The Cross-Border Biotech Blog

Biotechnology, Health and Business in Canada, the United States and Worldwide

Friday Science Review: November 26, 2010

Ivermectin Nails Neurotransmission in Brugia malayi

McGill University

Published in PNAS, November 16, 2010

Well over 100 million people are currently infected with Brugia malayi, a microscopic nematode that causes lymphatic filariasis. Infection can eventually lead to the chronic inflammatory disease known as elephantiasis. In an effort to better understand this parasitic creature Dr. Timothy Geary and his team in the Institute of Parasitology at McGill University took a closer look at its glutamate-gated chloride channels (GluCls). These channels are localized to a very specific muscle structure surrounding an excretory vesicle in B. malayi and are essential for controlling protein release. Researchers show that ivermectin, a broad-spectrum anti-parasitic medication commonly deployed to reduce B. malayi infection, directly interferes with GluCl function preventing excretion of proteins from this excretory site. As protein excretion is known to be a very important aspect of the parasites survival system, allowing it to evade the immune system of the host it colonizes, researchers attribute the effectiveness of ivermectin to its ability to interfere with neurotransmission at GluCls. Screening for additional compounds that interact with GuCls could provide new treatment paradigms for B. malayi infection in the future.

Prion Disease: A Sticky Situation

University of Toronto ♦ University of British Columbia

Published in PNAS, November 16, 2010

Prion diseases include the infamous mad-cow disease (bovine spongiform encephalopathy), fatal familial insomnia, and the human disease ‘kuru’. The latter of these, believe it or not, being caused by human cannibalism and documented in small tribes located in Papua New Guinea that partake in strange funeral rituals following the deaths of relatives (I’ll spare you the details). These neurodegenerative diseases are often terminal and are caused by proteins, known as a prions, that have a propensity to aggregate together forming dangerous plaques that ultimately destroy neural tissue. Not all prion proteins are bad however, their behaviour depends on structural state. A switch from the α-helical conformation to the pathological β-form leads to rogue prion proteins that ‘stick’ to one another. Researchers at the University of Toronto were curious as to why animals of different sizes have different susceptibilities to prion diseases. In this study led by Dr. Avijit Chakrabartty, scientists used X-ray crystallographic structure analysis and a rabbit model to identify cellular mechanisms that explain the rabbit’s relative immunity to prion diseases. A helix-capping motif found in rabbits prevents folding of prion proteins into the pathological state. Findings like these, elucidating the underlying mechanisms driving transformation to the pathological state, should help us brainstorm future therapies for these deadly diseases.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 129 other followers