO) and IL-8 in acute lung injury associated with sepsis, acute respiratory distress syndrome, respiratory syncytial virus infection in infants, and other inflammatory diseases suggested that NO may play important roles in the control of IL-8 gene expression in the lung. We investigated the role of NO in the control of IL-8 gene expression in H441 lung epithelial cells. We found that a variety of NO donors significantly induced IL-8 mRNA levels, and the increase in IL-8 mRNA was associated with an increase in IL-8 protein. NO induction of IL-8 mRNA was due to increases in IL-8 gene transcription and mRNA stability. NO induction of IL-8 mRNA levels was not inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one and KT-5823, inhibitors of soluble guanylate cyclase and protein kinase G, respectively, and 8-bromo-cGMP did not increase IL-8 mRNA levels. This indicated that NO induces IL-8 mRNA levels independently of changes in the intracellular cGMP levels. NO induction of IL-8 mRNA was significantly reduced by inhibitors of extracellular regulated kinase and protein kinase C. IL-8 induction by NO was also reduced by hydroxyl radical scavengers such as dimethyl sulfoxide and dimethylthiourea, indicating the involvement of hydroxyl radicals in the induction process. NO induction of IL-8 gene expression could be a significant contributing factor in the initiation and induction of inflammatory response in the respiratory epithelium.

Abstract 2423: B-type Natriuretic Peptide Upregulates Erythropoietin Receptor Gene Expression via Protein Kinase G in Heart Failure

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Yoshiaki Ohyama ◽  
Toru Tanaka ◽  
Takehisa Shimizu ◽  
Hiroshi Doi ◽  
Norimichi Koitabashi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Protein Kinase ◽  
Cardiac Myocytes ◽  
Natriuretic Peptide ◽  
Neonatal Rat ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Failing Heart ◽  
Epor Expression

Backgroud: Recent studies demonstrated non-hematopoietical effects of Erythropoietin (Epo) and its receptor (EpoR) in a variety of tissues including cardiovascular system. Epo treatment improves cardiac function in patients with heart failure and reduces infarct size after ischemia/reperfusion injury in the heart. However, little attention has been paid for the endogenous regulatory mechanisms regulating EpoR expression. In this study, we hypothesize that B-type natriuretic peptide upregulates EpoR gene expression in failing heart. Methods and Results: Wister rats underwent transverse aortic constriction surgery to induce hypertrophy. RT-PCR analyses of those rats showed that EpoR mRNA levels were increased in the left ventricle and positively correlated with the levels of BNP mRNA (n=10, r=0.67, p<0.05). Next we examined the expression of EpoR in human failing heart by using autopsy specimens and found that EpoR mRNA levels were significantly elevated in patients with dilated cardiomyopathy compared with those in normal heart. Immunohistochemistry of endomyocardial biopsy specimens of failing heart (n=54) showed that EpoR mRNA levels were correlated with severity of cardiac dysfunction estimated by diameter of cardiac chambers, pathomorphology, serum BNP concentration and functional class of New York Heart Association. Interestingly, stimulation of cultured neonatal rat cardiac myocytes with BNP, but not with hypertrophic reagents including endothelin I, angiotensin II and norepinephrine, significantly increased the EpoR mRNA levels in a time-dependent manner. Overexpression of cGMP-dependent protein kinase (PKG) increased EpoR transcript in cultured cardiac myocytes. BNP-induced EpoR expression was abrogated in the presence of KT5823, a specific inhibitor for PKG. Conclusion: These results suggest a role for BNP in mediating an induction of EpoR expression in failing myocardium and indicate that the cardiac EpoR gene is a target of cGMP/PKG signaling.

scholarly journals Differential regulation of mRNA fate by the human Ccr4-Not complex is driven by coding sequence composition and mRNA localization

