Thursday, November 22, 2012

Rejuvenating Aged Human Cells w/ Cytokine Growth Factors

A recent collaboration between researchers in Toronto and researchers in Harbin, China, has uncovered the ability to rejuvenate adult mesenchymal stem cells to be used on scaffolds as a healthy replacement for damaged heart tissue -- in heart failure and after massive myocardial infarction.
In the present study, the researchers report a new method to repair damaged hearts that could occur from heart attacks.

Specifically they studied the ability to rejuvenate adult bone marrow cells and embed them into a biodegradable patch which could then be implanted into damaged hearts.

To perform the study, the researchers first created a biodegradable collagen scaffold upon which they coated two growth factors known to promote cell growth, VEGF and bFGF.

Next they seeded human mesenchymal stromal cells from the bone marrow of middle aged (50) and old aged (75 ) donors onto the scaffold.

The scaffolds were then grown in culture and examined for cell growth and function in rats with damaged hearts. They grew patches both with and without the growth factors.

They found that old cells didn’t grow as well into the patches than young cells and the patches were not as effective when implanted in rats.

However adding the rejuvenative cytokines caused the old cells to rejuvenate. After treatment these cells grew in better and the patches performed better.

The researchers determined that the old cells had a different RNA pattern after exposure to the growth agent. In particular a gene called p16 which is expressed in all aged senescent cells was markedly reduced. _Extremelongevity.net
This new ability to transform the gene expression of old stem cells to more closely match the gene expression of young stem cells, offers a general promise of rejuvenation to all aging cells -- once scientists discover safer ways of inducing such revitalising transformations.

Restoration of cardiac function was possible with a cytokine-enhanced, tissue-engineered patch that rejuvenated aged cells. Covalent immobilization of 2 proangiogenic cytokines, VEGF and bFGF, onto a collagen scaffold enhanced cell proliferation in vitro and prolonged cell survival and improved angiogenesis to restore ventricular morphology and function in vivo. Of note, the improvement was most obvious with patches seeded with cells from old donors. This novel cytokine-conjugated, sustained-release system provides a practical and promising platform for cardiac repair in elderly survivors of an extensive MI, an important advance in an increasingly aging society _Jn. Am. Coll. Cardiology (PDF) via extremelongevity.net

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Tuesday, May 15, 2012

Intravenous Stem Cells: Where Do They Go? What Do They Do?

We usually think of stem cell therapy in terms of replacing damaged cells or tissues with stem cells, which can differentiate and become the type of cell or tissue which is being replaced. But there is more to it than that, particularly in the case of intravenous stem cell infusion.
Researchers have tracked the migration of stem cells administered intravenously following an injury. At first the majority of the cells lodge within the lung, where they appear to interact with pulmonary macrophages altering the type of cell signaling molecules those macrophages release into the blood. Next the stem cells migrate to the organs of the reticuloendothelial system which includes the spleen. Surprisingly, less than 3% of infused stem cells migrate into brain tissue. So the immunomodulatory effect does not require the majority of infused stem cells to interact directly with injured brain tissue. _SciAm
It turns out that much of the beneficial effect from the intravenous infusion of stem cells comes from their effect on the immune system. IV infused stem cells apparently shift the immune system's response to injury and rejuvenation, creating a more favourable environment for healing and regeneration.

This allows the few stems cells which make it all the way to the damaged tissue, to promote regeneration locally without a harmful immune response.
Immunomodulatory stem cell studies attempt to adjust the immune response in a way that minimizes the damage associated with the initial injury, and then allows the individual’s native repair machinery to function optimally.

With even mild injury, the immune system is activated. Macrophages are a type of immune cell which participate in the post-injury immune response. With “classic” macrophage activation, the immune response is aggressively induced. Classically activated macrophages are described as having an “M1” phenotype. In the nervous system, the M1 immune response can increase the severity of an injury. Alternatively activated or “M2” macrophages, are associated with a less destructive pattern of immune system activation. This alternate/M2 response results in less immune mediated post-injury damage, as well as the possible disinhibition of native nervous system repair.

Following traumatic brain injury (TBI) children experience a loss of 12-15% of their brain tissue in the 12 months following their injury (Levin). In a study where we treated TBI children with their own bone marrow stem cells, there was minimal post injury brain volume loss in the year after TBI (Cox). In animal models of TBI, animals that experienced injury were found to have M1 macrophages throughout their injured brain tissue.

Animals treated with stem cells after TBI were found to have M2 macrophages in their brain parenchyma. Interestingly, if an animal’s spleen was removed before stem cell infusion, the benefit of the stem cell treatment was eliminated. Somehow stem cell infusion causes a change in the pattern of macrophage activation from M1 to M2, which results in a less aggressive immune response and less post-injury brain tissue death. This effect requires an intact spleen. _SciAm
So you see that in an optimal response to stem cell infusion following an injury, the patient will experience both immunomodulatory effect and a regenerative effect from the IV stem cell infusion.

When the stem cells being infused are of a broad-spectrum nature -- such as cord blood, embryonic stem cells, or pluripotent adult stem cells -- the door is wide open for other effects beyond the immunomodulatory and the regenerative (replacement) effects. It should be clear that other rejuvenative effects are also possible from broad spectrum stem cell infusion. It will simply require a good deal of research and consideration before most of those effects can be discovered and decoded for optimal therapies in the future.

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Monday, May 07, 2012

Mastering Cell Signaling: A Worthy Goal

Cells make decisions in fluctuating environments using inherently noisy biochemical mechanisms. Such effects create considerable, unpredictable variation – known as ‘stochasticity’– both over time and between genetically identical cells. To understand how cells exploit and control these biochemical fluctuations, scientists must identify the sources of stochasticity, quantify their effects, and distinguish variation that carries information about the biological environment from confounding noise.

In their PNAS paper, Dr Bowsher and Professor Swain show how to decompose the fluctuations of biochemical networks into multiple components and how to design experimental ‘reporters’ to measure these components in living cells.

