An eye into the future

A few months ago, I wrote a post about a recent trial that had been carried out using embryonic stem cells to treat diseases of the eye. The trial was carried out on two patients with different conditions: One with age-related macular degeneration - the leading cause of blindness in the developed world - and another patient in her 50s with Stargardt's disease.

This week we have learnt about an experimental treatment using skin cells to improve the vision of blind mice which may help those with macular degeneration. The fact that the trial involved induced pluripotent stem cells as opposed to embryonic stem cells could dispel concerns initially raised about the ethical implications. Another benefit is that patients would not need drugs to prevent rejection of the transplanted cells.

It's often said that induced pluripotent stem cells transplantation will be important in the practice of medicine in some distant future, but scientists are keen to suggest the future is almost here.

The study was published online in advance of print in the journal Molecular Medicine. 

Stem cell therapy against HIV in mice

Sorry I haven't posted in while.... I've had quite an intense week of exams! I recently finished an immunology module in biology, so this article particulary caught my attention:

Stem cell therapy effective against HIV (in mice)!

The way it works is by replacing the mouse's immune system with stem cells engineered with a triple combination of HIV-resistant genes.

The scientists running the trial, were able to block HIV infection, maintain a normal immune system in the mice, even though the virus was still there. The resistant immune cells were able to maintain a normal immune cell level and maintain a functional immune system.

If in the future these trials in humans proved successful, it could allow patients to stop taking antiretroviral drugs as the genetically resistant stem cells wiould be able to fight off the virus in the body.

A step too far?

“The first human egg cells that have been grown entirely in the laboratory from stem cells could be fertilised later this year in a development that will revolutionise fertility treatment.” - Reading this first line in an article in The Independent today has made me feel a mixture of emotions.

Great it could lead to a reversal of the menopause in older women allowing them not to suffer the age-related health problems associated with the menopause such as osteoporosis and heart disease, and of course this “breakthrough” could help infertile women to have babies as well as making women as fertile in later life as men. BUT….. If scientists were to go through with this they obviously haven't thought of the potential IMPLICATIONS. Imagine an 80 year old woman giving birth.

Scientists are near to being granted a license from the UK fertility watchdog to fertilise the eggs as part of a series of tests to generate an unlimited supply of human eggs. The scientists want to fertilise the laboratory-grown egg cells with human sperm to prove that they are viable. Any resulting embryos will be studied for up to 14 days - the legal limit - to see if they are normal. These embryos will either be frozen or allowed to perish as they are considered “experimental” material and therefore legally cannot be transplanted into a woman's womb.

Who defines the limits of modern science and where are those limits? How far is too far?

Please comment and share your views!!

A step forward in treating coronary artery disease

Chronic ischemic heart disease (IHD) otherwise known as coronary artery disease is one of the major causes of death worldwide, most common with the passing of years. It usually occurs due to a partial blockage of blood flow to the heart. At times, the heart fails to get essential blood to work normally, in this situation it has no other way except to work harder which leads it to become starved for oxygen. The complete blockage of blood flow to the heart is what can cause a myocardial infarction.

The pharmaceutical giant, Baxter, is developing a treatment which uses patients' own stem cells to repair damage to the heart. Were this phase III trial to be successful it would represent the last step in the clinical development process before submission by the regulatory authorities and, hopefully, approval and commercialisation. Unlike some of the other recent stem cell trials to repair heart this procedure uses stem cells from a patient's bone marrow that are normally involved in the creation of new blood vessels.

In the procedure these CD34+ cells are stimulated to grow and multiply, before being induced to enter the bloodstream. The cells are then collected, processed and injected into targeted areas of the heart.

Around 450 patients will be enrolled in the trial and split into three treatment groups:

·         one group who will receive the therapy,

·         one group who will receive placebo

·         third group who will receive standard medical care

Ability to exercise one year after therapy will be a key indicator of the treatment's effectiveness. Doctors will also collect safety data for two years following the start of the therapy. The current trial follows on from a phase II study, where the CD34+ stem cell treatment improved exercise capacity and reduced chest pain.

http://www.bionews.org.uk/page_131543.asp

The real wonders of stem cells

Sorry this article is a week old but have a peek because it won't fail to amaze you!


http://www.bbc.co.uk/news/health-17012688

Katie Piper's story - The science of seeing again

Channel 4’s documentary – “The science of seeing again” was a wonderful example of the application of stem cells in tissue regeneration. Presented by Katie piper, an acid attack victim, the documentary follows her brave journey through the treatment and post-operative care. Katie suffered serious burns in 2008 following an acid attack by her ex boyfriend, which also left her blinded in her left eye.

