scholarly journals A+U-Rich Instability Elements Differentially Activate 5′-3′ and 3′-5′ mRNA Decay

2007 ◽  
Vol 27 (8) ◽  
pp. 2791-2799 ◽  
Author(s):  
Elizabeth L. Murray ◽  
Daniel R. Schoenberg

ABSTRACT The A+U-rich elements (or AREs) are cis-acting sequences that activate rapid mRNA decay, yet the overall polarity of this process is unknown. The current study describes an unbiased approach to this using the Invader RNA assay (Third Wave Technologies, Inc.) to quantify the decay of each of the three exons of human β-globin mRNA without added instability elements or with the AREs from c-fos or granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA in the 3′ untranslated region. Each of these genes under tetracycline operator control was stably transfected into cells, and β-globin mRNA was quantified with exon-specific probes following transcription termination. There was little overall evidence for polarity in stable mRNA decay. Adding the c-fos ARE activated rapid and simultaneous decay from both ends of the mRNA. In contrast, the GM-CSF ARE activated decay primarily from the mRNA 5′ end. These data were supported by reciprocal RNA interference knockdowns, and we present evidence that the 5′-3′ and 3′-5′ decay pathways are functionally linked.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jani Lappalainen ◽  
Nicolas Yeung ◽  
Su D. Nguyen ◽  
Matti Jauhiainen ◽  
Petri T. Kovanen ◽  
...  

AbstractIn atherosclerotic lesions, blood-derived monocytes differentiate into distinct macrophage subpopulations, and further into cholesterol-filled foam cells under a complex milieu of cytokines, which also contains macrophage-colony stimulating factor (M-CSF) and granulocyte–macrophage-colony stimulating factor (GM-CSF). Here we generated human macrophages in the presence of either M-CSF or GM-CSF to obtain M-MØ and GM-MØ, respectively. The macrophages were converted into cholesterol-loaded foam cells by incubating them with acetyl-LDL, and their atheroinflammatory gene expression profiles were then assessed. Compared with GM-MØ, the M-MØ expressed higher levels of CD36, SRA1, and ACAT1, and also exhibited a greater ability to take up acetyl-LDL, esterify cholesterol, and become converted to foam cells. M-MØ foam cells expressed higher levels of ABCA1 and ABCG1, and, correspondingly, exhibited higher rates of cholesterol efflux to apoA-I and HDL2. Cholesterol loading of M-MØ strongly suppressed the high baseline expression of CCL2, whereas in GM-MØ the low baseline expression CCL2 remained unchanged during cholesterol loading. The expression of TNFA, IL1B, and CXCL8 were reduced in LPS-activated macrophage foam cells of either subtype. In summary, cholesterol loading converged the CSF-dependent expression of key genes related to intracellular cholesterol balance and inflammation. These findings suggest that transformation of CSF-polarized macrophages into foam cells may reduce their atheroinflammatory potential in atherogenesis.


2021 ◽  
Vol 14 (5) ◽  
pp. 459
Author(s):  
Mariya Pykhtina ◽  
Svetlana Miroshnichenko ◽  
Vladimir Romanov ◽  
Antonina Grazhdantseva ◽  
Galina Kochneva ◽  
...  

In this study, two strains of the yeast P. pastoris were constructed, one of which produced authentic recombinant human granulocyte-macrophage colony-stimulating factor (ryGM-CSF), and the other was a chimera consisting of ryGM-CSF genetically fused with mature human apolipoprotein A-I (ApoA-I) (ryGM-CSF-ApoA-I). Both forms of the cytokine were secreted into the culture medium. The proteins’ yield during cultivation in flasks was 100 and 60 mg/L for ryGM-CSF and ryGM-CSF-ApoA-I, respectively. Both forms of recombinant GM-CSF stimulated the proliferation of human TF-1 erythroleukemia cells; however, the amount of chimera required was 10-fold that of authentic GM-CSF to induce a similar proliferative effect. RyGM-CSF exhibited a 2-fold proliferative effect on BFU-E (burst-forming units—erythroid) at a concentration 1.7 fold less than non-glycosylated E. coli-derived GM-CSF. The chimera together with authentic ryGM-CSF increased the number of both erythroid precursors and BMC granulocytes after 48 h of incubation of human bone marrow cells (BMCs). In addition, the chimeric form of ryGM-CSF was more effective at increasing the viability of the total amount of BMCs, decreasing apoptosis compared to the authentic form. ryGM-CSF-ApoA-I normalized the proliferation, maturation, and segmentation of neutrophils within the physiological norm, preserving the pool of blast cells under conditions of impaired granulopoiesis. The chimera form of GM-CSF exhibited the properties of a multilinear growth factor, modulating the activity of GM-CSF and, perhaps, it may be more suitable for the normalization of granulopoiesis.


