scholarly journals A rapid method for measuring the steady state levels of mitochondrial RNA in whole mitochondria

1992 ◽  
Vol 20 (1) ◽  
pp. 142-142 ◽  
Author(s):  
M. Guérin ◽  
P. Pélissier
Keyword(s):  
Steady State ◽  
Rapid Method ◽  
Mitochondrial Rna ◽  
Steady State Levels

scholarly journals UTP-Dependent and -Independent Pathways of mRNA Turnover in Trypanosoma brucei Mitochondria

2000 ◽  
Vol 20 (7) ◽  
pp. 2308-2316 ◽  
Author(s):  
Kevin T. Militello ◽  
Laurie K. Read
Keyword(s):  
Steady State ◽  
Trypanosoma Brucei ◽  
Mitochondrial Gene ◽  
Rna Stability ◽  
Degradation Pathway ◽  
Mitochondrial Rna ◽  
In Organello ◽  
Steady State Levels ◽  
The Stability ◽  
Mrna Polyadenylation

ABSTRACT Although primary transcripts are polycistronic in the mitochondria of Trypanosoma brucei, steady-state levels of mature, monocistronic RNAs change throughout the parasitic life cycle. This indicates that steady-state RNA abundance is controlled by posttranscriptional mechanisms involving differential RNA stability. In this study, in organello pulse-chase labeling experiments were used to analyze the stability of different T. brucei mitochondrial RNA populations. In this system, total RNA and rRNA are stable for many hours. In contrast, mRNAs can be degraded by two biochemically distinct turnover pathways. The first pathway results in the rapid degradation of mRNA (half-life [t 1/2] of 11 to 18 min) and is dependent upon the presence of an mRNA poly(A) tail. Remarkably, this pathway also requires the addition of UTP and therefore is termed UTP dependent. The second pathway results in slow turnover of mitochondrial mRNA (t 1/2 of ∼3 h) and is not dependent upon the presence of an mRNA poly(A) tail or the addition of exogenous UTP. In summary, these results demonstrate the presence of a novel, UTP-dependent degradation pathway for T. bruceimitochondrial mRNAs and reveal an unprecedented role for both UTP and mRNA polyadenylation in T. brucei mitochondrial gene expression.

Reduced steady-state levels of mitochondrial RNA and increased mitochondrial DNA amount in human brain with aging

1997 ◽  
Vol 52 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Antoni Barrientos ◽  
Jordi Casademont ◽  
Francesc Cardellach ◽  
Xavier Estivill ◽  
Alvaro Urbano-Marquez ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Steady State ◽  
Human Brain ◽  
Mitochondrial Rna ◽  
Dna Amount ◽  
Steady State Levels

scholarly journals The critical role of T cells in glucocorticoid-induced osteoporosis

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Lin Song ◽  
Lijuan Cao ◽  
Rui Liu ◽  
Hui Ma ◽  
Yanan Li ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Steady State ◽  
Side Effects ◽  
Critical Role ◽  
Wild Type ◽  
Receptor Activator ◽  
Steady State Levels ◽  
Induced Apoptosis

AbstractGlucocorticoids (GC) are widely used clinically, despite the presence of significant side effects, including glucocorticoid-induced osteoporosis (GIOP). While GC are believed to act directly on osteoblasts and osteoclasts to promote osteoporosis, the detailed underlying molecular mechanism of GC-induced osteoporosis is still not fully elucidated. Here, we show that lymphocytes play a pivotal role in regulating GC-induced osteoporosis. We show that GIOP could not be induced in SCID mice that lack T cells, but it could be re-established by adoptive transfer of splenic T cells from wild-type mice. As expected, T cells in the periphery are greatly reduced by GC; instead, they accumulate in the bone marrow where they are protected from GC-induced apoptosis. These bone marrow T cells in GC-treated mice express high steady-state levels of NF-κB receptor activator ligand (RANKL), which promotes the formation and maturation of osteoclasts and induces osteoporosis. Taken together, these findings reveal a critical role for T cells in GIOP.