After enduring 4 years of constant operations totaling more than 100, she decided to approach Dr sheraz Daya, a leading surgeon and pioneer in stem cell technology, after seeing him on TV talking about a new stem cell procedure for the eye. What struck me the most about Katie was her courage and determination.

Her surgery took place in November at the Queen Victoria Hospital in West Sussex and involved the grafting of donor stem cells from the cornea into katie’s damaged eye after the corneal stem cells were cultured in the laboratory. The results appear positive with surgery having removed the abnormal cells in the eye and the stem cells promoting healthy cell growth and repair.

How it all works:

The stem cell procedure carried out by the doctor used the limbal tissue (at the border of the white of the eye and the clear cornea)from a male donor and cultivated the stem cells from that tissue in the laboratory before transplanting them into Katie Piper’s damaged left eye. Before the transplant takes place however, the patient’s existing scar tissue and abnormal blood vessel growth requires removal from the surface of the eye. The stem cells are then covered with a thin piece of tissue membrane taken from the womb lining as this encourages cell growth and provides scaffolding for the corneal stem cells.

Prior to the operation Piper could only discern light and dark. Following the stem cell transplant she has regained enough vision to detect depth, movement, and even facial features with gradual improvements in her sight over the three months since surgery.

After all Katie’s been through in these last years, she definitely deserves all the luck she can get!

Click on the link below to watch the programme in full:

http://www.channel4.com/programmes/katie-the-science-of-seeing-again/4od

Rejection from Edinburgh...

Just received my second rejection, this time from Edinburgh. Can't say I wasn't expecting it but that doesn't take away the disappointment :(
Ahh.....the joy of medical applications....

Embryonic cells to treat diseases of the eye: ethical or not?

Early results from the world's first human trial using embryonic stem cells to treat diseases of the eye suggest the method is safe.

The trial was carried out on two patients with different conditions of the eye: One elderly patient in her 70s with dry age-related macular degeneration - the leading cause of blindness in the developed world - and another female patient in her 50s with Stargardt's disease.

Stargardt's disease

ABCA4 is the gene associated with stargardt’s disease. It produces a protein involved in energy transport to and from photoreceptor cells in the retina. Mutations in the ABCA4 gene, produce a dysfunctional protein that cannot perform its transport function. The non-functional ABCA4 protein permits the accumulation of yellow fatty material to accumulate in the retina. This material causes flecks and, ultimately, loss of vision. 

It has been reported in The Lancet that the two patients who received the retinal implants were doing well four months on. London's Moorfields Eye Hospital is now conducting a similar trial. Although these preliminary results seem promising, it could be years before the treatments are proven.

The treatment involves taking healthy immature cells from a human embryo, which are then manipulated to grow into the cells that line the back of the eye - the retina.

Researchers hope injecting these cells into a diseased eye will be able to restore vision for people with currently incurable conditions such as Stargardt's disease. The injection contained 50,000 of the retinal pigment epithelium cells.

After surgery, it was confirmed that the cells had attached to the eye's membrane as hoped, and continued to survive throughout the next 16 weeks of the study. Therefore, the procedure appeared to be safe, causing no signs of rejection or abnormal cell growth.

Despite the initial positive results of this trial, we can’t turn a “blind eye” to the ethical questions it poses.  

Professor Clynes, director of the National Institute of Cellular Biotechnology, recently stated: “It comes fundamentally to the question: is anything that is technologically possible acceptable if it cures a disease – and I’d say not.” I would tend to agree with the professor, but what are your views?


www.bbc.co.uk/health

Merry Christmas

It’s Christmas!!

Merry Christmas and Happy New Year to you all. Let’s hope this incoming year brings us happiness, prosperity and great medical advances in stem cell research!

I'm back!!!