The paper, which describes the application of this approach to yeast cells, shows that the majority of cellular variation may be informational in origin and due to fluctuations in the cellular environment. The results pave the way to a better understanding of the dynamics of signal processing and decision-making by cells. _SD
Cell Signaling Network, Preliminary Sketch

We begin to comprehend the potential power of cell signaling mastery, when we observe research breakthroughs such as the following:
In laboratory experiments with mouse cells, the researchers found that a specific protein that regulates cell aging also controls a process that causes blood-making stem cells to age. Using drugs to inhibit the action of this protein (called Cdc42) reversed aging of the hematopoietic stem cells and restored their function to a level similar to that of younger stem cells.

It had been [previously] believed that the aging of hematopoietic stem cells was locked in by nature and could not be reversed by using drugs, according to a hospital news release.

...The study by scientists at Cincinnati Children's Hospital Medical Center and Ulm University Medicine in Germany appeared online May 3 in the journal Cell Stem Cell. _USN
Turning old hematopoietic stem cells into young hematopoietic stem cells is nothing to sneeze at. And it is only a slight foretaste of what is becoming possible, as we better understand cell signaling networks and the signaling involved in gene expression.

One of the more exciting near-to-intermediate term possibility arising from the coming mastery of cell signaling, is the ability to reverse neurodegenerative diseases which involve abnormal protein folding. Diseases such as Alzheimer's, Huntington's, Parkinson's, and "mad cow disease," for example, involve abnormal proteins leading to cell destruction and loss of neural function.
Researchers at the University of Leicester uncovered how the build-up of proteins in mice with prion disease resulted in brain cells dying.

They showed that as misfolded protein levels rise in the brain, cells respond by trying to shut down the production of all new proteins.

...The team at the Medical Research Council laboratory in Leicester then tried to manipulate the switch which turned the protein factory off. When they prevented cells from shutting down, they prevented the brain dying. The mice then lived significantly longer.

Each neuro-degenerative disease results in a unique set of misfolded proteins being produced, which are then thought to lead to brain cells dying.

Prof Giovanna Mallucci told the BBC: "The novelty here is we're just targeting the protein shut-down, we're ignoring the prion protein and that's what makes it potentially relevant across the board."

The idea, which has not yet been tested, is that if preventing the shut down protects the brain in prion disease - it might work in all diseases that have misfolded proteins.

Prof Mallucci added: "What it gives you is an appealing concept that one pathway and therefore one treatment could have benefits across a range of disorders. _BBC
Nature article

Complex cell signaling is also involved in the control of gene expression, including critically important DNA repair, and control of telomere length in cells -- which controls the number of cell doublings allowed.

If you click on the image above, you can view an enlarged version of a portion of a cell signaling network. Such complexity explains the need for high powered computational backup in the attempt to decode these networks, as a prelude to their mastery.

Cellular processes take place very quickly, and in a closely controlled and balanced chemical milieu. If we are to learn to intervene on the level of the cell in a beneficial way, we must proceed with care. But we definitely aim to proceed.

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Thursday, January 26, 2012

Important New Insights into Alzheimer's Disease from Cultured Adult Induced Stem Cells from Alzheimer's Patients


When you take skin cells from an Alzheimer's patient, and turn them into neurons in culture, you can study these "Alzheimer's neurons" in detail in the lab. This ability to work with cultured human Alzheimer neurons from induced stem cells, on a day to day basis, will give scientists an intimate familiarity with the genetic and biochemical differences which lead to the pathological changes in the disease. And none too soon, because as western societies grow older, Alzheimer's is threatening to bankrupt their social medicine services.
The feat, published in the January 25 online edition of the journal Nature, represents a new and much-needed method for studying the causes of AD, a progressive dementia that afflicts approximately 5.4 million Americans. More importantly, the living cells provide an unprecedented tool for developing and testing drugs to treat the disorder.

“We’re dealing with the human brain. You can’t just do a biopsy on living patients,” said Goldstein. “Instead, researchers have had to work around, mimicking some aspects of the disease in non-neuronal human cells or using limited animal models. Neither approach is really satisfactory.”

Goldstein and colleagues extracted primary fibroblasts from skin tissues taken from two patients with familial AD (a rare, early-onset form of the disease associated with a genetic predisposition), two patients with sporadic AD (the common form whose cause is not known) and two persons with no known neurological problems. They reprogrammed the fibroblasts into induced pluripotent stem cells (iPSCs) that then differentiated into working neurons.

The iPSC-derived neurons from the Alzheimer’s patients exhibited normal electrophysiological activity, formed functional synaptic contacts and, critically, displayed tell-tale indicators of AD. Specifically, they possessed higher-than-normal levels of proteins associated with the disorder.

With the in vitro Alzheimer’s neurons, scientists can more deeply investigate how AD begins and chart the biochemical processes that eventually destroy brain cells associated with elemental cognitive functions like memory. Currently, AD research depends heavily upon studies of post-mortem tissues, long after the damage has been done.

“The differences between a healthy neuron and an Alzheimer’s neuron are subtle,” said Goldstein. “It basically comes down to low-level mischief accumulating over a very long time, with catastrophic results.”

The researchers have already produced some surprising findings. “In this work, we show that one of the early changes in Alzheimer’s neurons thought to be an initiating event in the course of the disease turns out not to be that significant,” Goldstein said, adding that they discovered a different early event plays a bigger role.

The scientists also found that neurons derived from one of the two patients with sporadic AD exhibited biochemical changes possibly linked to the disease. The discovery suggests that there may be sub-categories of the disorder and that, in the future, potential therapies might be targeted to specific groups of AD patients.

Though just a beginning, Goldstein emphasized the iPSC-derived Alzheimer’s neurons present a huge opportunity in a desperate fight. _UCSD

This research is geared specifically toward Alzheimer's disease research, since Alzheimer's patients are the donours of the original cells being used. But the same approach can be used to culture a wide range of induced cell types, from patients with a wide range of disease types. In other words, this is just the beginning of a beautiful approach to bringing the full dynamics of human diseases into the laboratory for thorough study.

There is no way of predicting what possibilities may arise from this research over the long run.