The Olympic Games as a News Shock

2017 ◽  
Vol 19 (6) ◽  
pp. 884-906 ◽  
Author(s):  
Viktoria C. E. Langer ◽  
Wolfgang Maennig ◽  
Felix Richter
Keyword(s):  
Steady State ◽  
Olympic Games ◽  
Structural Models ◽  
Adjustment Process ◽  
Dynamic Adjustment ◽  
Economic Variables ◽  
Long Run ◽  
News Shock ◽  
Steady State Levels ◽  
The Olympic Games

The awarding of the Olympic Games to a certain city or the announcement of a city’s Olympic bid may be considered as a news shock that affects agents’ market expectations. A news shock implies potential impacts on the dynamic adjustment process that change not only the volatility but also the long-run steady-state levels of endogenous economic variables. In this study, we contribute to and extend previous researchers’ attempts to empirically test for the Olympic Games as a news shock by implementing full structural models and by matching Olympic hosts and bidders to structurally similar countries.

Quantitative assessment of ground squirrel mRNA levels in multiple stages of hibernation

2002 ◽  
Vol 10 (2) ◽  
pp. 93-102 ◽  
Author(s):  
L. Elaine Epperson ◽  
Sandra L. Martin
Keyword(s):  
Steady State ◽  
Core Body Temperature ◽  
Ground Squirrels ◽  
Apolipoprotein A1 ◽  
Mrna Levels ◽  
Cdna Subtraction ◽  
Global Issues ◽  
Α2 Macroglobulin ◽  
Steady State Levels ◽  
Molecular Components

Hibernators in torpor dramatically reduce their metabolic, respiratory, and heart rates and core body temperature. These extreme physiological conditions are frequently and rapidly reversed during the winter hibernation season via endogenous mechanisms. This phenotype must derive from regulated expression of the hibernator’s genome; to identify its molecular components, a cDNA subtraction was used to enrich for seasonally upregulated mRNAs in liver of golden-mantled ground squirrels. The relative steady-state levels for seven mRNAs identified by this screen, plus five others, were measured and analyzed for seasonal and stage-specific differences using kinetic RT-PCR. Four mRNAs show seasonal upregulation in which all five winter stages differ significantly from and are higher than summer (α2-macroglobulin, apolipoprotein A1, cathepsin H, and thyroxine-binding globulin). One of these mRNAs, α2-macroglobulin, varies during the winter stages with significantly lower levels at late torpor. None of the 12 mRNAs increased during torpor. The implications for these newly recognized upregulated mRNAs for hibernation as well as more global issues of maintaining steady-state levels of mRNA during torpor are discussed.

scholarly journals Accumulation of Non-steroidal Anti-inflammatory Drugs by Gingival Fibroblasts

2006 ◽  
Vol 85 (5) ◽  
pp. 452-456 ◽  
Author(s):  
M.M. Zavarella ◽  
O. Gbemi ◽  
J.D. Walters
Keyword(s):  
Steady State ◽  
Connective Tissue ◽  
Inflammatory Mediator ◽  
Dependent Manner ◽  
Gingival Fibroblasts ◽  
Temperature Dependent ◽  
Tnf Α ◽  
Steady State Levels ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

Non-steroidal anti-inflammatory drugs (NSAIDs) are used to manage pain and inflammatory disorders. We hypothesized that gingival fibroblasts actively accumulate NSAIDs and enhance their levels in gingival connective tissue. Using fluorescence to monitor NSAID transport, we demonstrated that cultured gingival fibroblasts transport naproxen in a saturable, temperature-dependent manner with a Km of 127 μg/mL and a Vmax of 1.42 ng/min/μg protein. At steady state, the intracellular/extracellular concentration ratio was 1.9 for naproxen and 7.2 for ibuprofen. Naproxen transport was most efficient at neutral pH and was significantly enhanced upon cell treatment with TNF-α. In humans, systemically administered naproxen attained steady-state levels of 61.9 μg/mL in blood and 9.4 μg/g in healthy gingival connective tissue, while ibuprofen attained levels of 2.3 μg/mL and 1.5 μg/g, respectively. Thus, gingival fibroblasts possess transporters for NSAIDs that are up-regulated by an inflammatory mediator, but there is no evidence that they contribute to elevated NSAID levels in healthy gingiva.

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