After two intense weeks of exams, i´m finally back! God those exams were hard especially the physics one! At least I can get back to what I really love: blogging and medicine J Although I’ve been busy with exams, I've tried to keep up to date with the latest news, here’s a summary of the main events of these past two weeks:

• Platelets produced from stem cells:

Once again researchers at Kyoto are at the centre of discussion. It’s been reported that scientists at this institution have been able to create for the first time platelet cells by reprogramming stem cells derived from the adult form. 

Induced pluripotent stem cells, (iPS) are produced by manipulating ordinary human skin or blood cells back to a state in which they are able to differentiate into a number of different cell types. When they were first discovered in 2006,  they looked like the perfect alternative to embryonic stem cells,  however the process of producing non-mutated cells has proved challenging. The limitation in using this method has been the ability to find a method that creates a large number of high-quality, functional platelets.

The Japanese researchers set out to create a cell line with a large number of high-quality megakaryocytes from stem cells that can be grown indefinitely and differentiate into a variety of cell types in the body. They were able to produce a cell line that turned off certain genes to generate functional platelets. They then tested the cultured platelets by infusing them into immunodeficient mouse models and confirmed that they had the same life span as human platelets infused in mice.

This has the potential of taking us forward to a day when we might be able to eliminate blood platelet shortages. This type of blood cell intervenes in the coagulation process: platelets stick together and form a plug at the site of an injured blood vessel, allowing the injured site to heal.

World’s first stem cell bandage

(This is for all you sports enthusiasts out there…)

A pioneering stem cell bandage, believed to be the world’s first adult stem cell treatment designed to heal torn meniscal cartilage, has been approved for human clinical trials.

This cell Bandage is seen as an alternative to the common treatment of surgical removal of the meniscus (meniscectomy), a procedure that 1.7 million people around the world undergo per year. This procedure often results in the early onset of osteoarthritis, leading to further joint surgery including total knee replacement.

The Cell Bandage has shown great promise for the healing of meniscal tears. It´s grown from the patient’s own stem cells and is trasplanted in the patient’s knee joint within two weeks of extracting the stem cells from bone marrow.

The treatment process begins with bone marrow being extracted from the patient's hip, using a needle. Stem cells are then grown from that bone marrow in a laboratory, and seeded onto a special membrane. That membrane is subsequently inserted into the tear, and the cartilage is sewn up around it to hold it in place. The idea is that the stem cells will proceed to become cartilage cells, and speed the regrowth of what might have otherwise been an unsalvageable meniscus.

 

The effective repair of meniscal tears would represent a significant advance in treatment, particularly for younger patients and athletes.

iPSC | Timeline

Hi guys! Thought i would post a timeline of all the main breakthroughs in reprogrammed stem cell research (iPSC - Induced pluripotent stem cells) in the last 10 years:

Reprogrammed stem cells are adult cells turned back into a stem-like state, restoring their lost potential.

CLICK ON THE LINK TO VIEW THE TIMELINE IN FULL WITH THE DESCRIPTIONS: iPSC | View timeline

Stem cells from the "tooth fairy"

Doctors in India are looking at ways to turn “dental pulp” (part in the centre of a tooth made up of living connective tissue and cells called odontoblasts into heart cells under stem cell treatment.

The main doctor conducting the investigation – Dr Mohanty said: “The Mesenchymal type of stem cell inside the dental pulp are multipotent stem cells that have the potential to differentiate into a variety of cell types which can contribute to replacing muscle tissues or internal organs.”

In previous posts, we have talked a lot about pluripotent stem cells extracted from the skin known as IPSC (Induced pluripotent stem cells). But what other types of stem cells are there?

The three main types are:

• Totipotent: it has the potential to become all other types of cells in the body. A fertilized egg is totipotent.
• Multipotent: a small number of stem cells can produce only certain types of cells.
• Pluripotent: stem cells that produce any type of cell in the body except those needed to develop a fetus.

Bone marrow and umbilical cord blood stem cells are undoubtedly present as a good source of stem cells but acquiring them is a tedious process. Extracting cells from dental pulp could be an easier and a non-invasive way unlike extracting bone marrow stem cells from bones which involve injecting into bones.

Turning back the clock

Could you ever have imagined possible to transform cells from patients as old as 100 into stem cells virtually identical to those found in embryos? Researchers from the University of Montpellier have done just that!

