337 replies to this topic

[kevin]

Link: http://www.eurekaler...u-nmo120903.php
Date: 12-12-03


Using green fluroescent protein techniques, researcher have found a way to keep stem cells glowing while their more rapidly dividing progeny become dim thus pointing the way to their hiding place in skin. Very cool.. and I expect very lucrative as well as the stem cells under study can either form new skin OR hair... maybe a cross reference to the Keeping up Appearances thread is coming.. heh..

The system, dubbed "pulse and chase," required development of two different genetically altered mice. In one mouse, a fusion gene (histone H2B-GFP) that can express a green fluorescent protein when cells divide was introduced into a mouse embryo. But in order for the mouse to express this green fusion protein, it needed to be turned on by an "activator" protein. That is where the second mouse came in. The Fuchs lab mated their mouse to one that possessed a second fusion gene (keratin 5-tetracycline-off-activator) that only produces the "activator" protein in the skin epithelial cells. In the final transgenic mice, the glowing histone-H2B-GFP protein was made in all the skin epithelial cells, where it entered the nucleus and bound to DNA. That was the "pulse" part of the formula.

To turn the fluorescent protein off and watch what happened in the "chase," the researchers simply added tetracycline to the mouse food, and no more fluorescent protein was made in the skin. Those cells that rapidly divide soon diluted out their glow and became dim, whereas cells that slowly cycled - the putative stem cells - were the only ones left that glowed brightly. Some cells, the slow-cycling cells, glowed for weeks after others had stopped, says Tumbar.

"After a month the remaining glowing cells, which we predicted to be stem cells, were in the bulge," Tumbar says.

The researchers took those cells out of the bulge, isolated their RNA, and used microarray technology to obtain their "transcriptional profile." (The DNA in genes produces RNA, which codes for protein production). A number of the 150-plus sequences code for proteins that are found on the surface of the slow-cycling stem cells or are secreted by them. Those proteins are new markers that may help find stem cells in human tissue, the researchers say.

The researchers then compared genes found in the skin stem cell niche with those found in blood, neuronal and embryonic stem cells. They found that 40 percent of the genes expressed in slow-cycling skin cells, compared with the genes found in their daughter cells, were also expressed in the other stem cell types. And 80 to 90 percent of the genes expressed in the skin cells were expressed in at least one of the three other stem cell populations.

"This comparison sets the ground for future research regarding similarities between slow-cycling cells and other stem cells," says Tumbar

[Cyto]

Japan allows stem cell research

A Japanese government panel on Friday recommended allowing limited cell research on human embryos, but only if a regulatory body is appointed, according to media reports.

The Cabinet Office's bioethics committee made its recommendation in a mid-term report, the Yomiuri newspaper said on its Web site. It will compile a final report by June 2005 [?] , after holding a public forum on the issue, the daily said.

Phones at the Cabinet Office division in charge went unanswered.

In its report, the panel of experts said it favors the production and use of human embryos only for research to treat serious hereditary diseases.
(Bates: Note thats not a bad thing.)

Japan banned cloning humans in 2001, but approved the use of embryonic cells for experiments only if the cells were taken from those earmarked for fertility treatment that would otherwise be discarded.

[Cyto]

Im sure we can all take 2 seconds to read over this. Talking about the morphological hand in things is a nice change from growth factors.
________________________________________________________________________________
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Stretching changes stem cells' fate

Stretching stem cells can influence whether they turn into fat or bone, say researchers. This might partly explain why exercise strengthens the skeleton.

The group studied mesenchymal stem cells. These dwell in bone marrow and can create new fat, cartilage, muscle and bone. The scientists perched single cells on one of two different growth-enhancing carpets: either squares that gave cells room to stretch out, or tiny dots that reined them in.

Stretched cells were more likely to become bone cells, the group found; huddled ones became fat. Forcing the cells to tighten up by injecting a gene called RhoA, also created bone cells. Discovering the molecules involved is "really cool", says lead researcher Christopher Chen of Johns Hopkins University in Baltimore, Maryland.

Walking and jogging, which help to strengthen bones, might place bone-marrow stem cells under stress and trigger the production of bone cells, Chen speculates. He will present the results at this week's American Society for Cell Biology meeting in San Francisco.

Cell biologists know that squeezing or stretching can determine whether cells die, divide or transform into another cell type. But few such experiments have been done on stem cells that produce many tissue types and are of interest to doctors as a potential way to repair the body.

Many scientists are searching for the molecules that drive a stem cell to make muscle, say, instead of blood; RhoA might be one of these. But to build new bone or tendon, stem cells may also need the correct position or orientation, says cell biologist Donald Ingber of Harvard Medical School in Boston, Massachusetts. "There's mechanics as well as chemistry," he says.

