Skin Cells Cure Sickling in Red Blood Cells

Imagine if the cells of the largest organ in humans; skin cells could treat pateints with sickle cell anemia. This is no longer a possibility but a reality!

Sickle cell anemia is an inherited blood disorder that causes the body to produce abnormally shaped red blood cells. People with this disease are born with two sickle cell genes, one inherited from each parent. It is caused by the substitutuion of an amino acid in the protein sequence of hemoglobin. As a result, normally round blood cells become shaped like a crescent or sickle. These cells have short life spans compared to normal blood cell which causes the person to be anemic. Also, due to the abnormal shape, sickle cells often block blood vessels and thus reduce blood flow. This causes severe pain and various complications due to organ damage.

In a study published in Science by AAAS in 2007, scientists found significant evidence that supported the use of skin cells to restore the function of sickled red blood cells. In this study, three groups of mice were examined; control (normal mice), untreated (mice with sickle cell anemia but no treatment) and treated (mice with sickle cell anemia and treatment). Mice injected with humainsed sickle globin genes developed typical disease symptoms such as "severe anemia, urine concentration defects and overall poor health". From these mice, skin cells  from the tail were reprogrammed with gene therapy and cloned into induced pluripotent stem cells (iPS). iPS cells are genetically and developmentally similar to embryonic cells, wich are able to turn into all cell types. The iPS cells correct the sickle cell mutation by specific gene targeting. The genetically corrected iPS cells are then transplanted into sickle cell affected mice.

According to the results, the mice treated with iPS cells recovered 8 weeks after the transplant. The results of blood smears showed that treated mice had significanly lower amount of elongated or sickled cells compared to the untreated mice. Also, the blood count tests showed that treated mice had noticeable increases in red blood cell count and hemoglobin. There was also a definite reduction in sickle cell hemoglobin protein in treated mice, 4 to 8 weeks after transplantation.

Using iPS cells as a means of treatment has various advantages listed as follows:

1. iPS cells able to repair genetic defects

2. No requirement for unmatched transplanted cells (skin cells used from same person who is infected and so no compatibility problems)

3. Ability to use and convert iPS cells into any cell type for therapy

In conclusion, the treatment of sickle cell anemia by iPS cells of mouse skin cells is definitely a promising advancement towards curing sickled red blood cells in humans. Further research in this area is currently taking place, with a specific focus on reprogramming techniques in an attempt to reduce risks and developing reliable protocols for human iPS cells.

Reference:

2007, Hanna, et al. "Treatment of Sickle Cell Anemia Mouse Model with IPS cells generated from Autologous Skin", Science, American Association for the Advancement of Science, New York, Vol 318, pp1920-1923 < http://www.sciencemag.org/cgi/content/full/318/5858/1920 >

DOI: 10.1126/science.1152092

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Student Name:  Manal Masood

Student Number: 42028349