Fresh hurdle for stem cell hunt

-
Previously blogging on the topic of regenerative medicine in Regenerative Medicine Start-Up Created out of ORNL. A Nobel Prize-winning scientist says it could be tougher than first thought to harness the healing power of stem cells in medicine.

It had been hoped a single "master" cell could potentially be used to repair all damage in a single organ. Stem cells may be more varied than previously thought. Professor Mario Capecchi, from the University of Utah, found surprising clues that different stem cells might be working together in the same organ. This means experimental treatments relying on the wrong type might fail.

Professor Capecchi, writing in the Nature Genetics, said the finding suggested stem cell biology could be "more complicated" than previously thought, which could be bad news for patients hoping for the swift arrival of new therapies.

Bmi1 plays an essential part in the self-renewal of hematopoietic and neural stem cells. To investigate its role in other adult stem cell populations, we generated a mouse expressing a tamoxifen-inducible Cre from the Bmi1 locus. We found that Bmi1 is expressed in discrete cells located near the bottom of crypts in the small intestine, predominantly four cells above the base of the crypt (+4 position). Over time, these cells proliferate, expand, self-renew and give rise to all the differentiated cell lineages of the small intestine epithelium. The induction of a stable form of beta-catenin in these cells was sufficient to rapidly generate adenomas. Moreover, ablation of Bmi1+ cells using a Rosa26 conditional allele, expressing diphtheria toxin, led to crypt loss. These experiments identify Bmi1 as an intestinal stem cell marker in vivo. Unexpectedly, the distribution of Bmi1-expressing stem cells along the length of the small intestine suggested that mammals use more than one molecularly distinguishable adult stem cell subpopulation to maintain organ homeostasis.

Do you want to know more? Nature Genetics Published online: 8 June 2008


Comments

Post a Comment

Popular posts from this blog

Sequence Analysis is still sexy:Dual Descriptor Method for Biological Sequence Analysis

-
The emergence of “Systems Biology” in recent years highlights the systematic viewpoint of bio-system modeling. Building on such a background, Dual Descriptor Method, a generic methodology for biological sequence analysis is proposed. From a systematic perspective, Dual Descriptor is defined as a two element set of Composition Weight Map and Position Weight Function which aim at reflecting the composition and permutation information of a sequence. An alternate training algorithm is provided to get an optimum description of the building patterns of the sequences. In this paper , dual descriptor method has been applied to the analysis of two typical problems of molecular biology: gene identification and the prediction of protein function. Satisfactory and insightful results are achieved. Owing to the generality of this methodology, dual descriptor method has wide application perspective for many problems of pattern recognition, especially those involved in “Systems Biology”. Be a part of
Read more

Abbott Laboratories Buys Piramal Healthcare Limited Biz for $3.72B

-
Abbott May 21 announced a definitive agreement with Piramal Healthcare Limited to acquire full ownership of Piramal's Healthcare Solutions business (Domestic Formulations), a leader in the Indian branded generics market, for an up-front payment of $2.12 billion , plus $400 million annually for the next four years, giving Abbott the No. 1 position in the Indian pharmaceutical market. This further accelerates Abbott's emerging markets growth following the recent acquisition of Solvay Pharmaceuticals and announcements last week of Abbott's collaboration with Zydus Cadila as well as the creation of a new stand-alone Established Products Division to focus on expanding the global markets for its leading branded generics portfolio. "This strategic action will advance Abbott into the leading market position in India , one of the world's most attractive and rapidly growing markets," said Miles D. White , chairman and chief executive officer, Abbott. &quo
Read more

List of Cheminformatics Companies & Institutions

-
Accelrys ACD/Labs (Advanced Chemistry Development, Inc.) Afferent Systems Inc. Agilent Technologies Aureus Pharma Barnard Chemical Information Ltd. (John Barnard and Geoff Downs) SEE: digital chemistry Bio-Rad Laboratories BioReason BioSolveIT BlueObelisk.org Bruker Daltonics Inc. Cambridge Crystallographic Data Centre CambridgeSoft Corporation CARB Center for Advanced Research in Biotechnology (NIST/University of Maryland) Cengent Therapeutics (Genes to Leads). Acquired by Inncardio, Inc. Center for Molecular Modeling (NIH) Centre for Molecular and Biomolecular Informatics CMBI (formerly: CAOS/CAMM: Dutch National Center for Computer-Assisted Chemistry and Molecular Modelling) Cerep ChemAxon ChemDiv, Inc. (Chemical Diversity) Chemical Abstracts Service Chemical Computing Group, Inc. Chemical Simulations Group ChemInnovation Software ChemNavigator ChemSW (Chemistry Software for Windows, formerly: WindowChem) Chenomx Inc. CIS Chemical Information System CombiChem.net CompuChem C
Read more