Ingber points out that many medical treatments already work because they place cells under tension: such as implanting a sac under the skin to grow new material for a graft, or physical therapy to heal strains. "These ideas have been around for ages, but only recently they've come into vogue," Ingber says.

Edited by CarboniX, 18 December 2003 - 11:31 PM.

[Cyto]

Assembly approves bill to authorize stem cell research

TRENTON, N.J. -- The Assembly approved a bill Monday that would permit stem cell research despite opposition from conservatives that it could promote human cloning.

While there was debate over the scope of the legislation, the measure passed by 41-31 with seven members abstaining. The legislation will now go to the desk of Gov. James E. McGreevey, who has indicated he would sign a stem cell research bill.

Organizations that sponsor research for terminal illnesses praised the bill as a major step forward for finding cures and lessening painful symptoms of deadly diseases. If the bill becomes law, New Jersey will become the second state in the nation to permit stem cell research.

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Chemical Gradient Steers Nerve Growth In Spinal Cord (The study focused on commissural neurons, which are found in the spinal cord.)

A research team at the University of Chicago has discovered a crucial signaling pathway that controls the growth of nascent nerves within the spinal cord, guiding them toward the brain during development.

"This is the first guidance mechanism that regulates growth of nerve cells up and down the spinal cord," said Yimin

"This is exciting to scientists because these neurons are the primary model system we use to understand assembly of the nervous system," he said. "It's exciting to clinicians because it could help regenerate damaged axons in the central nervous system."

Many researchers are studying ways to use stem cells to regenerate damaged tissues. Even if stem cells can be successfully "trained" to become the type of neurons needed and transplanted into the damaged central nervous system, "they still need to be guided precisely to their targets in order to rebuild the connections," explained Zou. "Understanding how the brain and spinal cord are connected during embryonic development should give us clues about how to repair these connections in adulthood."

[Cyto]

Scientists find possible cure for Parkinson's

Park said Tuesday that he transplanted embryonic human stem cells into disease-infected rats. The cells had been genetically modified to produce dopamine beforehand. After the transplant, the stem cells developed into dopamine-producing cells in the rats with no apparent immune rejection, leading to the return of normal motor skills.

Park said the research would be published in the Dec. 19 issue of "Neuroscience Letters," a research journal.

He said that this is the first time that genetically modified human embryonic stems cured certain a disease in rats. The Korean scientists plan to conduct the same kind of test on primates jointly with Yerkes Regional Primate Research Center at Emory University in the United States in the near future."

So far, some overseas studies have only shown that embryonic human stem cells, after being differentiated, can be successfully transplanted into the brain of normal rats.

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'Humanised' organs can be grown in animals

Mmmm, don't think we should worry about this anytime soon. My major problem is sheep cell contamination and possible stem cell fusion with sheep stem cells. Which can occur in murine models.

[Cyto]

Nomadic outposts of transplanted stem cells tracked in Stanford study
Stem Cells Like to Travel

We want to know why the process is so dynamic with unpredictable fates for the initial stem cell foci," says Cao. "There's no obvious reason for the stem cells to leave what appears to be a perfectly good place to homestead and proliferate."

For the study, mice with bone marrow destroyed by radiation were injected with stem cells modified with luciferase.

The researchers then gave the mice doses of the molecule luciferin to activate the luciferase enzyme and cause the stem cells to glow.

The researchers were surprised at how much the pattern varied—in many cases one location would initially house a healthy population of glowing stem cells, only to have that population fade over time while daughter cells set up camp at a distant location.

When the researchers took stem cells from sites within one transplanted animal and put them into a second mouse lacking bone marrow, those stem cells once again seemed to take a random path to new niches.

The findings could help guide transplantation procedures using stem cells such as those for neurons. "We can monitor the fate of those stem cells and help evaluate transplantation protocols," says Cao.

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Membrane properties of rat embryonic multipotent neural stem cells

Overall, our results show that fetal NSCs exhibit a unique signature that can be used to determine their location and assess their ability to respond to their environment.

[Cyto]

I stayed up! And what did I lay my eyes on? A new issue of Stem Cell Journal!

Now, I'm sure there are some other neat ones but here is the one I like right now.

