Hair-like Structures Formed by Umbilical Cord Stem Cells

Michael Detamore‘s laboratory at the University of Kansas Medical Center has used mesenchymal stem cells from connective tissue in human umbilical cord tissue to form structures that have some although not all features of human hair.

Human umbilical cord contains a unique connective tissue called “Wharton’s jelly.” Wharton’s jelly expands after birth to staunch bleeding from the umbilical veins and arteries. Within Wharton’s jelly is a mesenchymal stem cell population called Wharton’s Jelly Mesenchymal Stromal Cells or WJMSCs. Experiments in a variety of labs have shown that WJMSCs have differentiate into bone, cartilage, muscle, and neural cells. Recently, several labs have used three-dimensional culture systems to get WJMSCs to differentiate into tubular and endometrial cells.

Detamore and his co-workers used this three-dimensional culture system to differentiate WJMSCs into layered structures that expressed some of the genes associated with hair follicles and also looked like follicles. The cells formed small spheres of cells known as “spheroids.” Detamore and his colleagues showed that these spheroids can form bone, but during done differentiation, Detamore and the other workers in his lab noticed that the spheroids form protrusions that looked like hairs. See for yourself below.

Patterns of hair-like structures in DWJM. Hair-like structures were observed growing out of DWJM 2 weeks following WJMSC seeding and osteogenic induction. In phase-contrast microscopy pictures (A, B) taken during culture, hair-like structures were observed to grow under the outer layer of the DWJM and in some cases either successfully protruded through the outer layer (A) or just caused a protrusion of the outer layer of DWJM (B). Also, the hair-like structures were either straight (A, C–E) or coiled (B). The green arrows in picture (A) pointed to the outer layer covering DWJM. The hair-like structure caused the outer layer covering DWJM to appear lifted up. In this DWJM, 2 hair-like structures protruded through DWJM (red arrows) seen in (A, C–E). A second hair-like structure (red arrows) protruded through the outer layer of DWJM; however, this hair-like structure was surrounded by tissue material (E). In (F), multiple areas of protrusions noted (black arrows). In (C–E) pictures, material was visualized using Nikon SMX1500 dissecting microscope and pictures were taken using Optem DC50NN camera. Scale bars represent 100 μm.

The other side of the spheroid did form bone, but the hair-like structures did eventually form bone. There are specific genes that are expressed in hair follicles, and these can be used to determine if the projections are actually hair follicles. One of these genes, cytokeratin 19 or CK19, was expressed at pretty high levels in the hair follicles. Another hair-specific gene, CK15 was also expressed in the hair-like structures.

Are these real hair follicles? Probably not, but they seem to be on their way to making hair follicles. Furthermore, the production of these hair-like structures was rather easy. If WJMSCs could be used to make hair, then they might be useful for cosmetic procedures that replace lost hair follicles as a result of baldness.