If these can be used to grow healthy tissue which can safely be transplanted into elderly patients it could open up new avenues of treatment for the elderly. This investigation could potentially revolutionize our concept of “cell rejuvenation” ... the age of cells is definitely not a barrier to reprogramming.

Embryonic stem cells can grow into any type of tissue in the body, and scientists hope they could one day be used to replace diseased organs with healthy, lab-grown replacements. But their use in medicine is controversial because it involves the destruction of human embryos, albeit at a very early stage.

The alternative method is taking normal cells from adults and reversing them to an unspecialised state, known as induced pluripotent stem cells (iPS), making them almost indistinguishable from embryonic stem cells. However this could prove to be less effective especially in elderly patients, who have the most to gain from the potential treatments, because their cells have deteriorated further.

By adding two new ingredients, known as transcription factors, to the method of generating adult stem cells, scientists were able to overcome this hurdle and "reset" many of the key markers of ageing in cells.  These two new transcription factors are NANOG and LIN28.

LIN28

Transcription factors are proteins that bind to DNA to control the transcription of a unique set of genes.

Stem-cell find breathes new life into lung repair - health - 28 October 2011 - New Scientist

Stem-cell find breathes new life into lung repair - health - 28 October 2011 - New Scientist


Take a look at this article from the New Scientist!

Gut stem cell secrets

A new study from University of California, Berkeley, demonstrates that adult stem cells can reshape our organs in response to changes in the body and the environment. The findings could have implications in the therapeutic use of stem cells for treatment of different gastrointestinal and metabolic disorders such as diabetes.

Our current understanding has been that, once embryonic stem cells mature into adult stem cells, they sit quietly in our tissues, replacing cells that die or are injured but doing little else.But in working with fruit flies, the researchers found that intestinal stem cells responded to increased food intake by producing more intestinal cells, expanding the size of the intestines as long as the food keeps flowing. Just as in humans and other mammals, the fly intestine secretes its own insulin. In flies, intestinal insulin seems to be the signal that makes stem cells “supersize the gut.” This discovery may hold a key to understanding how human organs adapt to environmental change.

Human intestines regrow after portions have been surgically removed because of cancer or injury, and hibernating animals see their intestines shrink to one-third their normal size during winter. Stem cells can divide either asymmetrically, producing one stem cell and one intestinal cell, or symmetrically, producing two stem cells. The team found that, in response to food, intestinal stem cells underwent symmetric division more frequently than asymmetric division, which had the effect of maintaining the proportion of stem cells to intestinal cells, and is a more efficient way of ramping up the total number of cells.

Upkeep of the intestinal lining is metabolically expensive, consuming up to 30 percent of the body’s energy resources. By minimizing intestinal size when food is scarce, and maximizing digestive capacity when food is abundant, adaptive intestinal resizing by stem cells helps animals survive in constantly changing environments.

Diabetes could soon be a thing of the past

Artificial blood from stem cells

Pioneering research that is currently being carried out at the University of Edinburgh is proving so successful that within two years, Britons could be injected with artificial blood.

The blood, made from stem cells, would transform blood transfusions by preventing shortages in hospitals and prove a lifesaver in emergency events. It would carry a much lower risk of infection than the real thing and could be given to almost everyone regardless of their blood group.

They have already worked out how to make thousands of millions of red blood cells from stem cells taken from adults’ bone marrow. But with the average blood transfusion containing 2.5million million red blood cells, it just isn’t enough. Cells taken from human embryos in the first days of life are easier to multiply in large numbers but the researchers have so far not managed to make such realistic blood from them. Other possibilities include transforming pluripotent skin cells into red blood cells.

A ready supply of safe blood would also be a boon in developing and third world countries, where thousands of lives are lost unnecessarily each year to conditions such as haemorrhages after child birth.

The main researcher, Professor Turner, predicts that in two to three years, he will be ready to inject a teaspoon of artificial blood into healthy volunteers, in the first British trial of blood made from stem cells. Other researchers are making haemoglobin, the red blood cell protein used to transport oxygen around the body.

Any embryonic stem cells used would be taken from five-day-old embryos left over from IVF treatment and donated to the research project by the patients.

Best of British

British researchers have made significant progress in using stem cells for treating hereditary diseases in the future.