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Monday, January 16, 2012

3 Dimensional Bio-Cell Printing: Future Tissue & Organ Replacements

An optimized 3D inkjet printing process is demonstrated for structuring alginate into a tissue-like microvasculature capable of supporting physiological flow rates. Optimizing the reaction at the single-droplet level enables wet hydrogel droplets to be stacked, thus overcoming their natural tendancy to spread and coalesce. Live cells can be patterned using this process and it can be extended to a range of other hydrogels. _Advanced Materials
The dream is to be able to rapidly grow replacement tissues and organs, to allow for easy autologous replacement for a wide range of clinical reasons and circumstances -- including life extension regenerative treatments.
...Thus, it would take just under 2 hours to print a 1 cm thick tissue precursor graft and just over 5 h 30 to print a 3 cm thick kidney precursor. _Advanced Materials PDF
Swiss scientists are using a special inkjet printer to assemble three dimensional living constructs that resemble living tissues. They are still in the early stages of the research, but are achieving some interesting results.
They are working on a technique that should eventually allow them to “print” living constructs resembling human tissues in which cells can develop and interact in a coordinated and physiological manner. Their research results have recently been published in the scientific journal Advanced Materials.

“We have not yet created tissue, strictly speaking,” explains Professor Jürgen Brügger, head of EPFL’s Microsystems 1 Laboratory. “At this stage, we have essentially studied a way in which to structure biological materials in three dimensions; this research will improve cell culture and then will eventually be used as a base for creating tissues.”

...To make up a coherent whole, the cells need an environment that provides the right kinds of signals that induce very specific behavior in each of the cells – proliferation, migration, differentiation or death. In natural tissues, these signals come from molecules that make up a complex extracellular matrix (ECM). By studying the connections and communications taking place between cells and between cells and ECM molecules, the scientists were able to reconstruct this matrix and thus create a new kind of biological ink.

On a technical level, the researchers from EPFL’s two Microsystems Laboratories – under the leadership of professors Jürgen Brugger and Philippe Renaud – focused on developing a gel that could be used as a base from which the tissue could be constructed, as well as a strategy for printing droplets.

...Even though it will still be quite some time before tissue can be constructed, this technology could lead to very promising applications on the medium term. “ An exiting avenue would be to develop 3D constructs that function like human tissues and could be used as models for testing new drugs,” says Lutolf. “This is not only very interesting in a biological sense, but could also reduce the need for animal testing.” _Physorg

Learning to create life-like 3 dimensional cell cultures for research, and learning to create 3-D lab-made living tissues for replacement, are not quite the same things. But the two lines of research are likely to borrow from and contribute to each other, extensively.

This research used fibroblasts. Future research is likely to use a variety of stem cells and other precursor cells for various cell types.
Non-fluorescent NIH 3T3 fibroblasts were used in this printing as to be compatible with the fluorescent Live-Dead assay. The cells were suspended in culture medium supplemented with 0.8% wt. non-fluorescent alginate at a concentration of 1x10 6 mL -1 . Cells were inkjet printed onto 2% wt. gelatin substrates prepared with 0.9% wt. NaCl and 10 mM CaCl2, prepared in a 96-well plate. All cells were incubated for 4h before Live-Dead staining. _Advanced Materials

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Tuesday, January 03, 2012

Young Stem Cells In Old Mice Increased Lifespan

A special breed of mice lived up to three times longer than normal after University of Pittsburgh researchers injected them with stem cells from younger, healthy mice, according to a study being published today in the journal Nature Communications.

Working with mice that are bred to die prematurely, Pitt researchers led by Johnny Huard and Laura Niedernhofer dramatically increased the animals' lifespans by injecting them in the abdomen with young animals' muscle stem cells. _Post-Gazette

Keep in mind that this research was done in a special breed of mouse that is programmed to have a shorter lifespan. Additional research will be required to determine if normal ageing mice can benefit from similar treatment.
"We wanted to see if we could rescue these rapidly aging animals, so we injected stem/progenitor cells from young, healthy mice into the abdomens of 17-day-old progeria mice," Dr. Huard said. "Typically the progeria mice die at around 21 to 28 days of age, but the treated animals lived far longer – some even lived beyond 66 days. They also were in better general health."

As the progeria mice age, they lose muscle mass in their hind limbs, hunch over, tremble, and move slowly and awkwardly. Affected mice that got a shot of stem cells just before showing the first signs of aging were more like normal mice, and they grew almost as large. Closer examination showed new blood vessel growth in the brain and muscle, even though the stem/progenitor cells weren't detected in those tissues.

In fact, the cells didn't migrate to any particular tissue after injection into the abdomen.
"This leads us to think that healthy cells secrete factors to create an environment that help correct the dysfunction present in the native stem cell population and aged tissue," Dr. Niedernhofer said. "In a culture dish experiment, we put young stem cells close to, but not touching, progeria stem cells, and the unhealthy cells functionally improved." _MedXpress
Stem cells can conceivably be used for many purposes, in the treatment of ageing. In the case of the above research, the stem cells apparently secreted some type of hormonal growth factor which was lacking in the progeria mice.

But in future, more sophisticated uses of stem cells to treat ageing, stem cells will be used for tissue replacement, organ regeneration and replacement, humoral factor replacement, and probably other uses not yet discovered.

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Monday, November 21, 2011

Proof of Concept for Rejuvenating Effect of Stem Cells: Pregnancy

Stem cell research has been controversial for decades. But we are beginning to learn that stem cell rejuvenation therapy experiments have been taking place for as long as humans have walked the Earth.

In earlier articles, we explained how pregnancy can make a woman younger due to the transfer of certain molecules -- hormones, growth factors etc -- from the fetus to the mother. In another article we learned that pregnancy can help make women's brains work better. Now we learn that pregnant women's bodies can be regenerated via embryonic stem cell rejuvenation treatments from the fetus.

These findings come from research in mice done at Mount Sinai School of Medicine in New York:
Mouse fetuses will give up stem cells to repair their mother's heart. The discovery could explain why half the women who develop heart weakness during or just after pregnancy recover spontaneously.

