Scientists develop very early stage human stem cell lines for first time

cjb250 — Fri, 04 Mar 2016 08:41:37 +0000

As well as a potential source of stem cells for use in regenerative medicine, the technique could open up new avenues of research into disorders such as Down鈥檚 syndrome.

探花直播ability to derive na茂ve stem cells has been possible for over thirty years from mouse embryos, using a technique developed by Sir Martin Evans and Professor Matthew Kaufman during their time at Cambridge, but this is the first time this has been possible from human embryos.

Human pluripotent stem cells for use in regenerative medicine or biomedical research come from two sources: embryonic stem cells, derived from fertilised egg cells discarded from IVF procedures; and induced pluripotent stem cells, where skin cells are reprogrammed to a pluripotent form. However, these cells are already 鈥減rimed鈥� for differentiation into specific cell types. In contrast, all instructions have been erased in na茂ve cells, which may make it easier to direct them into any cell type of interest.

Recently na茂ve-like human induced pluripotent stem cells have been created by reprogramming but it has been unknown whether they can also be obtained directly from the human embryo.

When an egg cell is fertilised by a sperm, it begins to divide and replicate before the embryo takes shape. Around day five, the embryonic cells cluster together and form a structure called the 鈥榖lastocyst鈥�. This occurs before implantation into the uterus. 探花直播blastocyst comprises three cell types: cells that will develop into the placenta and allow the embryo to attach to the womb; and cells that form the 鈥榶olk sac鈥�, which provides nutrients to the developing foetus; and the 鈥榚piblast鈥� comprising the na茂ve cells that will develop into the future body.

In research published today in the journal Stem Cell Reports, scientists from the Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute managed to remove cells from the blastocyst at around day six and grow them individually in culture. By separating the cells, the researchers in effect stopped them 鈥榯alking鈥� to each other, preventing them from being steered down a particular path of development.

鈥淯ntil now it hasn鈥檛 been possible to isolate these na茂ve stem cells, even though we鈥檝e had the technology to do it in mice for thirty years 鈥� leading some people to doubt it would be possible,鈥� explains Ge Guo, the study鈥檚 first author, 鈥渂ut we鈥檝e managed to extract the cells and grow them individually in culture. Na茂ve stem cells have many potential applications, from regenerative medicine to modelling human disorders.鈥�

Na茂ve pluripotent stem cells in principle have no restrictions on the types of adult tissue into which they can develop, which means they may have promising therapeutic uses in regenerative medicine to treat devastating conditions that affect various organs and tissues, particularly those that have poor regenerative capacity, such as the heart, brain and pancreas.

Dr Jenny Nichols, joint senior author of the study, says that one of the most exciting applications of their new technique would be to study disorders that arise from cells that contain an abnormal number of chromosomes. Ordinarily, the body contains 23 pairs of identical chromosomes (22 pairs and one pair of sex chromosomes), but some children are born with additional copies, which can cause problems 鈥� for example, children with Down鈥檚 syndrome are born with three copies of chromosome 21.

鈥淓ven in many 鈥榥ormal鈥� early-stage embryos, we find several cells with an abnormal number of chromosomes,鈥� explains Dr Nichols. 鈥淏ecause we can separate the cells and culture them individually, we could potentially generate 鈥榟ealthy鈥� and 鈥榓ffected鈥� cell lines. This would allow us to generate and compare tissues of two models, one 鈥榟ealthy鈥� and one that is genetically-identical other than the surplus chromosome. This could provide new insights into conditions such as Down鈥檚 syndrome.鈥�

探花直播research was supported by the Medical Research Council, Biotechnology and Biological Sciences Research Council, Swiss National Science Foundation and the Wellcome Trust.

Reference
Guo, G et al. Na茂ve pluripotent stem cells derived directly from isolated cells of the human inner cell mass; Stem Cell Reports; e-pub 3 March 2015. DOI: 10.1016/j.stemcr.2016.02.005

Scientists at the 探花直播 of Cambridge have for the first time shown that it is possible to derive from a human embryo so-called 鈥榥a茂ve鈥� pluripotent stem cells 鈥� one of the most flexible types of stem cell, which can develop into all human tissue other than the placenta.

Until now it hasn鈥檛 been possible to isolate human na茂ve stem cells, even though we鈥檝e had the technology to do it in mice for thirty years 鈥� leading some people to doubt it would be possible

Ge Guo

Colonies of human na茂ve embryonic stem cells grown on mouse feeder cells

探花直播text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

探花直播 of Cambridge - Jenny Nichols

Scientists develop very early stage human stem cell lines for first time