Characterization of mesenchymal stem cells isolated from Wharton’s jelly of the human umbilical cord

Abstract

Abstract Background Isolation of post-partum umbilical cord Wharton’s jelly stem cells has gained attention as an alternative source of the bone marrow. Because easy isolation, lack of ethical concerns, and the presence of both embryonic and adult stem cells have made them a valuable source for use in therapeutic applications and regenerative medicine. The study utilized a modified protocol using in-house human pooled cord blood serum for isolation and expansion of the mesenchymal stem cells obtained from the human umbilical cord Wharton’s jelly. Cell proliferation and population doubling time and tri-lineage differentiation were assessed, and the expressions of mesenchymal cell surface markers CD44, CD90, CD105, and CD34 were assessed by flow cytometry and RT-PCR. The genetic stability of the isolated cells was assessed by chromosomal karyotype. Results The isolated cells displayed fibroblastic-like morphology and tri-lineage differentiation into adipocyte, chondrocyte, and osteocyte. The isolated cells maintained the proliferative competence with a doubling time ranged from 38 to 42h and corresponded well with the standard positive and negative molecular markers (CD44+, CD90+, CD 105+, and CD34−). Cell senescence occurred at the later passage of the cells (P15) affecting, about 25% of the population. Metaphases spread of the cells showed normal diploid karyotypes, with typical chromosomal plates indicating genetic stability of the isolated cells. Conclusion The primary cultures exhibited success in isolating the umbilical cord Wharton’s jelly mesenchymal stem cells, which maintained their tri-lineage differentiation potential, phenotypes and karyotype characteristics on further passage and expansion.

Keywords

• Karyotype
• Wharton’s jelly
• Stem cells