Hina Chaudhry of the Mount Sinai School of Medicine in New York City mated normal female mice with males genetically engineered to produce a green-fluorescing protein in all their body cells. Half the resulting fetuses also produced the protein, making it easy to spot any fetal tissue in the mother.

Chaudhry's team inflicted a heart attack on the pregnant mice and killed them two weeks later to take a look at their hearts. They found some fluorescent cells in the mothers' damaged heart tissue, where they had accelerated repair by changing into new heart cells, including beating cardiomyocytes and blood vessel cells.

Chaudhry says that the phenomenon is an evolutionary mechanism: the fetus promotes its own survival by protecting its mother's heart. Because the cells are easy to obtain from the placenta and unlikely to cause immunological reactions, they could provide a new and potentially limitless source of stem cells for repairing damaged hearts.

"The study is the first to show conclusively that fetal cells contained in the placenta assist in cardiac tissue repair," says Jakub Tolar, director of stem-cell therapies at the University of Minnesota in Minneapolis. _NewScientist
All the debate that has gone on over embryonic stem cell treatments, and we discover that it has been going on in mammals from the beginning.

Now it is a matter of learning how to maximise the positive effects of pregnancy, and to compensate for the potential negative effects.

Of course, in the long run, artificial wombs will relieve most women of the burden of gestation. But for those stylishly retro women who will wish to carry their own -- the advantages continue to build.

Above cross-posted from Al Fin, You Sexy Thing!

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Monday, November 14, 2011

Stem Cell Research Starting to Pay Off

A total of 23 patients took part in the ''Scipio'' trial, all of whom had suffered heart failure due to a previous heart attack. Sixteen were assigned to the stem cell therapy while the other seven received standard care.

...The ground-breaking new treatment involved extracting cardiac stem cells (CSCs) - self-renewing cells that rebuild hearts and arteries - from patients during bypass surgery.
The cells were purified and grown in the laboratory before being injected back into damaged regions of the patients' hearts four months later.

A million CSCs were infused into each patient via a balloon catheter, an expandable device used to open up arteries.

Heart pumping efficiency is assessed by measuring the fraction of blood expelled or ''ejected'' from the left ventricle with each beat.

At the start of the study, the patients had an average left ventricular ejection fraction (LVEF) of 40% or lower. Normal LVEF is 50% or higher.

Over a period of four months patients who underwent the treatment saw an 8.5% improvement in LVEF. After one year, this increased to 12.3%. LVEF did not change in the seven ''control'' patients who did not receive the therapy.

The findings were published today in an online edition of The Lancet medical journal. They were also presented at the American Heart Association's Scientific Sessions meeting in Orlando, Florida.

Magnetic Resonance Imaging (MRI) scans conducted on a number of patients showed that scarring in their hearts had been reduced.

The small Phase I study was primarily designed to assess safety rather than effectiveness. _Telegraph
As noted, the study was a "Phase I" clinical study meant to determine the safety of the treatment. In later, Phase II studies, efficacy will be looked at more closely. The results from this trial are quite encouraging -- modest but significant -- allowing a greater range of activity for the treatment group, post trial.

More from Genetic Engineering News:
Stage A of the ongoing open-label Phase I SCIPIO (Stem Cell Infusion in Patients with Ischemic cardiOmyopathy) study, by investigators at the University of Louisville and Brigham and Women’s Hospital, is evaluating CSC transplantation in patients with severe heart failure secondary to ischemic cardiomyopathy. The target population includes patients who underwent coronary artery bypass grafting (CABG), had LV ejection fraction (EF) of less than or equal to 40%, and a previous myocardial infarction.

Treated patients were administered with about a million autologous CSCs by intracoronary infusion, at a mean of 113 days after CABG. To generate the cardiac stem cells, tissue from the right atrial appendage was harvested from the patients at the time of CABG, and CSCs were isolated and expanded at the Brigham and Women’s Hospital.

...The trial has been led by Roberto Bolli, M.D., at the University of Louisville and Piero Anversa, Ph.D., at Brigham and Women's Hospital/Harvard Medical School in Boston. "The results are striking," Dr. Bolli states. "While we do not yet know why the improvement occurs, we have no doubt now that ejection fraction increased and scarring decreased. If these results hold up in future studies, I believe this could be the biggest revolution in cardiovascular medicine in my lifetime."

The published paper in The Lancet is titled "Cardiac stem cells in patients with ischaemic cardiomyopathy (SCIPIO): initial results of a randomised Phase I trial.” _GenEngNews
Heart muscle is relatively uncomplicated, as far as vital organs go, so it is not a great surprise that such a simple stem cell replacement therapy might work. Liver and pancreas may be similarly amenable to simple stem cell infusion. But other organs will require more clever designs for creating replacement tissue from stem cells and scaffolding.

In terms of numbers of persons potentially affected by this therapy for heart failure, the number will easily go into the millions in North America alone. Optimal therapy may require multiple infusions over time, to allow the heart to assimilate the new cells. More will be known as the research progresses into further stages.

This is just the beginning.

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Thursday, September 15, 2011

IPS Stem Cells Are Looking More Promising for Regenerative Medicine

George Church is a professor of genetics at Harvard Medical School. He is becoming more and more deeply involved in the field of regenerative medicine, using induced pluripotent stem cells (IPS). Church was interviewed recently on how he sees the field of IPS regenerative medicine progressing.
A pioneer in developing DNA sequencing technologies, and in researching everything from epigenetics and microbiomics to synthetic biology, Church has co-founded or advises over 20 companies. He also has launched the Personalized Genome Project with a goal of sequencing the complete genomes of 100,000 volunteers.

When I asked Church what he was most excited about right now, he answered without hesitation: "I'm thinking a lot about using regeneration as the key to treatments and keeping people healthy."

TR: You mean regeneration using stem cells?

Church: Yes, induced pluripotent stem (IPS) cells (see, "Growing Heart Cells Just for You"). This is where I'm putting almost all of my chips these days, because it combines many of my interests--genomics, sequencing, epigenetics, synthetic biology, stem cells. I don't think people have fully appreciated how quickly adult stem cells and sequencing and synthetic biology have progressed. They have progressed by orders of magnitude since we got IPS. Before that, they basically weren't working.