Chemokines Promote Quiescence and Survival of Human Neural Progenitor Cells Abstract

Many cell types in the brain express chemokines and chemokine receptors under homeostatic conditions, arguing for a role of these proteins in normal brain processes. Because chemokines have been shown to regulate hematopoietic progenitor cell proliferation, we hypothesized that chemokines would regulate neural progenitor cell (NPC) proliferation as well. Here we show that chemokines activating CXCR4 or CCR3 reversibly inhibit NPC proliferation in isolated cells, neurospheres, and in hippocampal slice cultures. Cells induced into quiescence by chemokines maintain their multipotential ability to form both neurons and astrocytes. The mechanism of chemokine action appears to be a reduction of extracellular signal-related kinase phosphorylation as well as an increase in Reelin expression. The inhibitory effects of chemokines are blocked by heparan sulfate and apolipoprotein E3 but not apolipoprotein E4, suggesting a regulatory role of these molecules on the effects of chemokines. Additionally, we found that the chemokine fractalkine promotes survival of NPCs. In addition to their role in chemotaxis, chemokines affect both the survival and proliferation of human NPCs in vitro. The presence of constitutively expressed chemokines in the brain argues that under homeostatic conditions, chemokines promote survival but maintain NPCs in a quiescent state. Our studies also suggest a link between inflammatory chemokine production and the inhibition of neurogenesis.

Interesting results. We have inhibition of asymetrical progenation (don't know what that means? find the SACK post) yet the increase of Reelin has been shown to promote long terminal potentiation in hippocampal studies (source upon request). Also chronic back pain has been shown to actually suppress neuronal growth. I think this is great paper to help clear up and further understand neuronal mechanisms.

[Cyto]

Reversine

Oh yea, thats cool.

A group of researchers from The Scripps Research Institute has identified a small synthetic molecule that can induce a cell to undergo dedifferentiation--to move backwards developmentally from its current state to form its own precursor cell.
This compound, named reversine, causes cells which are normally programmed to form muscles to undergo reverse differentiation--retreat along their differentiation pathway and turn into precursor cells.

These precursor cells are multipotent; that is, they have the potential to become different cell types. Thus, reversine represents a potentially useful tool for generating unlimited supply of such precursors, which subsequently can be converted to other cell types, such as bone or cartilage.

"This [type of approach] has the potential to make stem cell research more practical," says Sheng Ding, Ph.D. "This will allow you to derive stem-like cells from your own mature cells, avoiding the technical and ethical issues associated with embryonic stem cells."

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Neural progenitors find VEGF attractive

Blood vessels and neural stem cells can be led to their targets by the same factor, say Zhang et al. on page 1375. The factor, vascular endothelial growth factor A (VEGF), is known as a major inducer of angiogenesis. Zhang et al. show that it is also a powerful attractant for immature neural progenitor cells. In the developing mammalian brain, it may be used when both neural stem cell migration and blood vessel growth must head for the same brain region.

[Cyto]

Stem-cell 'secret of youth' found

One problem is that scientists don't yet know how to control the cells' transformations into other types. Another is that the cells cannot be grown without help from mouse cells, which means that they could be contaminated with mouse proteins.  Ali Brivanlou of Rockefeller University in New York says that he and his colleagues may have found a partial solution to these problems. Brivanlou treated ES cells with a chemical, nicknamed BIO, from a sea snail.

BIO stopped ES cells turning into specialized adult cells, Brivanlou and his colleagues found. BIO works by activating a set of protein signals - called the Wnt pathway - in the ES cells.  The Wnt pathway is known to be involved in development. Earlier this year, researchers reported that it also prevents blood-forming stem cells from turning into other cell types2.  The discovery could be useful to scientists who are trying to make therapies based on stem cells. By controlling the Wnt pathway, they could tell the cells when to stay young, and when to specialize.

Using chemical compounds such as BIO might also eliminate the need for mouse support cells, which normally ooze proteins that stop stem cells specializing. Many research groups are looking for alternative ways to wean human cells off mouse feeder cells.  So far, Brivanlou has only monitored the cells for a few cycles of division, so he doesn't know how long BIO can sustain them. But he hopes that further studies will help scientists discover how to manipulate stem cells at will.

"If we want to make stem cells into therapies, we're going to need cell lines that were never grown in any foreign proteins," Brivanlou says. "This work should help us take stem cells into that clinical setting."

[Mind]

I just wanted to posts these 2 articles because I perceive a link between mechanical and chemical interactions of cells, including stem cells. One is a repeat of a previous post but I think it has more importance when considering the tensegrity paper.

Stretching changes stem cells' fate

Tensegrity II. How structural networks influence cellular information processing networks.

When it comes to cell development, it seems to me that the shape of a cell's environment (and thus the eventual shape of the cell itself) is just as important as its genetic code.

[Cyto]

Homegrown embryonic stem cells in offing

Beginning next month, a national institute will start providing domestically produced human embryonic stem cells -- a move likely to accelerate Japanese research into the production of tissue and organs for medical use.

Harvard Inspiration? Who knows...

[Lazarus Long]

This article sounds like it is very much along the lines of the one you have listed above but I am going to include it anyway.


http://news.bbc.co.u...lth/3346063.stm
Hope for new source of stem cells
Wednesday, 24 December, 2003

US scientists have found a way to turn adult cells back into immature cells with the potential to become many different types of tissue. The breakthrough by Scripps Research Institute in California could provide a non-controversial way to grow tissue for medical treatments.

