The Cross-Border Biotech Blog

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

Friday Science Review: May 27, 2011

Functioning Neurons from Canine Embryonic Stem Cells

University of Guelph ♦ University of Toronto ♦ Published in PLoS ONE, May 17, 2011

Scientists have successfully created functioning neural cells from canine embryonic stem cells (ESCs). The protocol used was similar to those used to create neural stem cells from human ESCs. In order to produce neural cells, ESCs were subjected to treatment with epidermal growth factor (EGF) or the signaling molecule Noggin. In both cases, treatment led to the formation of neural stem/progenitor cells expressing the neural lineage marker SOX-2. After priming these neural stem cells, continuing differentiation in the presence of specific growth factors at low dose led to the formation of a diversity of different canine neural cells including oligodendrocytes and astrocytes.

In order to test the functional maturity of the ESC-derived neural cells, researchers grew them along with primary canine fetal cells and astrocytes and then took patch-clamp recordings; a method that can measure action potentials as they fire down the length of the neuron. These recordings showed that the stem cell-derived neurons received inhibitory and excitatory synaptic inputs similar to those observed in functioning neural cells. This protocol provides a necessary proof-of-concept and suggests that the canine could potentially be used as a clinically relevant animal model to improve the quality of data gathered in preclinical studies of stem cell transplantation.

The Protein Localizome

University of British Columbia ♦ Published in PLoS ONE, May 17, 2011

In a particularly eloquent study, researchers have exploited a specific cell type in the nematode worm, C. elegans, in order to begin elucidating the cellular location of proteins. Studies of protein localization are of great value to the scientific community as localization and function are often associated. The large size of the body wall muscle cells in C. elegans and the degree of order exhibited by the sarcomeres within, provide an excellent stage for experimentation and discovery of protein position.

In the beginning of what could become a complete protein “localizome”, researchers unveiled the location of 227 proteins. They achieved this by tagging proteins with green flourescent protein, a molecule that can be observed using flourescence microscopy. The localizations of proteins investigated, orthologs and homologs of human proteins, were largely unknown as no data was available on their precise positioning in the cell. Researchers observed 14 sub-cellular localization patterns in addition to discrete localizations. It is expected that this data will be useful in understanding muscle sarcomere assembly and function, and be applicable in the development of therapeutics for skeletal muscle diseases in humans.

Ultra-Sensitive Detection of Infectious Agents in Human Tissue

Genome Sciences Centre ♦ University of British Columbia ♦ Published in PLoS ONE, May 13, 2011

With the advent of massively parallel sequencing technology it is possible to detect as little as a few RNA transcripts in a sample of human tissue. This technology can analyze an entire transcriptome and pick out the needles in the haystack, so to speak, by identifying low abundance transcripts. In this work researchers describe an approach to troll large sequence data sets for microbial sequences. The impressive part is the sensitivity of the platform. Researchers sequenced RNA libraries containing decreasing quantities of an RNA-virus and found that viral transcripts could be detected at frequencies of less than one in a million. When as much as 20% of cancers are caused by infectious agents, a technology of this nature could have great utility as a diagnostic platform and is certainly more efficient than the traditional culture-based method for identifying infection.

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