Stem Cell Lineage
Stem cells form the basis behind which the human body and the bodies of other living organisms successfully develop and maintain themselves over years. Imbued with the natural potential to replicate and “stem” into any other tissue (a process of genetic differentiation that gives them their name), stem cells must regularly go through two separate processes on a regular basis in order to maintain functionality: symmetric replication and asymmetric replication.
Symmetric replication is a process where a single stem cell divides into two identical daughter cells, each containing the initial stem cell ability to replicate additional stem cells. This allows for stem cells to regularly grow and replace dead or damaged cells without lessening their numbers, closing off systems that would otherwise be compromised without their presence.
Asymmetric replication, on the other hand, creates what is known as a progenitor cell in addition to a standard stem cell. Progenitor cells unlike stem cells can only replicate a certain number of times before being forced to permanently differentiate into a specific cell structure and become part of a set body system. This process both works to limit stem cell population growth as well as allow for the stem cells to assist other structures as necessary – their primary role in maintaining body functionality through ensured system sustainability.
Currently there are two primary theories as to why stem cells go through symmetric division at one point and asymmetric at another. One theory is that the protein receptors found within the cell membrane of each daughter cell determine at any given time whether or not the cell will be a symmetric or asymmetric offspring, adjusting based upon specific codes within the original stem cell that may be received through the body’s natural messaging processes.
A second theory, on the other hand, states that stem cells replicate either symmetrically or asymmetrically based upon environmental factors that surround them at any given time. While in a set environment, for instance, they retain symmetric division, however as new elements are introduced into their environment the cells react accordingly and differentiate to meet their specific needs. Studies have shown this to be an active factor in cell division within some organic structures, however the lack of applicability to all systems (at least the proven lack at this time) means that this is still but a theory and not a proven scientific principal as of yet.
Subscribe to the comments for this postiPSCs Retain Genetic Memory
A study of induced pluripotent stem cells (iPSCs) where cells harvested from differentiated adult cell lines and forced to be converted into highly adaptive states (similar to that of totipotent embryonic stem cells) has found that these cells retain a portion of their previous genetic code even after being cultured to grow towards a specific cell structure. This effectively means that while scientists can develop multi-functional cells from adult differentiated cell lines that they may not be able to do so effectively in a short span of time after harvesting the cells, posting new problems and benefits at the same time to stem cell research developers.
On a positive note the partially retaining stem cells can be a boon in many areas. Retaining portions of their previously encoded DNA, these cells may more easily be adapted to fit specific purposes similar to those they originate from, meaning easier conversion from a donor to a host needing support in a specific cell structure should this be necessary. Additionally the genetic memory means that progressive structures will maintain slightly different codes from targeted formats meaning that some genetic diversity can be generated even in scientifically cloned organisms, such as that which has been observed in laboratory mice created from the same host DNA.
On the downside this reminiscent code present in harvested cells means that additional work must be done in order to develop cell lines into targeted structures to match specific needs. Should a harvested cell be modified to develop into brain, nerve or other tissue cells within the same body but not fully differentiate towards the targeted structure, for instance, any treatment that is developed but still partially coded for another cell line may fail in terms of treatment and cause additional problems for a patient – even if the treatment is not rejected outright from the body.
Thankfully for many patients and researchers alike the genetic memory found in iPSCs has also been noted to progressively becoming less and less prominent through subsequent divisions of a harvested cell culture. This means that regularly culturing the same iPSC strand through successive generations can reduce the overall impact the genetic memory will have, with the memory disappearing entirely from cell lines at approximately the 16th division. While this does unfortunately mean that some treatments relying upon iPSCs may take some time for the cultures to develop fully enough to the point where they can be used to treat patients at the same time this does not mean that iPSCs are ruled out entirely as an option.
How embryonic stem cell lines are made
Embryonic stem cells are a highly sought after form of stem cell with the capability to be used in a number of different medical processes (though unfortunately they also carry with them a hefty ethical debate that prevents them from being widely studied and used at this time as well). The reason for the highly effectiveness of embryonic stem cells lies in the fact that they have not differentiated into any particular tissue or function as of yet and therefore are totipotent (also known as omnipotent), or otherwise capable of becoming virtually any biological structure they are encouraged to develop into.
In order to allow this differentiation into desired structures to occur embryonic stem cells must first be harvested from a developing blastocyst, or newly forming embryonic cell structure that forms approximately one week after a sperm successfully fertilizes an egg. These are removed from the center of the blastocyst and deposited into a growth tray for nurturing and culturing into a desired cell structure. Until the culture material is adjusted to encourage growth of a particular cell, however, the harvested cells will continue to grow and under ideal conditions will do so indefinitely so long as they never differentiate into a specific cell structure – such is the nature of stem cells as their basic function is to replicate in order to allow for other cell structures to form and differentiate into more durable structures that our body needs to function (such as tissue, nerve and bone cells).
