#scnt

Human Genetic Engineering: Goals & Means

Image Courtesy: link: http://www.biology-questions-and-answers.com/genetic-engineering.html author: biology-questions-and-… description: Genetic Engineering Definition C O N T E N T S: KEY TOPICS Behavioral traits often identified as potential targets for modification through human genetic engineering include intelligence, clinical depression, schizophrenia, alcoholism, sexual behavior (and…

The Finding:

Published on April 28th, 2014 in the prestigious scientific journal Nature, a team of scientists at the New York Stem Cell Foundation and Columbia University Medical Center had finally overcome the final hurdle in making personalized stem cells that can be used to develop personalized cell therapies. They had created the first diploid embyonic stem cell line that is specific to a disease. In this case, that disease is Type 1 Diabetes. Diploid means that there are two sets of chromosomes in the stem cell, the normal number in human cells. The embryonic stem cells were created from two different donors, a healthy male newborn and an adult with type 1 diabetes. Now these newly created embyonic stem cells can be differentiated into insulin-producing beta cells, the cell type lost in type 1 diabtes. 

Why is this Important:

As quoted in a pressed release, one the head researchers, Dr. Egli, stated, ""By reprograming cells to a pluripotent state and making beta cells, we are now one step close to being able to treat diabetic patients with their own insulin-producing cells."  Patients with type 1 diabetes lack insulin-producing beta cells. Insulin is a peptide hormon that is central to regulating carbohydrate and fat metabolism in the body. It causes cells to absorb glucose from the blood. Hence, type 1 diabetes patients are insulin deficient and have high blood sugar levels. Therefore, producing insulin-producing beta cells from stem cells for transplantation holds promise as a treatment and potential cure for type 1 diabetes. Because the stem cells are made using a patient's own skin cells, the beta cells for replacement therapy would be autologous, or from the patient, matching the patient's DNA, avoiding the risk of the patient's bod rejecting the transplantation.

How Did They Do It:

To put it simply, they derived these embryonic stem cells by adding the nuclei of adult of skin cells to unfertilized donor oocytes (egg cells) . This process is called somatic cell nuclear transfer.  

Future Steps & Applications:

This is the first report of the derivation of diploid pluripotent stem cells from a patient and from a human after birth. Generating patient-specific or autologous beta cells is only the first step in developing a complete cell replacement therapy for type 1 diabees. In type 1 diabetes, the body's imune system attacks its own beta cells. Hence, more work needs to be done to coem up with strategies to protect and prevent these therapeutic beta cells from attack by the immune system.

The technique described in the report can also be translated for use in the development of personalized autologous cell therapies for many other diseases and conditions including Parkinson's disease, macular degeneration, multiple sclerosis, and liver diseases and for replacing or repairing damaged bones.

Somatic cell nuclear transfer (SCNT) is a technique for cloning. The nucleus is removed from a healthy egg. This egg becomes the host for a nucleus that is transplanted from another cell, such as a skin cell. The resulting embryo can be used to generate embryonic stem cells with a genetic match to the nucleus donor (therapeutic cloning), or can be implanted into a surrogate mother to create a cloned individual, such as Dolly the sheep (reproductive cloning).

Human Clone Embryonic Stem Cell Lines - Business Insider

Researchers announced Wednesday, May 15, in the journal Cell that they've been able to make stable colonies of embryonic stem cells by injecting the DNA from 'adult' human cells into a human egg cell emptied out of its genetic material.

"Our finding offers new ways of generating stem cells for patients with dysfunctional or damaged tissues and organs," study researcher Shoukhrat Mitalipov of Oregon Health & Science University, said in a press release. "Such stem cells can regenerate and replace those damaged cells and tissues and alleviate diseases that affect millions of people."

This technique they used to make these stem cells is called somatic cell nuclear transfer, and is the same technique used to clone animals, like Dolly the sheep.

To put it in very simplified terms: the researchers first harvest a human egg from a woman's ovaries and completely remove her genetic material from the egg. Then, they take a human skin cell and insert it into the egg using an inactivated virus which fuses the two cells. The embryo that grows from this would be a genetic copy of the person that donated the cell.