Is this because IPS cells are relatively easy to create and to engineer?

You can use them to reprogram genomes--not sequence them, but to reprogram them genetically and epigenetically. In other words you make the minimum changes it takes to get them where you want them to be genetically and epigenetically and then you program the cells into tissues.

What do you mean?

Let's use stem cells in bone marrow as an example. They are easy to use and to get to work when you implant them in bone marrow. You might one day have three choices. You can have bone marrow from someone else that is matched to you, or that is from you, or bone marrow that is matched to you and comes to you, but is better than you. This better bone marrow might be [engineered to be] resistant to one virus, or to all viruses. It could have a bunch of alleles that you picked out of super centenarians, alleles that you have reason to believe are at least harmless and possibly helpful. So now you have choice, a patient who can take a good bone marrow that he might reject and you'll be on immunosuppressants your whole life. Or you might use your own, or your own that might fix the cancer, or your own enhanced bone marrow. And you will be able to do that for almost every stem cell population. Some of them are a little bit harder to replace, though.

Does IPS really work to accomplish this regeneration?

We have good evidence that you can create an entire mouse from IPS cells.

Has this been done?

This has been done. They have used IPS cells to grow a mouse, and they made IPS cells from that mouse. They're totipotent [able to make an entire organism], not merely pluripotent. We haven't done this for humans for obvious ethical reasons, but we will do it. As far as I know the mice have done fine.

But haven't there been some problems with mutations occurring with IPS-generated tissue?

We have a recent paper in Nature that shows that when you make human induced pluripotent stem cells you actually do get mutations in coding regions at a slightly elevated level. But I think this is temporary. We're going to use this information as an assay to make the process work better, to correct problems. You will be able to use this to improve the quality of gene therapy because that's been the problem with gene therapy the last ten years.

How far are we from testing that in humans?

Almost everything I've described has been done in rodents, so we're talking about years, not decades. It's shorter than the Human Genome Project [which took 13 years], not less expensive, but definitely shorter. _TechnologyReview
Scientists at the University of Toronto have recently made a breakthrough in the control of IPS cells' pluripotency:
Scientists have found a control switch that regulates stem cell “pluripotency,” the capacity of stem cells to develop into any type of cell in the human body. The discovery reveals that pluripotency is regulated by a single event in a process called alternative splicing.

Alternative splicing allows one gene to generate many different genetic messages and protein products. The researchers found that in genetic messages of a gene called FOXP1, the switch was active in embryonic stem cells but silent in “adult” cells—those that had become the specialized cells that comprise organs and perform functions.

“It opens the field to the fact that alternative splicing plays a really important role in stem cell pluripotency,” said Prof. Benjamin Blencowe, principal investigator on the study and a Professor in the University of Toronto’s Departments of Molecular Genetics and Banting and Best Department of Medical Research. “We’re beginning to see an entirely new landscape of regulation, which will be crucial to our understanding of how to produce more effective pluripotent stem cells for therapeutic and research applications.”

The findings were published in the current online edition of the scientific journal Cell. _Source
These are some fascinating developments, which will eventually lead to advanced therapies for diseases which are currently untreatable, such as cancers and end stage degenerative diseases of the heart, lungs, liver, kidneys, and brain.

The ability to grow replacement organs from stem cells is already being proven in animals. The ability to regenerate a badly degenerated organ in situ, using stem cells, is also being proven. According to George Church, stem cells are also the best method for making genetic improvements to organs and organisms.

BioHeart's clinical stem cell trials in Mexico

ThermoGenesis an early commercial entrant into the human stem cell regenerative medicine industry

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Sunday, June 26, 2011

New Findings in the Control of Stem Cell Differentiation

Nodal Activin Pathways Image Source

Researchers from the Genome Institute of Singapore have helped to untangle how stem cells might be controlled with a single signaling pathway -- the nodal activin pathway.
Morphogens are secreted signaling molecules that orchestrate the spatial distribution and sequence of cellular differentiation events throughout embryonic development. The specific cell types, their localization and order of induction from recipient stem cell populations are determined by the concentration gradient of morphogens diffusing from the source of secretion. Previous studies have proposed some of the models by which morphogen gradients are initiated, established and stabilized including the level of receptor occupancy, positive/negative feedback and feed forward mechanisms [1]–[3]. However, little is understood about the transcriptional mechanisms responding to variable receptor activation and how they permit pluripotent stem cells to interpret signaling levels and direct the appropriate differentiation programs during mammalian development....

Nodal and Activin are morphogens of the TGFbeta superfamily of signaling molecules that direct differential cell fate decisions in a dose- and distance-dependent manner. During early embryonic development the Nodal/Activin pathway is responsible for the specification of mesoderm, endoderm, node, and mesendoderm. In contradiction to this drive towards cellular differentiation, the pathway also plays important roles in the maintenance of self-renewal and pluripotency in embryonic and epiblast stem cells. The molecular basis behind stem cell interpretation of Nodal/Activin signaling gradients and the undertaking of disparate cell fate decisions remains poorly understood. Here, we show that any perturbation of endogenous signaling levels in mouse embryonic stem cells leads to their exit from self-renewal towards divergent differentiation programs. Increasing Nodal signals above basal levels by direct stimulation with Activin promotes differentiation towards the mesendodermal lineages while repression of signaling with the specific Nodal/Activin receptor inhibitor SB431542 induces trophectodermal differentiation. To address how quantitative Nodal/Activin signals are translated qualitatively into distinct cell fates decisions, we performed chromatin immunoprecipitation of phospho-Smad2, the primary downstream transcriptional factor of the Nodal/Activin pathway, followed by massively parallel sequencing, and show that phospho-Smad2 binds to and regulates distinct subsets of target genes in a dose-dependent manner. Crucially, Nodal/Activin signaling directly controls the Oct4 master regulator of pluripotency by graded phospho-Smad2 binding in the promoter region. Hence stem cells interpret and carry out differential Nodal/Activin signaling instructions via a corresponding gradient of Smad2 phosphorylation that selectively titrates self-renewal against alternative differentiation programs by direct regulation of distinct target gene subsets and Oct4 expression. _PLoS Genetics

This finding has profound implications for experimental approaches to guided stem cell differentiation and / or stem cell self renewal. The ability to control multiple distinct sets of genes by titrating the dose of signaling molecules is likely to prove a very powerful tool for geneticists, stem cell researchers, and bio-developmental scientists.