The use of immature "stem" cells holds great promise as a treatment for paralysis or diseases like Parkinson's. But some oppose use of the most potent cells because they come from embryos.

The key to the new development is a small molecule called reversine.

The researchers found that it caused cells which are normally programmed to form muscles to turn back into immature cells whose final state is not sealed. Thus they could become many different types of tissue such as bone or cartilage. Researcher Dr Sheng Ding said: "This [type of approach] has the potential to make stem cell research more practical.

"This will allow you to derive stem-like cells from your own mature cells, avoiding the technical and ethical issues associated with embryonic stem cells."

Replace lost cells

Stem cells have huge potential because in theory they can provide doctors with the ability to produce cells that have been permanently lost by a patient.

For instance, they could potentially be used to generate new brain cells to replace those lost in patients with Parkinson's disease, or pancreatic islet cells to replace those destroyed by the immune system of people with diabetes.

Scientists believe it would be best to use stem cells taken from a patient's own body. This would avoid possible complications caused by the immune system attacking what it perceives as foreign invaders.

However, in general it has proven very difficult to isolate and propagate stem cells from adults.

Embryonic stem cells offer an alternative. However, their use is fiercely opposed by the "pro-life" movement, and scientists face problems controlling their subsequent development.

Lessons from nature

The latest approach represents a potentially more practical alternative. In humans, the only organ that can regenerate itself - possibly by reversing the developmental state of its cells - is the liver.

But examples of the developmental reversal of cells have been seen in nature.

For instance, some amphibians the have the ability to regenerate severed body parts by turnings cells at the site of the wound back into an immature state.

The Scripps team says much more work is needed to understand how reversine works, and to refine the process. They have warned that tissue regeneration using this method is still years away at best.

The research will be published in the Journal of the American Chemical Society.

[Cyto]

ViaCell gets $20M investment and new collaboration deal from Amgen

ViaCell Inc. of Boston has entered into a collaboration and license agreement with California’s Amgen Inc. in the field of cellular therapy. Amgen will also purchase $20 million of equity in ViaCell as part of the transaction.

The agreement provides ViaCell with licenses to certain cellular growth factors and provides Amgen with the right to collaborate with ViaCell to develop and commercialize cellular therapy products resulting from the collaboration.

"Amgen's growth factors are critical for the development and manufacture of our cellular therapy products,” said Marc Beer, chairman and chief executive officer of ViaCell, in a statement. "In addition to the growth factors, Amgen has a tremendous amount of knowledge about cell manufacturing and development. The combination of ViaCell's technology with Amgen's growth factors, knowledge and capital will allow ViaCell to explore cell therapy as meaningful therapeutics more rapidly."

[Cyto]

Way to Grow Young Nerve Cells Found
A big surprise: Young nerve cells can rewind their developmental clocks (Better Article)

A team led by researchers at the New York University School of Medicine found that by manipulating the gene, they could trick the brains of embryonic mice into producing cortical cells that belonged to an earlier part of development.

"Consequently, while some populations of stem cells exist in the adult brain, these cells are restricted to producing only a subset of cell types," Fishell says. "If one's goal is to produce cells for replacement therapy, some method must be found to turn back the clock and allow adult stem cells to give rise to the wide variety of cells made during normal brain development."

The study appears in the Jan. 2 issue of Science.

Umm, didn't give the gene name. Guess we have to wait for a day. [wis]

Never mind HealthCentral.com just stinks. Its through ablation of the Foxg1 gene.

[Cyto]

IGF-I instructs multipotent adult neural progenitor cells to become oligodendrocytes

Adult multipotent neural progenitor cells can differentiate into neurons, astrocytes (IE: synaptocytes), and oligodendrocytes (CNS myelin producers) in the mammalian central nervous system, but the molecular mechanisms that control their differentiation are not yet well understood. Insulin-like growth factor I (IGF-I) can promote the differentiation of cells already committed to an oligodendroglial lineage during development. However, it is unclear whether IGF-I affects multipotent neural progenitor cells. Here, we show that IGF-I stimulates the differentiation of multipotent adult rat hippocampus-derived neural progenitor cells into oligodendrocytes. Modeling analysis indicates that the actions of IGF-I are instructive. Oligodendrocyte differentiation by IGF-I appears to be mediated through an inhibition of bone morphogenetic protein signaling. Furthermore, overexpression of IGF-I in the hippocampus leads to an increase in oligodendrocyte markers. These data demonstrate the existence of a single molecule, IGF-I, that can influence the fate choice of multipotent adult neural progenitor cells to an oligodendroglial lineage.

IGF-I is also shown to be therapeutically useful in treating glutamate excitotoxicity (triggers too much Ca2+ intake leading to producing peroxynitrites or overloading mitochondria's Ca buffer).