Once the desired cell structure has been chosen for the cells to form into the nutrient content and growth conditions of the culture dish are altered in order to encourage growth to a particular cellular structure. Sometimes this can also involve the direct modification of the cell’s DNA to create a dedicated cellular structure base upon a set DNA strand (such as brain tissue or blood vessels) to specify a growth structure. By doing this the embryonic cells can be forced to differentiate into any number of cellular forms necessary for a body to function and be applied medically to treat a number of ailments, in particular any tissues or systems that may have been damaged due to trauma or other cellular disorder that damages cells and renders them unable to repair themselves (such as the case with nerve damage due to the highly differentiated nature of nerve cells and their inability to actively repair themselves like skin or other tissue cells).
Stem Cells Neurological Degeneration
Paralysis and other neurological conditions throughout the body can develop as the result of any number of conditions ranging from trauma to certain degenerative neurological conditions and can affect any number of areas ranging from the entire body to specific regions (such as the left or right half) or even simply specific appendages (such as fingers, toes, etc.). These conditions can be highly debilitating for many people and, up until recent years, if they were developed sometime in their life little could possibly be done to assist the person in regards to restoring lost functionality.
Because of the limited number of treatment options and the body’s natural difficulty in repairing damaged nerve cells paralysis has been a particularly strong focus for stem cell research over the years, especially following the successful treatment of a number of patients with nerve damage using “re-grown” cell structures cultured from stem cells in Shanghai, China. While results have been varied depending on the particular cause of the paralysis in the patient stem cell treatments have proven particularly effective in handling cases dealing with trauma, especially when allowed to be administered shortly after the trauma has been received.
Tests in Texas have proven that utilizing a modified version of adult stem cells harvested from a patient’s thigh bone marrow and specialized to target and regenerate damaged brain tissue have been able to return virtually all function that would be lost otherwise. Using this as a basis researchers have then turned to preemptive treatments of many developing neurological diseases, utilizing stem cells in the hopes of preventing conditions such as Parkinson’s, Alzheimer’s, Multiple Sclerosis and any number of other conditions affecting otherwise vulnerable brain tissue.
Currently no effective stem cell treatment is available for any chronically developing diseases that can be considered reliable for regular clinical usage, however with each passing year new developments are emerging that when coupled with other medicines and treatment methods are coming closer and closer to an effective long term solution. As for now the difficult nature presented by cases where neurological degeneration is not caused by trauma are proving particularly challenging to bypass due to the fact that any neurological regeneration instigated by stem cells will merely work to abate certain symptoms of development and will not, in fact, address the base line problem that is affecting the patient in the first place until further studies can be done that will allow doctors to target the cause in particular.
Why Use Stem Cells
Stem cells have been a hot topic in the medical industry in recent years, though for some people the question still exists as to why they are such an important issue in the first place. The primary reason for this lies in the base value stem cells have to our bodies as objects that can regenerate tissue and allow our body to repair itself in conditions that it otherwise cannot recover from.
With the multitude of tissues that exist within our bodies that have developed and specialized to one particular purpose many of these have lost the ability to actively repair themselves if damaged in order to return to virtually the same state that they existed in prior to the damage occurring while others have remained proficient at it. Skin cells, for instance, have retained this ability to a high degree and can conduct extensive repair procedures along with bone marrow cells that allow our bones to mend and re-grow. Nerve and cartilage cells, on the other hand, have nearly completely lost this ability due to the fact that they have needed to specialize into highly durable and difficult to alter forms in order to allow our body to function properly.
With the advent of stem cell research scientists have begun to allow two separate benefits to emerge that can benefit our bodies: the supplementing of our body’s natural repair functions in regards to tissue it can normally repair and avoid troublesome scar tissue and avoid cases where trauma may be too severe for our body’s natural regenerative capabilities to be adequate as well as the regeneration of certain cellular structures that otherwise cannot repair themselves due to their high level of differentiation and specialization. This effectively means that severe trauma to areas such as our skin or bones can potentially be reversed and allow the tissue to return to a near perfect pre-trauma state while at the same time allowing things such as nerve damage to no longer be an incurable debilitating issue.
Of course stem cells do come with their own risks associated with them along with many ethical issues, particularly in regards to the highly useful yet ethically questionable fetal stem cells that can be effectively used to repair virtually any system, yet the benefits gained from them are strong enough to make a solid argument in medical communities around the world and as of today they have been successfully used to help thousands of patients avoid otherwise debilitating damage that would have been untreatable just a few short years ago.
