Accelerating Stem cell generation

Hanna, et al. at Rudolf Jaenisch’s lab in MIT have discovered an approach to speed up generation of induced pluripotent cells (iPS), importantly with efficiency rate approaching ~ 100%. Low efficient rate of transformation was one of the biggest obstacle so far in iPS creation. In a news story at nature.com, lab reported to develop a sophisticated system to study reprogramming using genetically  identical mouse immune cells that contain additional copies of four genes (namely, Oct4, Sox2, Klf4 and c-Myc) required for reprogramming. I’ve yet to read details of this system. In brief, using this four genes and their system, they document nearly all cells being transformed to iPS at variable rate of cell division – some transforming early and other at late time-point. Mechanism of variable rate transformation is unclear but this means that all adult cells can be reprogrammed and reprogramming is a continuous dynamic process rather possible cessation after certain time-period in a given cell with those four reprogramming genes. Further, investigating role of oncogenes in iPS, they showed that inhibition of the p53/p21 pathway or over-expression of Lin28 increased the cell division rate and resulted in an accelerated kinetics of iPS cell formation. Interesting to learn, Nanog over-expression transformed cells into iPS at faster rate without significantly affecting cell division, implying cell-division independent mechanisms of reprogramming – yet to be discovered! Team is investigating role of epigenetic events in cell-division dependent and independent models of adult cell reprogramming.

 

Related resources:

1. Abbott A, Faster route to stem-like cells, Nature News 10.1038/news.2009.1070 (8-Nov-2009)

2. Hanna J, et al., Direct cell reprogramming is a stochastic process amenable to acceleration, Nature AOP: 10.1038/nature08592 (8-Nov-2009)

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Bob and his cancer world!

Dr Weinberg presenting annual Albright symposium lecture on Cancer World at Harvard Medical School
Samir

This email is sent via my mobile phone. Please pardon the brevity and any typos.

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Reprogramming The Cell: Part 6 | First live mammalian body from iPS

Nature magazine has just released news about two independent studies in China documenting first successful creation of live mammalian body (mice) from induced pluripotent cells (iPS) derived from mouse fibroblasts. The mouse was named Xiao Xiao or 'Tiny'. Success rate of one team was 1.1% and 3.5% for another. Recent studies showed gene expression signature difference between embryonic stem cells (ESCs) and iPS which means iPS cells behave and act differently than ESCs even though end result is creation of entire mammalian body. This property is important to be taken into account of possible benefits or adverse events associated with iPS use in therapeutic cloning. Ethical concerns would now be more amplified about possible use of iPS in human cloning.
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Further reading: 

1. Nature News: David Cyranoski, Mice made from induced stem cells, Published online 23 July 2009 | Nature | doi:10.1038/460560a

2. Xiao-yang Zhao, et al., iPS cells produce viable mice through tetraploid complementation, Nature advance online publication 23 July 2009 | doi:10.1038/nature08267

3. Kang Lan, et al., iPS Cells Can Support Full-Term Development of Tetraploid Blastocyst-Complemented Embryos, Cell Stem Cell 23 July 2009 | doi:10.1016/j.stem.2009.07.001
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Ideas @ MIT

Following are two of many projects at MIT which are drawing much attention and promise science has to offer in coming years.

1. Sixth Sense – WUW Wear Ur World by Pranav Mistry, Pattie Maes media lab.

A TED talk showing a wearable device with a projector worth $  350 that paves the way for profound interaction with our environment. Imagine "Minority Report" and then some. More at TED talk video.

 

2. Virus-powered lithium battery by Angela M. Belcher’s lab

Three years ago, Belcher’s lab reported genetically engineered  viruses that could build an anode by coating themselves with cobalt oxide and gold and self-assembling to form a nanowire. More challenging task was to generate green cathode terminal which needs to be more conductive in contrast to relative non-conductive property of biological candidates for such cathode terminal. Now, same team has come up with a novel biological cathode by genetically engineered viruses that first coat themselves with iron phosphate, then grab hold of carbon nanotubes to create a network of highly conductive material. Connecting these cathode and anode: Voila! Virus-powered lithium ion battery! Besides being green alternative to existing technology, such batteries are light-weight and could be charged and discharged at least 100 times without losing any capacitance. Team is working currently to develop manganese phosphate and nickel phosphate based prototype to match and then possibly to overcome current battery standards. Wow, isn’t it?

 

Additional reading:

1. MIT Press release: New virus-built battery could power cars, electronic devices, Apr 2, 2009

2. Lee YJ, Belcher AM, et al., Fabricating Genetically Engineered High-Power Lithium Ion Batteries Using Multiple Virus Gene, Science 10.1126/science.1171541 (Apr 2, 2009)

3. Nam KT, Belcher AM, et al., Virus-Enabled Synthesis and Assembly of Nanowires for Lithium Ion Battery Electrodes, Science 312 (2006):885-888, DOI: 10.1126/science.1122716

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Image copyrighted by MIT, Cambridge MA USA

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