[Cyto]

Mayo researchers observe genetic fusion of human, animal cells -may help explain origin of AIDS

In the research reported today, Mayo Clinic investigators implanted human blood stem cells into fetal pigs. The pigs look and behave like normal pigs. But cellular analysis shows they have some human blood cells, as well as some cells that are hybrids -- part human, part pig -- in their blood, and in some of their organs. Molecular examination shows the hybrid cells have one nucleus with genetic materials from both the human and the pig. Importantly, the hybrid cells were found to have the porcine endogenous retrovirus, a distant cousin of HIV, and to be able to transmit that virus to uninfected human cells.

[Cyto]

Organ Recovery Systems Receives Three Grants to Fund New LifePort Organ Transportation Devices & Cryopreservation Methods

The third grant awarded was distributed through the National Heart, Lung and Blood Institute to study the preservation of myocardial tissue engineered constructs:

-- The goal of this research is to develop a process to provide long-term storage methods for tissue engineered myocardial cells. Congestive heart failure affects an estimated 5 million patients in the United States. In many of these patients the heart muscle cells, myocardial cells, become damaged. Since these cells are unable to regenerate therapeutic approaches using myocardial cells or stem cells that give rise to myocardial cells are being developed. The technology development proposed in this grant will enable the emerging cardiac tissue engineering industry for repair damaged hearts.

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Feeder-free System For Maintaining Pluripotency In Embryonic Stem Cells Pioneered

This new system for maintaining pluripotency could be a providential break for basic researchers and clinicians investigating the potential of HESCs, as it is a potential first step in providing an unlimited source of tissue transplant if HESCs' potential comes to fruition in clinical medicine.

It works like this: a newly purified compound from the purple dye of marine red mollusks -- called 6-bromoindirubin-3'-oxime, or by its working acronym, "BIO"-- has been shown by Rockefeller scientists to indirectly activate a crucial gene expression mechanism, called the Wnt signaling pathway, in embryonic cells. Wnt signaling occurs when the new compound inhibits a specific protein kinase in embryonic cells, called GSK-3.

This enzyme plays an essential role in many normal and disease states from development to neurodegenerative disorders. It is involved in numerous pathways including a highly conserved and important one called the Wnt signaling pathway. When GSK-3 is inactivated, Wnt is active. Chemical inhibition of GSK-3 thus mimics activation of Wnt and this keeps HESCs in an active, undifferentiated state -- one of the crucial basic qualities of embryonic stem cells.

"We know precisely how this compound works -- that is, on which enzymes and pathways -- and that it is very controllable," says Brivanlou. "This knowledge makes the compound useful not only in stem cell research but also, as we are already seeing in the lab, numerous other research areas."

[Cyto]

Scientists Restore Crucial Myelin In Brains Of Mice

The team studied 44 mice that were born without any myelin wrapped around their brain cells. Within 24 hours of their birth, scientists injected cells that become oligodendrocytes –myelin-producing cells – into one precisely selected site in the mice.

Scientists found that the cells quickly migrated extensively throughout the brain, then developed into oligodendrocytes that produced myelin which coated or "ensheathed" the axons of cells in the brain.

"These cells infiltrate exactly those regions of the brain where one would normally expect oligodendrocytes to be present," says Goldman. "As they spread, they begin creating myelin which wraps around and ensheaths the axons."

Goldman says that while scientists have used other methods during the past two decades to remyelinate neurons in small portions of the brains of mice, the remyelination seen in the Nature Medicine paper is much more extensive. He estimates that about 10 percent of the axons in the mouse brains were remyelinated, compared to a tiny fraction of 1 percent in previous studies.

[Cyto]

Singapore to open S$15m public cord-blood bank

Singapore is getting its first public cord-blood bank: a new S$15 million facility which, unlike a regular blood bank, will collect and store blood from the umbilical cords of newborn babies.
...

Doctors hope 90 percent of mothers will agree to donate their umbilical cords.

As an extra incentive, if a donor later develops a medical condition which requires a cord blood transplant, she gets priority -- not just for her own cord blood but for any stored blood.

And it is free.

Other transplant patients have to pay S$26,000 or about US$15,000 for every unit of cord blood.

This is to cover the processing, screening and storage of the blood.
...

The bank is expected to be up and running by the end of the year, either in KKH, SGH, or at the Biopolis.

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Singapore ink stem cell deal with US

A Singapore stem cell company has clinched a 1.7-million-U.S.-dollar contract from the U.S. Defence Department for a two-year vaccine-screening programme, news media said on Monday.

Cordlife's Boston-based subsidiary, Cytomatric, will produce "T- cells" from adult stem cells outside the human body for the first time, the Straits Times said.

