Wednesday June 19, 2019

Indian Researchers discover Fibrinogen, a Blood Protein that opens up new horizons in designing Drugs for Alzheimer’s Disease

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A researcher holds a human brain. VOA

Kolkata, Dec 9, 2016: Opening up new horizons in designing drugs for Alzheimer’s disease, Indian researchers have discovered that fibrinogen, a protein that is essential to stop bleeding by helping form blood clot, may arrest the damage caused to nerve cells in the devastating neuro-degenerative disorder.

Alzheimer’s disease (AD) is characterised by extensive loss of neurons and deposition of amyloid beta peptide in the form of plaques. The amyloid plaques that form between the brain’s neurons as it ages are toxic and hence cause the cognitive losses associated with Alzheimer’s. “We have, for the first time, demonstrated that the cytotoxic effects of amyloid beta can be prevented by fibrinogen in a dose-dependent manner.

Fibrinogen acts as a shield or antidote against its toxicity,” lead scientist of the study Debabrata Dash from Banaras Hindu University (BHU), told IANS on Thursday. Dash said the toxic effects of amyloid beta on blood platelets as well as on neuronal cells can be significantly reduced by pre-treatment with fibrinogen. “As fibrinogen is already known to bind amyloid beta, it can capture or sequester amyloid beta and prevent the latter from interacting with neuronal cells or platelets,” he said. There is a catch.

Fibrinogen does not cross blood-brain barrier (BBB) so this rules out the possibility of the protein gaining entry into brain and capturing the rogue amyloid beta peptides. “But peptides or small molecules resembling parts of fibrinogen can be designed which can cross blood-brain barrier to sequester amyloid beta in brain and can act as a novel therapeutic strategy against Alzheimer’s,” Dash explained, adding this is the scientists’ future plan.

The study was published in the journal Molecular Medicine. Apart from BHU, the study involved researchers from Indian Institute of Science Education and Research, Kolkata and Indian Institute of Toxicological Research Centre in Lucknow.

The idea posited in the study could also work in favour of advanced diagnostics. “The peptides that we intend to use for therapeutics can be conjugated with MRI contrast agents. It might be possible to detect or image amyloid plaques within the brain of AD patients non-invasively employing magnetic resonance imaging using these conjugated peptides capable of binding to amyloid plaques after crossing blood brain barrier,” he added. (IANS)

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Researchers Develop New Test to Detect Alzheimer’s Disease Even Before the Symptoms Occur

Now, new clinical studies with test participants in very early stages of the disease can be launched

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In Alzheimer's disease, patients start losing memory. Pixabay

Researchers have developed a new test that could help doctors detect Alzheimer’s disease eight years before the first symptoms occur.

Using current techniques, Alzheimer’s disease, the most frequent cause of dementia, can only be detected once the typical plaques have formed in the brain.

At this point, therapy seems no longer possible. However, the first changes caused by Alzheimer’s take place on the protein level up to 20 years sooner.

“Once amyloid plaques have formed, it seems that the disease can no longer be treated,” said study co-author Andreas Nabers from Ruhr-University Bochum in Germany.

In Alzheimer’s patients, the amyloid beta protein folds incorrectly due to pathological changes long before the first symptoms occur.

A team of researchers headed by Klaus Gerwert from Ruhr-University Bochum successfully diagnosed this misfolding using a simple blood test. As a result, the disease could be detected approximately eight years before the first clinical symptoms occur.

A lady suffering from Alzheimer’s. Flickr

But experiments showed that the test was not suitable for clinical applications as the test provided false positive diagnoses for nine per cent of the study participants.

In order to increase the number of correctly identified Alzheimer’s cases, the researchers have now introduced the two-tier diagnostic method.

To this end, they use the original blood test to identify high-risk individuals. Subsequently, they add a dementia-specific biomarker, namely tau protein, to run further tests with those test participants whose Alzheimer’s diagnosis was positive in the first step.

Also Read- 15 Dead, Over 15,000 Infected by Dengue in Sri Lanka

If both biomarkers show a positive result, there is a high likelihood of Alzheimer’s disease, said the study published in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.

“Through the combination of both analyses, 87 of 100 Alzheimer’s patients were correctly identified in our study,” Gerwert said.

“Now, new clinical studies with test participants in very early stages of the disease can be launched,” Gerwert added. (IANS)