Stem cells ligament damage
Ligament damage (including ruptured or otherwise damaged tendons) has long been a concern for many medical staff for a number of reasons, primarily due to the fact that while most ligaments can be reattached or repaired in some way to return functionality to an individual they may not necessarily be able to return 100% usability to a damaged area. This is particularly true for highly sensitive areas such as fingers where repair of severed tendons commonly results in some partial loss of motor functions, even if done at a young age with an individual given plenty of time to recover.
With this in mind many researchers have turned to stem cell research – particularly research into adult stem cells that can be extracted from bone marrow – as a viable alternative to other commonly highly invasive and potentially damaging surgical procedures. The reason for this focus lies in the fact that stem cells gathered from bone marrow and modified slightly to regenerate specified tissues have a number of advantages that are unavailable in many other medical procedures, namely the fact that they come from the patient’s own body and therefore have virtually no risk of being rejected as well as the fact that they can work to actively form cellular bonds between two damaged ligaments that would otherwise only be able to be achieved through extensive surgical reattachment and the loss of some usable ligament in the process.
While advancements have been made in this regard there are still a number of concerns related to these developments, however. One of the largest issues related to this form of treatment lies in the fact that the high tensile demand of ligaments means any weak cellular bonds could easily be broken again should they not regenerate properly, resulting in further tissue damage. Additionally modified adult stem cells may not be able to adapt fully to the desired cellular construct, meaning that harvested and modified stem cells from the patient’s own body may not be sufficiently capable of regenerating the tissue effectively enough to be a viable treatment.
Nevertheless continued research into this method has shown many promising results, with similar research being cone into cartilage and other soft tissue regeneration also potentially aiding in this regard through the development of various regenerative techniques using both modified stem cells and conventional medical treatment. Current medical treatments for ligament damage involving stem cells are being carried out in medical institutions throughout the world with particular interest in Texas and London with promising success rates, helping to drive even further interest into these areas from both the private and public sectors.
Stem Cells Cloning
The ability to clone a particular cell, tissue, organ or even an entire body has a tremendous potential in the medical world in terms of what it can mean in terms of the development of a treatment or cure for any number of diseases and other ailments that individuals face around the world. Nevertheless while this may have a number of positive benefits attributed to it there are also a large number of ethical concerns related to cloning using stem cells that are preventing it from becoming a mainstream treatment option.
The primary reason for the ethical concerns related to stem cell cloning lies in the process of how the cloning occurs. As cells are driven by deoxyribonucleic acid (DNA) encoded within the central nucleus of the cell this means that, for a cell to divide and develop into an intended biological structure, an original cell must have its DNA removed and replaced with the target DNA – in computer terms, removing the entire hard disk and replacing it with a new one so you can start fresh. This forces the cell to replicate and follow the target DNA structure rather than its initially intended replication chain.
In order to ensure that the cell has the greatest replication ability as well the cell must be harvested and modified in as early of the cell’s replication stage as possible. For this reason newly developing embryonic cells are the most viable as they contain the potential to be “omnipotent” or develop into any cellular structure, while more differentiated cells (such as those taken from umbilical cord fluids) are already partially differentiated and therefore cannot be used to fully clone anything from an organ to an entire creature.
Because of the underlying benefit – and indeed necessity in most cases – of utilizing embryonic stem cells for treatment purposes little work has been done into this particular venue as any experiments or treatments using such cells would effectively be terminating any developing life. Nevertheless research is still being done on more differentiated “adult stem cells” that can be harvested from fully grown individuals with little to no harm to the person in order to generate treatments and recent advancements in this regard have proven highly promising in many regenerative treatments that can be used for a number of purposes. Still, full tissue or organ cloning using adult stem cells is proving difficult due to the differentiation needs and may prove a medical impossibility after all.
Stem Cells Limb Repair
Extensive limb damage to the point where amputation was the only solution has long been a problem for many medical professionals throughout the world, with crushed limbs in particular posing the greatest risk due to the fact that the bone can easily be damaged well beyond its own natural ability to repair itself.
Such was the case in England up until recently, where a new technique creating a “stem cell glue” has enabled a patient with a crushed leg to not only save his leg from amputation but be well on the way to making a full recovery, with a 100% return in leg functionality expected a mere 18 months after the initial treatment commenced.
The “glue” comes as a combination of a medical paste known as Cartifill and stem cells harvested from bone marrow extracted from the patient’s own hip. By combining the two substances and then applying it to the bone fragments within the damaged leg (having a total of 5 breaks and one compound fracture near the ankle after a boulder fell on the leg in a rock climbing accident) the fragments were then readjusted within the leg and held in place for 6 months with an external metal clamp in order to allow them to take hold. 6 months after the paste was applied and the cage removed the patient was able to support his entire body weight on the damaged leg, and is expected to be able to run on it one year after treatment once the bone has finished mending itself.