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sarah L. Gillen ◽  
Chiara Giacomelli ◽  
Kelly Hodge ◽  
Sara Zanivan ◽  
Martin Bushell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Mrna Stability ◽  
Mrna Localization ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Translational Efficiency ◽  
Mrna Levels ◽  
Control Of Gene Expression ◽  
Mrna Fate

Abstract Background Regulation of protein output at the level of translation allows for a rapid adaptation to dynamic changes to the cell’s requirements. This precise control of gene expression is achieved by complex and interlinked biochemical processes that modulate both the protein synthesis rate and stability of each individual mRNA. A major factor coordinating this regulation is the Ccr4-Not complex. Despite playing a role in most stages of the mRNA life cycle, no attempt has been made to take a global integrated view of how the Ccr4-Not complex affects gene expression. Results This study has taken a comprehensive approach to investigate post-transcriptional regulation mediated by the Ccr4-Not complex assessing steady-state mRNA levels, ribosome position, mRNA stability, and protein production transcriptome-wide. Depletion of the scaffold protein CNOT1 results in a global upregulation of mRNA stability and the preferential stabilization of mRNAs enriched for G/C-ending codons. We also uncover that mRNAs targeted to the ER for their translation have reduced translational efficiency when CNOT1 is depleted, specifically downstream of the signal sequence cleavage site. In contrast, translationally upregulated mRNAs are normally localized in p-bodies, contain disorder-promoting amino acids, and encode nuclear localized proteins. Finally, we identify ribosome pause sites that are resolved or induced by the depletion of CNOT1. Conclusions We define the key mRNA features that determine how the human Ccr4-Not complex differentially regulates mRNA fate and protein synthesis through a mechanism linked to codon composition, amino acid usage, and mRNA localization.

Skeletal Muscle Sarcoplasmic Reticulum Ca 2+ -ATPase Gene Expression in Congestive Heart Failure

1997 ◽  
Vol 81 (5) ◽  
pp. 703-710 ◽  
Author(s):  
David G. Peters ◽  
Heather L. Mitchell ◽  
Sylvia A. McCune ◽  
Sonhee Park ◽  
Jay H. Williams ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Skeletal Muscle ◽  
Congestive Heart Failure ◽  
Sarcoplasmic Reticulum ◽  
Atpase Gene

Dexamethasone stimulates transcription of the Na+-K+-ATPase β1gene in adult rat lung epithelial cells

2003 ◽  
Vol 285 (3) ◽  
pp. L593-L601 ◽  
Author(s):  
Hong Hao ◽  
Christine H. Wendt ◽  
Gurpreet Sandhu ◽  
David H. Ingbar
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Regulatory Elements ◽  
Lung Epithelial Cells ◽  
Mrna Levels ◽  
Rat Lung ◽  
Alveolar Epithelial ◽  
Adult Rat ◽  
Atpase Gene ◽  
Lung Epithelial

Na+-K+-ATPase plays an essential role in active alveolar epithelial fluid resorption. In fetal and adult alveolar epithelial cells, glucocorticoids (GC) increase Na+-K+-ATPase activity and mRNA levels. We sought to define the mechanism of Na+-K+-ATPase gene upregulation by GC. In a rat alveolar epithelial cell line (RLE), dexamethasone (Dex) increased β1-subunit Na+-K+-ATPase mRNA expression two- to threefold within 3 h after exposure to the GC. The increased gene expression was due to increased transcription as demonstrated by nuclear run-on assays, whereas mRNA stability remained unchanged. Transient transfection of 5′ deletion mutants of a β1promoter-reporter construct demonstrated a 1.5- to 2.2-fold increase in promoter activity by Dex. All of the 5′ deletion constructs contained partial or palindromic GC regulatory elements (GRE) and responded to GC. The increased expression of promoter reporter was inhibited by RU-486, a GC receptor (GR) antagonist, suggesting the involvement of GR. The palindromic GRE at -631 demonstrated Dex induction in a heterologous promoter construct. Gel mobility shift assays using RLE nuclear extracts demonstrated specific binding to this site and the presence of GR. We conclude that GC directly stimulate transcription of Na+-K+-ATPase β1gene expression in adult rat lung epithelial cells through a GR-dependent mechanism that can act at multiple sites.

