Cells Weekly – February 2, 2014

by Alexey Bersenev on February 2, 2014 · 0 comments

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Cells Weekly is a digest of the most interesting news and events in stem cell research, cell therapy and regenerative medicine. Cells Weekly is posted every Sunday night!

1. Discussions on STAP
STAP method for generation of stem cells was a biggest news this week. Today, I just would cite a couple of blog posts and give links to ongoing discussions. First of all, interview with Charles Vacanti – a senior author of STAP study. Second, very interesting quote from Mainichi:

Obokata now leads a lab at an exceptionally young age in Japan, where female scientists are said to have a tough time.

Third, Teisha Rowland from Biology Bytes blog makes a good point:

That said, just last summer researchers at Salk Institute for Biological Studies reported being able to turn cells into iPSCs using a mixture of chemicals instead of genes. So, ultimately, STAP cells might not really have an advantage in this respect afterall.

Now STAP discussions:
Discussion on post-publication peer review site PubPeer
Discussion on Nature News coverage
Discussion on Knoepfler Lab Stem Cell Blog

I’d highly encourage to participate in discussions!

2. Tweets from Cell & Gene Therapy Forum 2014
This week I was tweeting and blogging from annual Phacilitate Cell & Gene Therapy Forum. You can read tweet here, including top 10 events in cell therapy industry in 2013. Also read my blog posts from Stem Cells as Discovery & Research Tools conference (as a part of Cell & Gene Therapy Forum):
Cell and Gene Therapy Forum 2014 – Stem cells for drug discovery
Stem Cells as Research tools – considerations for stem cell banks

3. Introducing StemBios cells
While whole world was busy watching STAP, researchers from start-up company StemBios Technologies Inc, described their own adult multipotent stem cells or spore-like cells or VSEL-like stem cells. They called them StemBios cells:

We are the first to demonstrate that stem cells smaller than 6 µm can differentiate both in vivo and in vitro. In the future, we hope that SB cells will be used therapeutically to cure degenerative diseases.

Would somebody evaluate?

4. Fast cycling progenitor cells are privileged for reprogramming
The discussion about stochastic versus nonstochastic models of cell reprogramming to pluripotency is still on. This week, Cell published very interesting study, which supports nonstochastic model:

Subsets of murine hematopoietic progenitors are privileged whose progeny cells predominantly adopt the pluripotent fate with activation of endogenous Oct4 locus after four to five divisions in reprogramming conditions. Privileged cells display an ultrafast cell cycle of ∼8 hr. In fibroblasts, a subpopulation cycling at a similar ultrafast speed is observed after 6 days of factor expression and is increased by p53 knockdown. This ultrafast cycling population accounts for >99% of the bulk reprogramming activity in wild-type or p53 knockdown fibroblasts.

Nice study, linked elite model of reprogramming to cell cycle.

5. Direct reprogramming of human fibroblasts into retinal cells
Direct reprogramming magic continues! This week, researchers from Salk Institute published a protocol for reprogramming human fibroblasts into retinal pigmental epithelial (RPE) cells:

By monitoring a human RPE specific Best1::GFP reporter, we report the conversion of human fibroblasts into RPE lineage using defined sets of transcription factors.

6. Adipose autologous MSC are useless in multiple sclerosis model
Bruce Bunnell’s team continues to impress me with interesting work. This week I came across their new study, which demonstrated that autologous ex vivo expanded adipose tissue-derived mesenchymal stromal cells (MSC) could be useless in mouse model of multiple sclerosis:

In vivo, infusion of wild type ASCs significantly ameliorate the disease course, autoimmune mediated demyelination and cell infiltration through the regulation of the inflammatory responses, however, mice treated with autologous ASCs showed no therapeutic improvement on the disease progression.

Yes, clinical use of it is way ahead, but, based on preclinical data, we should be very cautious about it (hint to CellTex-like clinics).

7. Conversion of tumor cells to normal cells
Reprogramming magic continues! Japanese researchers reported for the first time, reprogramming of hepatoma cells into normal liver cells in vivo, using miRNA:

We are the first to demonstrate the loss of malignant properties in cancer cells in vivo through the expression of a single microRNA (miRNA). This miRNA successfully converted 293FT and hepatoma cells to hiPSC-like cells. The regulation of malignancy by miR-520d appears to be through the conversion of cancer cells to normal stem cells, maintaining p53 upregulation.

8. New feeder-mimetic to define embryonic stem cell culture
Combination of recombinant laminin-521 and E-cadherin allowed robust clonal culture of human embryonice stem cells. A study was out this week:

This matrix allows clonal derivation, clonal survival and long-term self-renewal of hES cells under completely chemically defined and xeno-free conditions without ROCK inhibitors.

This is good news for all ES cell culturists!

9. Interview with Masayo Takahashi
In the light of world’s first human study for iPS cell-derived product implantation, Masayo Takahashi is all over the place. This week, New Scientist interviewed her:

How confident are you that the pilot will be a success?
Very confident. We have trialled this intervention on mice, rats and monkeys, and observed no tumours.

I love her confidence!


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