Induced pluripotent stem cells offer new approach to therapy in thalassemia and sickle cell anemia and option in prenatal diagnosis in genetic diseases

Abstract

The innovation of reprogramming somatic cells to induced pluripotent stem cells provides a possible new approach to treat beta-thalassemia and other genetic diseases such as sickle cell anemia. Induced pluripotent stem (iPS) cells can be made from these patients' somatic cells and the mutation in the beta-globin gene corrected by gene targeting, and the cells differentiated into hematopoietic cells to be returned to the patient. In this study, we reprogrammed the skin fibroblasts of a patient with homozygous beta(0) thalassemia into iPS cells, and showed that the iPS cells could be differentiated into hematopoietic cells that synthesized hemoglobin. Prenatal diagnosis and selective abortion have been effective in decreasing the number of beta-thalassemia births in some countries that have instituted carrier screening and genetic counseling. To make use of the cells from the amniotic fluid or chorionic villus sampling that are used for prenatal diagnosis, we also showed that these cells could be reprogrammed into iPS cells. This raises the possibility of providing a new option following prenatal diagnosis of a fetus affected by a severe illness. Currently, the parents would choose either to terminate the pregnancy or continue it and take care of the sick child after birth. The cells for prenatal diagnosis can be converted into iPS cells for treatment in the perinatal periods. Early treatment has the advantage of requiring much fewer cells than adult treatment, and can also prevent organ damage in those diseases in which damage can begin in utero or at an early age.

Fig. 1.

iPS cell colonies reprogrammed with 3 factors (3sy) or 4 factors (4sy) from the skin fibroblasts of a patient with homozygous β–thalassemia (β-thal) compared with hESC colonies (hES). They were stained for alkaline phosphatase (AP, Inset) and ES cell markers Nanog, SSEA3, SSEA4, Tra-1–60, and Tra-1–81.

Fig. 2.

Sequence analysis (A) and karyotype (B) of iPS cells reprogrammed from fibroblasts of the patient with β-thalassemia.

Fig. 3.

Photomicrographs of H&E stain of teratoma formed in NOD-SCID mice after injection of iPS cells from the patient with β-thalassemia patient shows (A) heterogeneous tissue under low power (magnification ×4), (B) respiratory epithelium, (C) bone, and (D) neural tissues (magnification ×20).

Fig. 4.

Differentiation of iPS cells into hematopoietic cells. (Left) Hematopoietic colonies (magnification ×4); (Middle) Giemsa stain showing hemoglobinization of some of the cells; (Right) Superimposition of DAPI and anti-hemoglobin F antibody stains (magnification ×40).

Fig. 5.

Human ES cells compared with iPS cell colonies reprogrammed from cells from AF and CVS.

Fig. 6.

Embryoid body-mediated differentiation of iPS cells derived from amniotic fluid cells. (A) Photomicrograph of differentiated iPS cells on day 16 (magnification ×4) and immuno-stained with (B) α-smooth muscle actin, (C) βIII-tubulin, and (D) α-fetoprotein (magnification ×20).