Neonatology ◽  
2021 ◽  
pp. 1-7
Author(s):  
Verena Schulte ◽  
Alexandra Sipol ◽  
Stefan Burdach ◽  
Esther Rieger-Fackeldey

<b><i>Background:</i></b> The granulocyte-macrophage-colony-stimulating factor (GM-CSF) plays an important role in surfactant homeostasis. β<sub>C</sub> is a subunit of the GM-CSF receptor (GM-CSF-R), and its activation mediates surfactant catabolism in the lung. β<sub>IT</sub> is a physiological, truncated isoform of β<sub>C</sub> and is known to act as physiological inhibitor of β<sub>C</sub>. <b><i>Objective:</i></b> The aim of this study was to determine the ratio of β<sub>IT</sub> and β<sub>C</sub> in the peripheral blood of newborns and its association with the degree of respiratory failure at birth. <b><i>Methods:</i></b> We conducted a prospective cohort study in newborns with various degrees of respiratory impairment at birth. Respiratory status was assessed by a score ranging from no respiratory impairment (0) to invasive respiratory support (3). β<sub>IT</sub> and β<sub>C</sub> expression were determined in peripheral blood cells by real-time PCR. β<sub>IT</sub> expression, defined as the ratio of β<sub>IT</sub> and β<sub>C</sub>, was correlated with the respiratory score. <b><i>Results:</i></b> β<sub>IT</sub> expression was found in all 59 recruited newborns with a trend toward higher β<sub>IT</sub> in respiratory ill (score 2, 3) newborns than respiratory healthy newborns ([score 0, 1]; <i>p</i> = 0.066). Seriously ill newborns (score 3) had significantly higher β<sub>IT</sub> than healthy newborns ([score 0], <i>p</i> = 0.010). Healthy preterm infants had significantly higher β<sub>IT</sub> expression than healthy term infants (<i>p</i> = 0.019). <b><i>Conclusions:</i></b> β<sub>IT</sub> is expressed in newborns with higher expression in respiratory ill than respiratory healthy newborns. We hypothesize that β<sub>IT</sub> may have a protective effect in postnatal pulmonary adaptation acting as a physiological inhibitor of β<sub>C</sub> and, therefore, maintaining surfactant in respiratory ill newborns.


Blood ◽  
1992 ◽  
Vol 80 (5) ◽  
pp. 1190-1198 ◽  
Author(s):  
SC Guba ◽  
CI Sartor ◽  
LR Gottschalk ◽  
YH Jing ◽  
T Mulligan ◽  
...  

Abstract Bone marrow (BM) stromal fibroblasts produce hematopoietic growth factors (HGFs) in response to inflammatory mediators such as tumor necrosis factor-alpha or interleukin-1 alpha (IL-1 alpha). In the absence of such inflammatory stimuli, production of HGFs by BM stromal cells has been problematic and controversial. In vivo, however, basal hematopoiesis maintains blood counts within a normal homeostatic range even in the absence of inflammation, and HGFs are required for progenitor cell differentiation in vitro. To better ascertain the contribution of BM stromal fibroblasts to basal hematopoiesis, we therefore studied HGF production in quiescent BM stromal fibroblasts by three sensitive assays: serum-free bioassay, enzyme-linked immunosorbent assay, and reverse transcriptase polymerase chain reaction. Stromal fibroblasts were cultured in the presence or absence of normal human serum to determine if serum factor(s) present in the noninflammatory (basal) state induce secretion of HGFs. Human serum was found to induce or enhance transcription and secretion of granulocyte- macrophage colony-stimulating factor (GM-CSF) and enhance secretion of constitutively expressed IL-6. In contrast, no secretion of either granulocyte-CSF (G-CSF) or IL-3 was found. These data indicate that factors in normal human serum are active in enhancing GM-CSF and IL-6 production by stromal fibroblasts and suggest that these growth factors contribute to the maintainance of normal, basal hematopoiesis in vivo.