In other longevity news, a team of scientists from multiple universities has helped elucidate how cryoprotectant molecules protect proteins from freezing. Future research should enlarge the scope of study to discover optimal cryoprotectants for cells, tissues, organs -- and eventually for entire organisms.

It is quite possible that different types and levels of cryoprotectant will prove optimal for different organs and tissues, so that in order to viably freeze and thaw an entire organism -- say, a human being -- a complex process of multiple simultaneous organ infusion with several cryoprotectants would be necessary.

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Saturday, May 15, 2010

Stem Cells to Restore Your Hearing, Your Heart, Your Teeth

Stanford University researchers have developed a way to grow replacement "hair cells" for the inner ear, in mice. The hair cells are responsible for hearing, and the cumulative loss of hair cells over a lifetime result in permanent hearing loss. If humans could learn to regenerate the hair cells in the inner ear, hearing loss could be reversed without the need for electronic devices such as cochlear implants or hearing aids. Source via Brian Wang

Geron scientists have demonstrated the safety of GRNCM1 (cardiomyocites or stem cells) for replacing damaged heart tissue. This treatment, once approved, is likely to be used to treat chronic heart failure -- a significant cause of death and disability worldwide.
Source 1 (via Brian Wang), Source 2

Columbia University researchers are developing a method for growing replacement teeth "in place", inside the actual socket of the lost tooth. The method utilises stem cells to re-grow the tooth along with accompanying soft tissue support. This approach will do away with the need to use hardware implants, or to grow teeth outside the body in culture media.
Source via Brian Wang

The re-growth of body organs in place -- using the original tissue matrix as a scaffolding -- is a safer approach than re-growing organs outside the body, then surgically implanting them. Both approaches will probably become common, but in circumstances where in situ stem cell replacement is effective, most persons will likely opt for that approach.

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Friday, May 07, 2010

Stem Cells from Endometrial Tissue Reverse Parkinson's?

Scientists at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), have injected endometrial stem cells into the brains of mice with an induced form of Parkinson's Disease. The injected stem cells began producing dopamine -- the neurotransmitter that is deficient in Parkinson's.
The finding raises the possibility that women with Parkinson's disease could serve as their own stem cell donors. Similarly, because endometrial stem cells are readily available and easy to collect, banks of endometrial stem cells could be stored for men and women with Parkinson's disease.

"These early results are encouraging," said Alan E. Guttmacher, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that funded the study. "Endometrial stem cells are widely available, easy to access and appear to take on the characteristics of nervous system tissue readily."

Parkinson's disease results from a loss of brain cells that produce the chemical messenger dopamine, which aids the transmission of brain signals that coordinate movement. This is the first time that researchers have successfully transplanted stem cells derived from the endometrium, or the lining of the uterus, into another kind of tissue (the brain) and shown that these cells can develop into cells with the properties of that tissue. The findings appear online in the Journal of Cellular and Molecular Medicine. _SD

An optimal form of brain regeneration would likely combine the use of exogenous growth factors and stem cells, along with the stimulation of endogenous stem cell and growth factor production. There is a lot to be learned about how the brain works normally, and what goes wrong in degenerative conditions, trauma, ischemia, and aging.

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Friday, April 09, 2010

Nano-Magnets Lead Stem Cells to Damaged Heart

A promising way of healing damaged heart tissue involves combining stem cells with nano-magnets.  The magnetised stem cells are then steered to the site of damage, using magnetic fields.
"Stem cell therapies show great promise as a treatment for heart injuries, but 24 hours after infusion, we found that less than 10 percent of the stem cells remain in the injured area," said Eduardo Marbán, M.D., director of the Cedars-Sinai Heart Institute. "Once injected into a patient's artery, many stem cells are lost due to the combination of tissue blood flow, which can wash out stem cells, and cardiac contraction, which can squeeze out stem cells. We needed to find a way to guide more of the cells directly to the area of the heart that we want to heal."
Marbán's team, including Ke Cheng, Ph.D. and other researchers, then began a new animal investigation, loading cardiac stem cells with micro-size iron particles. The iron-loaded cells were then injected into rats with a heart attack. When a toy magnet was placed externally above the heart and close to the damaged heart muscle, the stem cells clustered at the site of injury, retention of cells in the heart tripled, and the injected cells went on to heal the heart more effectively.
"Tissue viability is enhanced and heart function is greater with magnetic targeting," said Marbán, who holds the Mark Siegel Family Foundation Chair at the Cedars-Sinai Heart Institute and directs Cedars-Sinai's Board of Governors Heart Stem Cell Center. "This remarkably simple method could easily be coupled with current stem cell treatments to enhance their effectiveness." _Physorg
Image Source

The combination of stem cells with nanotechnology provides another synergistic surprise, loaded with hope for future cures and life extension potential.

Tomorrow's medical treatments will be more individualised, more targeted to specific systems and tissues. As a result, the collateral damage will be lessened, interventional dosing and exposure can be moderated, and a desired outcome can be made more likely.

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Wednesday, April 07, 2010

Human Cell Aging Reversed by Biotime

Biotime researchers report the successful resetting of the "age clock" of mature human cells back to the embryonic age. This was apparently accomplished using telomeric technology similar to what Geron has been working on.
In the article, BioTime and its collaborators demonstrate the successful reversal of the developmental aging of normal human cells. Using precise genetic modifications, normal human cells were induced to reverse both the "clock" of differentiation (the process by which an embryonic stem cell becomes the many specialized differentiated cell types of the body), and the "clock" of cellular aging (telomere length). As a result, aged differentiated cells became young stem cells capable of regeneration.
_NextBigFuture


More links, videos, and information from Brian Wang and at the BioTime website.