Those produced by Cytomatrix function like those in the human immune system, and will be used to screen prototype vaccines.

"This is the first time such an approach is being used anywhere in the world", Cytomatrix President Mark Pykett was quoted as saying.

The screening process will cut both cost and time because it allows researchers to determine the effectiveness of the vaccines on the body's immune system without directly exposing humans to the test, Cordlife said.

The technique is also likely to reduce or even eliminate the need to test the vaccines on animals in the early stages of development.

[Cyto]

New stem-cell gel advances spinal injury research

In a study that could lead to new treatments for spinal cord injury, Northwestern University researchers have coaxed neural stem cells to grow in a specially engineered gel that could be injected directly to a site of spinal damage.

Central to the effort is a self-assembling gel developed by Northwestern nanotechnology researcher Samuel Stupp. The material is a soapy-looking solution that, when it comes in contact with living cells, becomes a gel with tiny fibers that can guide the growth of neurons or other types of tissue.

"Complex diseases need multidisciplinary approaches," said Snyder, director of the stem-cell program at the Burnham Institute in California.

[Cyto]

Stem Cells Curb Osteoarthritis in Goats

Injections of stem cell appear to help regenerate joint tissues and retard cartilage damage in goats with a form of osteoarthritis.

As Dr. Frank P. Barry told Reuters Health, "This study suggests that there may be a therapeutic benefit associated with local delivery of ... stem cells following traumatic injury to the knee. The longer term effect of this may be a reduction or delay in the progression to osteoarthritis."

To investigate, the researchers obtained adult stem cells from the bone marrow of goats. They then surgically induced osteoarthritis in one knee joint of the animals.

After 6 weeks, the researchers then injected 10 million stem cells obtained from each animal into its injured knee. Control animals received a sham injection.

In cell-treated joints, there was a marked regeneration of joint tissues, and implanted cells were detected in the new tissue. In addition, degeneration of cartilage and remodeling of the bone were reduced.

[chubtoad]

Skin Regeneration Not Isolated To Epidermal Stem Cells

The outermost layer of the skin – the epidermis – is a rapidly renewing tissue and relies on the regenerative capacity of keratinocytes. Skin grafts using human cultured epidermal cells have been successful in treating patients with severe skin wounds. The notion that the ability to regenerate functional epidermal tissue is an exclusive property of epidermal stem cells is a general assumption in the stem cell biology field. In the February 2 issue of the Journal of Clinical Investigation, Pritinder Kaur and colleagues at the Peter MacCallum Cancer Centre, Australia, demonstrate that both epidermal stems cells and their early, differentiated progeny contribute to rapid epidermal regeneration.

[Cyto]

Matrix revolutions in 3D(In depth article) (To access: Login: XxDoubleHelixX Pass: postman)

Three-dimensional bioactive scaffolds hold great promise as substrates for generating tissue from stem cells in vitro and for promoting tissue regeneration in vivo. As reported in Science, Silva and colleagues have developed a remarkable new nanofibre matrix that assembles spontaneously when it comes into contact with cells, and can be engineered to promote neuronal differentiation.

The authors constructed a molecule called IKVAV-PA, which included the five-amino-acid motif IKVAV (isoleucine–lysine–valine–alanine–valine). This motif occurs in the extracellular matrix component laminin, and it has been shown to induce and direct the growth of neurites. The IKVAV-PA molecules carried a net negative charge, and mutual repulsion prevented them from aggregating in solution at pH 7.4. However, when they were exposed to positive ions — for example, in living tissue — they formed nanofibres and assembled into a gel-like matrix.

The authors added mouse neural progenitor cells to a solution of IKVAV-PA, prompting the formation of a matrix that encapsulated the cells. The resulting scaffold had a high water content, which allowed efficient diffusion of nutrients. A high proportion of the progenitors differentiated rapidly into neurons, as indicated by the expression of specific marker genes and neurite outgrowth. By contrast, there was little evidence of astrocytic differentiation. A control molecule — EQS-PA — in which the laminin motif was replaced by the non-physiological sequence glutamic acid–glutamine–serine (EQS), was also capable of self-assembly, but failed to induce neuronal differentiation.

Interestingly, the IKVAV-PA nanofibres were also effective at promoting neuronal differentiation when they were presented to neural progenitors as a two-dimensional substrate on a culture dish. The authors proposed that the key to the success of the matrix is the high density of IKVAV epitope that is presented to the cells, rather than the three-dimensional conformation. A soluble IKVAV peptide added to an EQS-PA matrix was far less efficient at stimulating neuronal differentiation than the IKVAV-PA scaffold, indicating that the epitope needs to be integrated into the nanofibres to be appropriately presented.