Blood ◽  
1989 ◽  
Vol 74 (8) ◽  
pp. 2652-2656 ◽  
Author(s):  
T Gesner ◽  
RA Mufson ◽  
KJ Turner ◽  
SC Clark

Abstract Granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) each bind specifically to a small number of high- affinity receptors present on the surface of the cells of the acute myelogenous leukemia line, KG-1. Through chemical cross-linking of IL-3 and GM-CSF to KG-1 cells, we identified distinct binding proteins for each of these cytokines with approximate molecular masses of 69 and 93 Kd, respectively. Although these two binding proteins are distinct, GM- CSF and IL-3 compete with each other for binding to KG-1 cells. Other cell lines, which express receptors for either factor but not for both do not display this cross-competition for binding with IL-3 and GM-CSF. These findings imply that distinct IL-3 and GM-CSF binding proteins are expressed on the cell surface and that an association exists between these proteins on KG-1 cells.


Blood ◽  
1996 ◽  
Vol 88 (4) ◽  
pp. 1206-1214 ◽  
Author(s):  
RL Rosen ◽  
KD Winestock ◽  
G Chen ◽  
X Liu ◽  
L Hennighausen ◽  
...  

Granulocyte-macrophage colony-stimulating factor (GM-CSF) induces immediate effects in monocytes by activation of the Janus kinase (JAK2) and STAT transcription factor (STAT5) pathway. Recent studies have identified homologues of STAT5, STAT5A, and STAT5B, as well as lower molecular weight variants of STAT5. To define the activation of the STAT5 homologues and lower molecular weight variant in human monocytes and monocytes differentiated into macrophages by culture in macrophage- CSF (M-CSF), we measured the GM-CSF induced tyrosine phosphorylation of STAT5A, STAT5B, and any lower molecular weight STAT5 isoforms. Freshly isolated monocytes expressed 94-kD STAT5A, 92-kD STAT5B, and an 80-kD STAT5A molecule. Whereas 94-kD STAT5A was clearly tyrosine phosphorylated and bound to the enhancer element, the gamma response region (GRR), of the Fc gamma RI gene, substantially less tyrosine phosphorylated STAT5B bound to the immobilized GRR element. Macrophages lost their ability to express the 80-kD STAT5A protein, but retained their ability to activate STAT5A. STAT5A-STAT5A homodimers and STAT5A- STAT5B heterodimers formed in response to GM-CSF. Therefore, activation of STAT5A predominates compared to STAT5B when assayed by direct immunoprecipitation and by evaluation of bound STATs to immobilized GRR. Selective activation of STAT5 homologues in addition to generation of lower molecular isoforms may provide specificity and control to genes expressed in response to cytokines such as GM-CSF.


2008 ◽  
Vol 68 (5) ◽  
pp. 721-728 ◽  
Author(s):  
C Plater-Zyberk ◽  
L A B Joosten ◽  
M M A Helsen ◽  
M I Koenders ◽  
P A Baeuerle ◽  
...  

Objective:A pathogenic role for granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin (IL)17 in rheumatoid arthritis (RA) has been suggested. In previously published work, the therapeutic potentials of GM-CSF and IL17 blockade in arthritis have been described. In the present study, the simultaneous blockade of both pathways in a mouse model for chronic arthritis was investigated to identify whether this double blockade provides a superior therapeutic efficacy.Methods:A chronic relapsing arthritis was induced in C57Bl/6 wild type (WT) and C57Bl/6 genetically deficient for IL17 receptor (IL17R knockout (KO)) mice by intra-articular injection of Streptococcal cell wall (SCW) fragments into knees on days 0, 7, 14 and 21. Treatments (intraperitoneal) were given weekly starting on day 14. Animals were analysed for inflammation, joint damage and a range of inflammatory mediators.Results:Joint swelling and cartilage damage were significantly reduced in the IL17R KO mice and in WT mice receiving anti-GM-CSF neutralising mAb 22E9 compared to isotype control antibodies. The therapeutic effect was significantly more pronounced in mice where IL17 and GM-CSF pathways were inhibited (eg, IL17R KO mice treated with 22E9 mAb). Tumour necrosis factor (TNF)α blockade had essentially no effect.Conclusion:Our data further support the therapeutic potentials of GM-CSF and IL17 blockade in a RA model that is no longer responsive to an established TNFα antagonist, moreover, our results suggest that concomitant inhibition of both pathways may provide the basis for a highly effective treatment of chronic RA in patients that are resistant to treatment by TNFα inhibitors.


Sign in / Sign up

Export Citation Format

Share Document