Posts Tagged ‘Berlin’

What about Circular RNAs?

Reporter: Larry H Bernstein, MD, FCAP

Circular RNAs throw genetics for a loop

RNA ‘sponges’ mop up sequences that curb gene expression.
Heidi Ledford       27 Feb 2013

At least some of the loops, described in two papers published this week by Nature1, 2,

  • act as molecular sponges’,
    • binding to and
    • blocking tiny gene modulators called microRNAs.

The researchers suspect that the circular RNAs have many other functions. The molecules comprise “a hidden, parallel universe” of unexplored RNAs, says Nikolaus Rajewsky, the lead author of one of the studies and a systems biologist at the Max Delbrück Center for Molecular Medicine in Berlin. The discovery is yet another a reminder that

  • RNA is much more than a mundane messenger ­between DNA and the proteins it encodes.
1. Memczak , S. et al. Nature 2013         http://dx.doi.org/10.1038/nature11928/
2. Hansen, T. B. et al. Nature 2013        http://dx.doi.org/10.1038/nature11993/
3. Salzman, J., Gawad, C., Wang, P. L., Lacayo, N. & Brown, P. O. 2012        http://www.PLoSONE.org/7/30733
Consensus secondary structure of yjdF RNAs. Th...

Consensus secondary structure of yjdF RNAs. This figure is adapted from a previous publication. (Photo credit: Wikipedia)


RNA (Photo credit: AJC1)

By Richard Wheeler (Zephyris) 2007. Lambda rep...

By Richard Wheeler (Zephyris) 2007. Lambda repressor protein bound to a lambda operator DNA sequence. From . (Photo credit: Wikipedia)

Consensus secondary structure of mini-ykkC RNA...

Consensus secondary structure of mini-ykkC RNAs. Layout is similar to that used in a previously published drawing. (Photo credit: Wikipedia)

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Reported by: Dr. Venkat S. Karra, Ph.D.

A new proof-of-concept study shows that plasma concentrations of precursor fragments of the neuropeptide enkephalin (proenkephalin A, or PENK-A) are elevated in patients with acute stroke compared with those with TIA and nonischemic events.

Researchers are making efforts to investigate neuropeptides in patients presenting with symptoms of acute cerebrovascular disease.

Although the mature neuropeptides are degraded within minutes, their precursor fragments are much more stable and represent neuropeptide synthesis in stoichiometric relations. “They are therefore well suited as biomarkers and may be suitable for measurement in clinical settings,” said Dr. Doehner.

The precursor neuropeptides proenkephalin A (PENK-A) and protachykinin (PTA) are markers of blood-brain barrier integrity and have been recently discussed in vascular dementia and neuroinflammatory disorders.

{Ernst  A., Kohrle  J., Bergmann  A.;  Proenkephalin A 119—159, a stable proenkephalin. A precursor fragment identified in human circulation, Peptides 27 2006 1835-1840
Ernst  A., Suhr  J., Kohrle  J., Bergmann  A.;  Detection of stable N-terminal protachykinin A immunoreactivity in human plasma and cerebrospinal fluid, Peptides 29 2008 1201-1206}

Researchers are making efforts to use these precursor fragments as markers to distinguish an ischemic stroke from a transient ischemic attack (TIA) or an intracerebral hemorrhage.

The authors strongly hope that it may help to advance the use of biomarkers in the clinical evaluation of stroke patients.

Despite the limitations, elevated PENK-A levels correlated with stroke severity and with brain lesion size, and they predicted mortality and more functional disability.

“There is clearly an unmet need to establish biomarker-guided prognostic and functional evaluations for patients with stroke, said the lead author Wolfram Doehner, MD, PhD, from the Center for Stroke Research, in Berlin, Germany

The new report was published in Journal of the American College of Cardiology.







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