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Monday, November 09, 2009

Stem Cell Advances

Any adult cell can become a stem cell. This is a striking finding from the Cambridge, Mass. researchers.
“Essentially, all cells have the potential to become pluripotent. It is something that seems to happen to the cells under these conditions stochastically — that is, in a continuous, but probabilistic fashion,” Jaenisch explains. _Softpedia


Stem cell treatment restores limb function in rats with cervical spine injuries. The UCI team used human embryonic stem cells (pre-oligodendrocytes) that "rebuilt myelin, stopped tissue death and triggered nerve fiber regrowth".

Patients with advanced leukemia successfully treated with stem cells. Of the 58 patients, 35% survived 3 years -- an exceptionally good result for patients at such an advanced stage.

New technique developed to separate "safe" from "unsafe" stem cells before therapy. Stem cells vary in their likelihood to grow out of control and cause malignancies. "Undifferentiated" stem cells are more likely to lose control of growth.
Scientists from Invitrogen and the Buck Institute for Age Research, located in Novato, California, collaborated in developing this innovative solution that depletes greater than 99% of undifferentiated human embryonic stem cells from differentiated populations. They are presenting data on this new technology at the International Society for Cellular Therapy Meeting in San Diego. __LabmateOnline


Stem cells provide the bricks and mortar for constructing human tissues and organs. We are just beginning to learn how to create them, and to use them safely and efficaciously. In ten years -- if the US biomedical system has not been completely destroyed by government intervention -- we will look back to the present, amazed that human medicine was ever so primitive and hopelessly ineffective.

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Tuesday, March 10, 2009

A Realistic Look at Obama's Stem Cell Order

President Obama's long anticipated and much heralded signing of new federal guidelines for the financing of embryonic stem cell research will help US scientists learn more of the mysteries of embryonic cell differentiation and manipulation. But in reality, the effect of the new rules will be far less significant for the future of regenerative medicine than most gullible news consumers will ever know.
.....the president’s support of embryonic stem cell research comes at a time when many advances have been made with other sorts of stem cells. The Japanese biologist Shinya Yamanaka found in 2007 that adult cells could be reprogrammed to an embryonic state with surprising ease. This technology “may eventually eclipse the embryonic stem cell lines for therapeutic as well as diagnostics applications,” Dr. Kriegstein said. For researchers, reprogramming an adult cell can be much more convenient, and there have never been any restrictions on working with adult stem cells.

For therapy, far off as that is, treating patients with their own cells would avoid the problem of immune rejection.

Members of Congress and advocates for fighting diseases have long spoken of human embryonic stem cell research as if it were a sure avenue to quick cures for intractable afflictions. Scientists have not publicly objected to such high-flown hopes, which have helped fuel new sources of grant money like the $3 billion initiative in California for stem cell research.

In private, however, many researchers have projected much more modest goals for embryonic stem cells. Their chief interest is to derive embryonic stem cell lines from patients with specific diseases, and by tracking the cells in the test tube to develop basic knowledge about how the disease develops.

Despite an F.D.A.-approved safety test of embryonic stem cells in spinal cord injury that the Geron Corporation began in January, many scientists believe that putting stem-cell-derived tissues into patients lies a long way off. Embryonic stem cells have their drawbacks. They cause tumors, and the adult cells derived from them may be rejected by the patient’s immune system. Furthermore, whatever disease process caused the patients’ tissue cells to die is likely to kill introduced cells as well. All these problems may be solvable, but so far none have been solved.

Restrictions on embryonic stem cell research originated with Congress, which, each year since in 1996, has forbidden the use of federal financing for any experiment in which a human embryo is destroyed. This includes the derivation of human stem cell lines from surplus fertility clinic embryos, first achieved by Dr. James Thomson of the University of Wisconsin in 1998.

President Clinton contemplated but never implemented a policy that would have allowed N.I.H.-financed researchers to study human embryonic stem cells derived by others. Research was able to begin only in August 2001, when President Bush, seeking a different way around the Congressional restriction, said researchers could use any lines established before that date.

Critics said the distinction between the Clinton and Bush policies lacked moral significance, given that each was intended to get around the Congressional ban, based on a religious and moral argument. The proposed Clinton policy amounted to: “Stealing is wrong, but it’s O.K. to use stolen property if someone else stole it.” The Bush policy was: “Stealing is wrong, but it’s O.K. to use stolen property if it was stolen before Aug. 9, 2001.”

Mr. Obama has put the proposed Clinton policy into effect, but Congressional restrictions remain. Researchers are still forbidden to use federal financing to derive new human embryonic stem cell lines. They will, however, be allowed to do research on new stem cell lines grown in a privately financed lab. _NYT
More research on embryonic stem cells will help scientists understand the intricate mechanisms of cell development. They will acquire a fabulous treasure trove of knowledge about many diseases -- both rare and less rare. The knowledge spinoffs from this research will stretch far beyond regenerative medicine (RM) to cancer treatments, life extension technologies other than RM, and a much deeper understanding of biological mechanisms in general.

But all of that would have occurred without that much celebrated penstroke yesterday. And it is undeniable that the flow of NIH funds to non-embryonic stem cell research has been a boon to technologies that are more immediately applicable to the everyday regenerative cell and tissue treatments of the future -- treatment using the patient's own cells.

Science under Obama is every bit as political as science under any other president -- and will probably only grow more political with time. Obama's promotion of carbon penalties (disguised as "cap and trade") are a politicised hyping of the pseudo science of catastrophic global warming from anthropogenic CO2. Obama's carbon hysteria-based political meddling in the energy industry is likely to make Americans far more miserable, leaving them with far less resources to deal with exigencies, than if he had done nothing at all.

So let's celebrate the abundant biological future that will eventually come to us via all the avenues of research being followed. And let us not fall for the hype surrounding the gilded age of Obamanation.