Silva et al. found that the matrix could also be induced to assemble if it was injected into tissue, raising the tantalizing possibility that it could be used to stimulate the regeneration of injured nerves in vivo. As the matrix assembles on contact with tissue, it could be injected as a fluid at the injury site, which would be far less invasive than implanting a pre-formed scaffold. Also, because the IKVAV-PA scaffold seems to suppress astrocytic differentiation, it is unlikely to exacerbate the injury by inducing glial scar formation. Further investigations should uncover the full potential of this intriguing material.

[Cyto]

Stem cell research backers push for funding measure

SAN FRANCISCO - A coalition of wealthy patient advocates, eminent scientists and Hollywood executives have launched a well-funded campaign to make California a hub for human embryonic stem cell research, even as tepid federal support slows such efforts elsewhere.

The group is trying to qualify a $3 billion bond proposition for the November ballot that would make California the first state in the nation -- and the largest U.S. public entity -- to fund such research.

The proposal also would fund laboratory cloning projects intended to create stem cells for regenerative and therapeutic medicine while specifically shunning cloning programs aimed at creating babies.

If passed, the measure would make $295 million available annually for 10 years, far exceeding the $10.7 million awarded by the federal government in 2002.

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President's advice to doctors (India)

President A P J Abdul Kalam said newer knowledge emerging out of research on stem cells from abroad and in the country has to be taken note of and studied. In fact, regenerative medicine is fast getting established as a complete branch of medical science. He asked the Cancer Institute to carry out stem cell research for promoting enhanced probability of success in cancer treatment.

[immortalitysystems.com]

Does somebody know how to contact the group that is trying to qualify the bond measure to promote human embryonic stem cell research for the california November ballot?

[Cyto]

Since this group is very new I think you would need a middle party to answer your questions. Such institutes as the Christopher Reeve Paralysis Foundation and the American Diabetes Association support this. The Christopher Reeve Paralysis Foundation American Diabetes Association

Another note...
After a double-take I found that the anti-abortion interview is done with the Discovery Inst. And for those of us who don't know what this Inst. really stands for I will tell you:
It is established to try and discredit evolution overall, preach the intelligent design faith, and thus sneak religion fetters into the human core known as science. They are morons, they are dangerous morons.

"The technology is extremely questionable, morally and practically," said Wesley Smith, a fellow at the Discovery Institute think tank in Seattle. "Treating human life, however nascent, as a product is incredibly inhumane."

[Cyto]

Database on blood and marrow stem cell transplants now available online

The MHC database

The National Institute of Allergy and Infectious Diseases (NIAID), the National Library of Medicine (NLM) and the National Center for Biotechnology Information (NCBI), components of the National Institutes of Health (NIH), today launched the first public database of results from clinical blood and marrow stem cell transplants involving unrelated donors.

With the availability of this new database, researchers can generate and test hypotheses on the role of donor matching in blood and marrow stem cell transplants. The database also provides survival rates of people who received cell grafts, helping doctors and their patients evaluate the potential risks and benefits of transplantation in treating disorders such as leukemia.

"This important new resource will make it easier for physicians to predict outcomes of blood and marrow stem cell transplants and to tailor therapies to the specific needs of their patients," says Anthony S. Fauci, M.D., director of NIAID.

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Stem cell bank opens

Shanghai's first stem cell bank opened recently here, spurred by growing interest in the potential life saving benefits for children of donors.

To help residents learn more about stem cells and how to store umbilical cord blood, the "life bank" has also set up a hotline.

"The line is quite busy and we get many queries everyday. People ask various questions about the blood reserve," said Lu Qiong, a consultant of the "life bank".

Storing the blood comes at a cost. Donors have to pay 5,800 yuan (US$698.80) for the first year of storage and an annual charge of 600 yuan (US$72.00) for the following years' storage.

Normally, the blood can be stored for 15 to 20 years, Lu said.

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Neurologists create a font of human nerve cells

The researchers, led by neurologist Steven Goldman, M.D., Ph.D., of the University of Rochester Medical Center, created the unique cells by introducing a gene called telomerase, which is responsible for the ability of stem cells to live indefinitely, into more specialized "progenitor" cells. In normal development, these progenitor cells give rise to very specific types of spinal neurons, but they do so for only short periods of time, because they lack the ability to continuously divide. With the newly added telomerase gene, the spinal progenitor cells were able to continuously divide while still producing only specific types of neurons. The outcome was a line of immortal progenitor cells, capable of churning out human spinal neurons indefinitely.

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Govt. to Provide Over W152 Bil. for Research on Stem Cell Application (Korea)

The Ministry of Science and Technology plans to provide a total of W152 billion (US$130 million) by 2012 for research on application of stem cells. The decision came following the latest medical breakthrough by Professors Hwang Woo-suk and Moon Shin-yong of Seoul National University who for the first time in the world succeeded in extracting embryonic stem cells from cloned human embryos.