Acute hypoxia stimulates renin secretion and renin gene expression in vivo but not in vitro

1997 ◽  
Vol 272 (4) ◽  
pp. R1105-R1111 ◽  
Author(s):  
T. Ritthaler ◽  
K. Schricker ◽  
F. Kees ◽  
B. Kramer ◽  
A. Kurtz
Keyword(s):  
Gene Expression ◽  
Acute Hypoxia ◽  
Primary Cultures ◽  
Renin Secretion ◽  
Plasma Norepinephrine ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Renin Gene ◽  
Renin Mrna

This study aimed at examining the influence of acute hypoxia on renin secretion and renin gene expression in the kidney. To this end, male Sprague-Dawley rats were exposed to severe hypoxic stress (8% O2) or to carbon monoxide (0.1% CO) for 6 h, and plasma renin activity (PRA) and renal renin mRNA levels were determined. PRA values increased from 3 to 13 and 10 ng angiotensin I x h(-1) x ml(-1), and renin mRNA levels increased by 120 and 100% during hypoxia and CO, respectively. Lowering the PO2 from 150 to 20 or 7 mmHg in the gas atmosphere of primary cultures of renal juxtaglomerular cells had no influence on renin secretion and renin gene expression after 6 and 20 h. Our findings thus suggest that both arterial and venous hypoxia can be powerful stimulators of renin secretion and renin gene expression in vivo. Because renal denervation did not prevent stimulation of the renin system by hypoxia, the effect could be indirectly mediated via the baroreceptor-macula densa mechanism. Another potential mediator of the effect could be circulating catecholamines, since we found that plasma norepinephrine increased from 0.7 to 1.5 and 2.4 ng/ml and plasma epinephrine increased from 0.3 to 1.4 and 2.7 ng/ml during hypoxia and CO inhalation, respectively.

Aldosterone enhances renin gene expression in juxtaglomerular cells

2004 ◽  
Vol 286 (2) ◽  
pp. F349-F355 ◽  
Author(s):  
Jürgen Klar ◽  
Helga Vitzthum ◽  
Armin Kurtz
Keyword(s):  
Gene Expression ◽  
Primary Cultures ◽  
Cellular Level ◽  
Juxtaglomerular Cells ◽  
Mrna Levels ◽  
Renin Synthesis ◽  
Corticosteroid Hormones ◽  
Renin Gene ◽  
Renin Mrna ◽  
Mrna Half Life

The secretion and synthesis of renin as the key regulator of the renin-angiotensin-aldosterone system are directly controlled by ANG II in the sense of a negative feedback. Because we found that renal afferent arterioles including the juxtaglomerular portion express the mineralocorticoid receptor, we aimed to characterize a possible direct effect of aldosterone on renin synthesis and renin secretion at the level of renal juxtaglomerular cells. Aldosterone (100 nM) clearly enhanced renin mRNA levels in primary cultures of mouse juxtaglomerular cells prestimulated with isoproterenol (100 nM) but had no effect on the exocytosis of stored renin. Similarly, in the mouse juxtaglomerular cell line As4.1, aldosterone time and concentration dependently increased renin mRNA abundance and prorenin secretion up to 2.5-fold. Moreover, aldosterone potentiated cAMP-induced renin gene expression in As4.1 cells. The effect of aldosterone was inhibited by spironolactone and was mimicked by corticosteroid hormones but not by sex steroids. Aldosterone had no influence on basal renin promoter activity but increased the renin mRNA half-life about threefold. In summary, these data suggest that aldosterone exerts a direct positive effect on renin gene expression at the cellular level probably by stabilizing renin mRNA.

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