Taken from an earlier posting at Al Fin

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Sunday, March 01, 2009

More Engineered Stem Cell News

Toronto's Samuel Lunenfeld Research Institute at Mt. Sinai Hospital is the site of groundbreaking research on engineered stem cells.
"We hope that these stem cells will form the basis for treatment for many diseases and conditions that are currently considered incurable," said Dr. Nagy, Senior Investigator at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Investigator at the McEwen Centre for Regenerative Medicine, and Canada Research Chair in Stem Cells and Regeneration. "This new method of generating stem cells does not require embryos as starting points and could be used to generate cells from many adult tissues such as a patient's own skin cells."

Dr. Nagy discovered a new method to create pluripotent stem cells (cells that can develop into most other cell types) without disrupting healthy genes. Dr. Nagy's method uses a novel wrapping procedure to deliver specific genes to reprogram cells into stem cells. Previous approaches required the use of viruses to deliver the required genes, a method that carries the risk of damaging the DNA. Dr. Nagy's method does not require viruses, and so overcomes a major hurdle for the future of safe, personalized stem cell therapies in humans.

"This research is a huge step forward on the path to new stem cell-based therapies and indicates that researchers at the Lunenfeld are at the leading edge of regenerative medicine," said Dr. Jim Woodgett, Director of Research for the Samuel Lunenfeld Research Institute of Mount Sinai Hospital. Regenerative medicine refers to enabling the human body to repair, replace, restore and regenerate its own damaged or diseased cells, tissues and organs. _PO
The new method avoids the risks of tumourogenesis that come with using viruses for reprogramming cells into stem cells. Various new and potent techniques of producing virtually any stem cell type from adult cells bring modern biomedicine ever closer to the ability to replace and / or rejuvenate virtually any tissues in the body -- using the person's own cells!

There is still much to be learned about the genetic switching mechanisms involved. Until we are certain that the re-programming techniques can truly provide safe, long-lived replacement cells for the various tissues of the body, we will need to continue experimenting with embryonic stem cell lines as well as with the re-programmed stem cells.

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Tuesday, February 17, 2009

New Stem Cell Hope For Parkinson's

Researchers in Bonn have developed a method of culturing an indefinite supply of replacement neural stem cells -- including the cells that fail in Parkinson's -- from a single embryonic source.
"The new cells, in contrast, serve as an inexhaustible source: they provide a supply of human neural cells over periods of months and years without demanding any recourse to supplementary embryonic stem cells", declares Professor Dr. Oliver Brüstle, head of the research team at the Institute for Reconstructive Neurobiology at Bonn University.

Using animal experiments, the researchers in Bonn provided direct proof that these artificially derived neural cells will also function. Transplanted into the brain of a mouse, these cells made contact with the recipient brain and were subsequently able both to send and receive signals. "This is the first direct evidence that neural cells derived from human stem cells are capable of synaptic integration in the brain", declares Dr. Philipp Koch, the original author of the study. The scientists in Bonn are now also hoping to exploit this inexhaustible cell source to study neurodegenerative diseases and possible active agents directly in human neural cells. _MNT
If scientists can prevent the rejection of donor stem cells, the pathway toward routine replacement of aging brain tissue is now being constructed. Adult induced pluripotent stem cells from the patient herself is the best means for preventing rejection of tissue and stem cell implants. But if embryonic cell and tissue banks are able to carry a large "on-demand" supply of suitable cells, they will be quite useful.

Clearly the promise of stem cell research applies to other diseases besides Parkinson's, and to other organs besides the brain.

The problem for the US -- where funding for the development of new embryonic stem cell lines is expected to be expanded -- is the overall economy. The new government appears not to understand how a market economy recovers from a recession -- a recession that was brought on by bad government policies to begin with. A helpful hint to Obama and Pelosi: get rid of those bad government policies! (CRA etc)

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Saturday, February 14, 2009

Interferon Makes Dormant Cells Vulnerable

Dormancy is an important protection mechanism of stem cells. First, it protects their genetic material from genetic alterations, which happen primarily during cell division. In addition, dormancy helps them escape attacks of many cytotoxins, which act only on dividing cells. _MNT
Many cancer stem cells are likewise dormant, which can protect them from chemotherapy. Waking these cancer stem cells up before chemotherapy is one way to kill more of them, and increasing chances for a remission. Interferon seems to wake stem cells up from a dormant state, and force them to divide. This makes them vulnerable to mutation and to cytotoxins.
Patients suffering from a type of blood cancer called chronic myelogenous leukemia who are treated with a drug called Gleevec almost always relapse after drug treatment has ended. Several patients were given interferon-alpha prior to the Gleevec treatment. Surprisingly, these patients experienced long relapse-free phases without any medication. "We believe that the leukemia stem cells were awakened by the interferon administration and, thus, were sensitized to elimination by Gleevec," Andreas Trumpp explains. _MNT
The other side of the story is that interferon makes normal stem cells vulnerable to cytotoxic agents, so that blood forming stem cells in the bone marrow will be killed by some chemotherapeutic agents such as 5-FU, if interferon is given first. This can cause severe anemia and death.

This knowledge can lead one to speculate about the effects of viral infections and natural interferon on stem cells in other locations, such as the brain. The constant infectious assault experienced in the tropics, for example, may lead to chronic depletion of stem cells with all of the failure of normal regeneration that such depletion implies.

Each scientific discovery becomes the trigger for new exploration. The contemporary human mind cannot keep up with the multiple ongoing chain reactions of knowledge, but computers should be of some help.

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Thursday, February 12, 2009

Skin Cells Programmed to Become Heart Cells

Using techniques of induced pluripotent stem cell conversion, scientists at the University of Wisconsin created heart cells out of skin cells. The idea is to take a person with heart failure, make functioning replacement heart cells from abundant skin cells, and give the person what is in essence a new heart.
"This is the first demonstration that human induced cells can form different types of heart cells in a dish," said study co-author Tim Kamp, a University of Wisconsin cell biologist.

The latest findings, published Thursday in Circulation Research, suggests that failing hearts might be mended.

"We didn't know whether they could form heart cells efficiently," said Kamp. "But they successfully formed heart cells with all the electrical and organizational properties we'd expect."

In the last few years, induced pluripotency has been hailed as an uncontroversial alternative to embryonic stem cells, production of which requires the destruction of embryos.

Reprogramming flakes of skin would be a far easier alternative. _Wired

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