Induced pluripotent stem cells (iPS cells) (SEE THE WACKY SCIENTIST) were used, taken from the skin cells of patients with a metabolism disorder. They changed these cells into cells like those in the liver and then introduced the human cells "cured" in this way into mice with the metabolic disorder.

The hereditary metabolic disease concerned is called Alpha-1-antitrypsin Deficiency, which occurs as the result of the mutation of a single gene (monogenic disorder).Both copies of the relevant genes in the patient need to be changed for the disease to show symptoms. According to the authors, the disease affects one in 2 000 people of northern European origin and can lead to cirrhosis of the liver, which in turn could necessitate a liver transplant.

Alpha 1-antitrypsin is a protease inhibitor belonging to the serpin superfamily. It inhibits a wide variety of proteases and protects tissues from enzymes of inflammatory cells, especially neutrophil elastase. In its absence, neutrophil elastase is free to break down elastin, which contributes to the elasticity of the lungs, resulting in respiratory complications such as emphysema and cirrhosis in adults or children.

Skin cells were taken from three patients with metabolic disease. Stem cells like these are seen as an ethically unproblematic alternative to embryonic stem cells, as they are not drawn from embryos. In the future they are set to be used in cell therapy for a variety of diseases.

As no tumour cells formed in the mice as a result of the intervention - by contrast with similar trials - the study authors believe the possibility exists of making progress using this method in treating monogenic diseases. The human cells apparently integrated into the liver tissue of the mice, taking over their function there. However, the altered iPS cells received mutations in their genetic makeup.

The power of breast milk

A remarkable discovery has recently been made at the University of Western Australia: Serious and fatal diseases such as pancreatic cancer, Parkinson's disease and diabetes may eventually be treated using stem cells from breast milk.

PhD student Foteini Hassiotou has potentially broken through the greatest hurdle in stem cell research - the ability to ethically obtain stem cells in a non-invasive manner, which by anyone´s standards is a significant breakthrough

She was able to conclude that stem cells from breast milk can be directed to become other body cell types such as bone, fat, liver and brain cells, potentially reducing the need to use embryonic stem cells and therefore fast-tracking future therapies. Back in 2008 researchers at this same university discovered that breast milk contained embryonic-like stem cells. Dr Hassiotou will test her hypothesis by conducting animal transplants during the next few months.

This discovery raises many other issues such as what role stem cells play in the development of the infant once they´ve been ingested.

For lovers of science, stem cell therapy holds a lot of promise and is ultimately the therapy of the future.

Embryonic stem cells for human therapeutic use?

As many of you will have heard, a form of cloning has recently been used to create personalised embryonic stem cells in humans.

Genetic material was taken from an adult skin cell and transferred into a human egg. This was grown to produce an early embryo. However, the stem cells formed contained chromosomes from both the adult and the egg cells. The technique used - somatic cell nuclear transfer - shot to fame in 1997 when Dolly the sheep, the first mammal to be cloned from an adult cell, was unveiled to the world.

Trials involving removing the genetic material from the egg and replaced it with the chromosomes from a skin cell, proved unsuccessful as the egg divided but failed to go past the 6-12 cell stage. In contrast, when the egg's own genetic material was left in place and the skin chromosomes were added, the egg developed. It reached the blastocyst stage, which can contain up to 100 cells and is the usual source of embryonic stem cells.

In this technique the two adult copies are added to the single copy in the egg meaning a total of three, which can be problematic. Often embryos without the correct number of chromosomes do not develop at all. Down's syndrome is caused by three copies of just one chromosome.

Researchers will need to produce embryonic cells which have only donor DNA, however, once the egg starts to divide the chromosomes are combined in the nucleus and would be near impossible to separate.

This research shows that the traditional approach to somatic cell nuclear transfer is inefficient in humans, whereas leaving the host egg genome in place increases efficiency.

Using embryonic cells does raise significant ethical dilemmas. Recently a different route to stem cells has been used. Instead of using an egg, a chemical bath "reprogrammes" an adult cell into a stem cell. While this is seen as more ethical, there are concerns about whether such cells could be used therapeutically. There are differences between embryonic and "induced" stem cells, with the latter being more prone to expressing cancer causing genes.

Source: www.genengnews.com; bbc.co.uk