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The cover shows a reconstruction of the skull and brain, based on computed tomography, indicating regions of the subventricular zone where these stem cells are found.

Unique astrocyte ribbon in adult human brain contains neural stem cells but lacks chain migration

The subventricular zone (SVZ) is a principal source of adult neural stem cells in the rodent brain, generating thousands of olfactory bulb neurons every day. If the adult human brain contains a comparable germinal region, this could have considerable implications for future neuroregenerative therapy. Stem cells have been isolated from the human brain, but the identity, organization and function of adult neural stem cells in the human SVZ are unknown. Here we describe a ribbon of SVZ astrocytes lining the lateral ventricles of the adult human brain that proliferate in vivo and behave as multipotent progenitor cells in vitro. This astrocytic ribbon has not been observed in other vertebrates studied. Unexpectedly, we find no evidence of chains of migrating neuroblasts in the SVZ or in the pathway to the olfactory bulb. Our work identifies SVZ astrocytes as neural stem cells in a niche of unique organization in the adult human brain.

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Pro-lifers angry at $6M proposal for stem cell research (Funding through the tax payer)

"What we're talking about here is farming humans through birth for destructive research in the state of New Jersey. If this isn't repulsive, I don't know what is," said Marie Tasy, legislative affairs director for New Jersey Right to Life.

"It is bad enough Gov. McGreevey sold out humanity and ignored the will of the people to do the bidding of the biotech industry," she said, referring to last year's passage of a bill in support of stem cell research.

"He is now trying to force this immoral research down the throats of taxpayers," Tasy added.

"What we view as the ethical issue, the matter of conscience, is having to look hundreds of thousands of families in the eye and telling them we are not doing everything we can," said Micah Rasmussen, a McGreevey spokesman.

David Beck, president of the Camden-based Coriell Institute, conducts research on the less-controversial adult stem cells. Although his facility does not conduct experiments on the embryonic cells, he believes the research to be necessary.

"The promise is just too important here to pass up," said Beck. He explained that both strains of research are needed to ensure continuity, especially if one strain proves unsuccessful.

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The Transcriptome Profile of Human Embryonic Stem Cells as Defined by SAGE
Stem Cells 2004;22:51-64 www.StemCells.com

Human embryonic stem (ES) cell lines that have the ability to self-renew and differentiate into specific cell types have been established. The molecular mechanisms for self-renewal and differentiation, however, are poorly understood. We determined the transcriptome profiles for two proprietary human ES cell lines (HES3 and HES4, ES Cell International), and compared them with murine ES cells and other human tissues. Human and mouse ES cells appear to share a number of expressed gene products although there are numerous notable differences, including an inactive leukemia inhibitory factor pathway and the high preponderance of several important genes like POU5F1 and SOX2 in human ES cells. We have established a list of genes comprised of known ES-specific genes and new candidates that can serve as markers for human ES cells and may also contribute to the "stemness" phenotype. Of particular interest was the downregulation of DNMT3B and LIN28 mRNAs during ES cell differentiation. The overlapping similarities and differences in gene expression profiles of human and mouse ES cells provide a foundation for a detailed and concerted dissection of the molecular and cellular mechanisms governing their pluripotency, directed differentiation into specific cell types, and extended ability for self-renewal.

Survival and Long Distance Migration of Brain-Derived Precursor Cells Transplanted to Adult Rat Retina
Stem Cells 2004;22:51-64 www.StemCells.com

Neural precursor cells transplanted to adult retina can integrate into the host. This is especially true when the neural precursor rat cell line RN33B is used. This cell line carries the reporter genes LacZ and green fluorescent protein (GFP). In grafted rat eyes, RN33B cells are localized from one eccentricity to the other of the host retina. In the present study, whole-mounted retinas were analyzed to obtain a more appropriate evaluation of the amount of transgene-expressing cells and the migratory capacity of these cells 3 and 8 weeks post-transplantation. Quantification was made of the number of ß-galactosidase- and GFP-expressing cells with a semiautomatized stereological cell counting system. With the same system, delineation of the distribution area of the grafted cells was also performed. At 3 weeks, 68% of the grafted eyes contained marker-expressing cells, whereas at 8 weeks only 35% of the eyes contained such cells. Counting of marker-expressing cells demonstrated a lower number of transgene-expressing cells at 3 weeks compared with 8 weeks post-transplantation. The distribution pattern of marker gene-expressing cells revealed cells occupying up to 21% at 3 weeks and up to 68% at 8 weeks of the entire host retina post-grafting. The precursor cells survived well in the adult retina although the most striking feature of the RN33B cell line was its extraordinary migratory capacity. This capability could be useful if precursor cells are used to deliver necessary genes or gene products that need to be distributed over a large diseased area.