The paste Cartifill was originally designed by South Korean professor Seok Jung Kim and was intended at first to be a part of a cartilage replacement procedure wherein adult stem cells are mixed with the paste and then used to induce regeneration of damaged cartilage, particularly in knees. Thus far the paste has shown a number of successes in treating these cases as well, with roughly 80% of all patients undergoing Certifill stem cell treatment for knee repair reporting successful recoveries.
Further studies are currently being conducted in the UK with Professor Kim working to support other uses of the Cartifill solution assist with limb damage, potentially even assisting with the re-attaching of severed limbs by providing much needed support in reconnecting damaged muscle, bone and nerve tissue that may be damaged during the severing process. Current treatments utilizing this stem cell method are also relatively inexpensive, costing a few hundred Pounds at most, making it a highly affordable medical solution for many injured individuals.
Stem Cells Neuropathy
Neuropathy is an unfortunately relatively common issue that many people around the world face as a result of a number of different factors ranging from trauma to disease side effects. Regardless of the specific cause, however, the result is the same – a failing of proper neurological processes that can cause numbness, lack of responsiveness and for some people even complete paralysis.
Thankfully research is being done into a number of different processes that can help combat this ailment and bring about an effective treatment – or even complete cure – for many people that have experienced this symptom in the past or are suffering from it now. Each of these focuses on treating the direct cause of the neuropathy, not the symptom itself, and for many individuals preliminary research has already shown great progress.
One of the most common forms of neuropathy for many people, direct brain trauma (even minute) is being explored by stem cell researchers around the world as a prime candidate for initial test treatments as well progressive treatments for those having already been afflicted. Focusing on utilizing adult stem cells found within bone marrow (commonly extracted from the hip of a patient) and programming them to target specific neural pathways in the brain, initial reports have shown surprisingly optimistic results for many people by working to rebuilt neural pathways and prevent excessive damage from cascading into other regions – particularly if the treatments can be applied soon after the trauma is received.
Initial treatments are already currently under way at hospitals in some locations globally, with particular interest on children head traumas suffered in Texas. The results have shown a treatment of adult semi-differentiated stem cells can restore necessary brain pathways that would otherwise cause long-term neurological damage (with neuropathy being only one possible outcome) and prevent further damage from swelling from occurring.
For neuropathy caused by other chronic diseases such as diabetes treatments are further being explored in this regard as well. In terms of diabetes, as one example, research is being done on utilizing adult stem cells to stimulate insulin production within the pancreas and thus allow for the progressive damage to be halted before it gets worse. Existing damage could then be focused on with additional stem cell focus in order to re-grow damaged synaptic responses.
While neuropathy is difficult to focus on in particular due to the varied nature of it causes one thing is certain: advances in stem cell development and application are proving beneficial in all areas, and for many sufferers looking for help a treatment may soon be available in a medical center near you if it is not available already.
Stem Cells Brain Cancer
Brain tumors have been a difficult ailment to cure for many years due to their tedious position within bodies and the high possibility of damage to be done to the surrounding tissue that could easily result in further damage or even death during the treatment process. Further, targeting the specific causes of the cancer for treatment have proven particularly difficult due to the limited ability to effectively analyze the specific causes of the tumors in the past.
Recent studies, however, have shown some progress in the way that doctors have been able to identify and subsequently develop treatments to hopefully treat and even cure many tumor developments. Through the process of tracking specific stem cells and their growth patterns it has been determined that brain tumors are actually the result of malfunctioning stem cells located near blood vessels within the brain to utilize the body’s resources to multiply exponentially and damage surrounding cells – a process that previously hadn’t been considered as a possibility due to the fact that doctors believed tumors to consist of one particular cell line rather than a collection of different cells.
This targeting of specific stem cells has allowed doctors to develop treatments to hone in on the blood stem cells carrying the cancer in order to kill tumor development at its source. Current treatment phases have even begun moving out of laboratory testing and have begun to be done on human beings, with children suffering from brain cancer as a primary focus group due to their inherent higher cellular regenerative abilities.
Should this process prove successful it could potentially mean a number of different treatments could also be looked at for other cancerous developments as well. Blood and bone marrow cancers, for instance, could have specific malfunctioning stem cells emanating in the blood targeted both chemically by medicines and through other treatment methods to effectively eliminate trouble spots before they can masticate to surrounding tissue and thus inflict damage that most conventional cancer treatments will be unable to target.
Should any damage be done to the brain as well from developing cancers before they are treated other uses of stem cells from healthy parts of the body (such as unaffected bone marrow) are also being explored for use as regenerative sources for brain tissue, thus potentially allowing a restoration of damaged locations that was previously considered impossible even up to just a few years prior to now.