The neural crest (NC) is a region of cells that forms in the earliest stages of development that is unique in many ways. The NC is composed of stem cells that complete vast migrations and differentiate into many completely different cell types. These cells are being researched due to their unique features and the fact that they end up forming many important regions of the fully developed body. The research of the migration and multipontency of neural crest cells could lead to breakthroughs in the understanding of how cancers metastasize and how many birth defects are caused or can be fixed.
Neural crest cells form in between the neural plate and the ectoderm. They are formed, or induced, by an exact combination of many signals (including bone morphogenic protein levels, Wnt levels, and notch signals). These signals begin the expression of specific transcription factors that differentiate the NC cells from those around them. It is still debated whether these NC cells have predestined roles in the body, or whether the signals they encounter during their migration determine how they end up. It appears that different NC cells have different levels of plasticity and multipotency.
What scientists have discovered about the migration of these cells is that it is done though many different means. They have noticed that the cells participate in many different mechanisms of migration such as contact-inhibition locomotion, chemotaxis, and cell sorting (Mayor & Theveneau, 2013). Contact inhibition locomotion (CIL) describes when two cells confront each other and consequently retract their protrusions and move in a different direction away from the other cell. The trend is clearly observable; however, the reasons behind it are not yet clear (Carmona-Fontaine et al., 2008). Essentially, when two NC cells meet, they repolarize and head in opposite directions. This does not match with the fact that NC cells also tend to migrate in large groups. It is thought that chemotaxis and co-attraction between the NC cells causes this discrepancy. Certain factors such as C3a are secreted that attract NC cells and cause them to follow the chemical. Finally, NC cells are “guided” by the extracellular matrix and by the cells sorting into groups with different levels of a chemical Eph/ephrin (Mayor & Theveneau, 2013).
The complex migration of NC cells is comparable to the migration of tumor cells in certain cancers (Mayor & Theveneau, 2013). Because there are so many parallels in the growths and development of the NC and the growth and development of many cancerous tumors, research done on the neural crest can aid cancer research (Zhang et al., 2014). Researchers are focusing on predicting NC movement in order to apply it to cancer metastasis patterns. NC cells are also being analyzed due to the fact that abnormal NC migration causes many birth defects such as cranio-facial defects, cardiac defects, pigmentation defects, hearing loss, and missing external ganglia (Mayor & Theveneau, 2013).
References:
Mayor R. & Theveneau E. (2013). The Neural Crest. The Company of Biologists’ Development, 140, 2247-2251. http://dx.doi.org/10.1242/dev.091751
Zhang D., Ighaniyan S., Stathopoulos L., Rollo B., Landman K., Hutson J. & Newgreen D. (2014). The Neural Crest: A Versatile Organ System. Birth Defects Research Part C: Embryo Today: Reviews, 102(3), 275-298. http://dx.doi.org/10.1002/bdrc.21081
Carmona-Fontaine C., Mattews H. K., Kuriyama S., Moreno M., Dunn G.A., Parsons M., Stern C.D., & Mayor R. (2008). Contact Inhibition of Locomotion in vivo Controls Neural Crest Directional Migration. Nature, 456(7224), 957-961. http://dx.doi.org/10.1038/nature07441
Neural crest cells form in between the neural plate and the ectoderm. They are formed, or induced, by an exact combination of many signals (including bone morphogenic protein levels, Wnt levels, and notch signals). These signals begin the expression of specific transcription factors that differentiate the NC cells from those around them. It is still debated whether these NC cells have predestined roles in the body, or whether the signals they encounter during their migration determine how they end up. It appears that different NC cells have different levels of plasticity and multipotency.
What scientists have discovered about the migration of these cells is that it is done though many different means. They have noticed that the cells participate in many different mechanisms of migration such as contact-inhibition locomotion, chemotaxis, and cell sorting (Mayor & Theveneau, 2013). Contact inhibition locomotion (CIL) describes when two cells confront each other and consequently retract their protrusions and move in a different direction away from the other cell. The trend is clearly observable; however, the reasons behind it are not yet clear (Carmona-Fontaine et al., 2008). Essentially, when two NC cells meet, they repolarize and head in opposite directions. This does not match with the fact that NC cells also tend to migrate in large groups. It is thought that chemotaxis and co-attraction between the NC cells causes this discrepancy. Certain factors such as C3a are secreted that attract NC cells and cause them to follow the chemical. Finally, NC cells are “guided” by the extracellular matrix and by the cells sorting into groups with different levels of a chemical Eph/ephrin (Mayor & Theveneau, 2013).
The complex migration of NC cells is comparable to the migration of tumor cells in certain cancers (Mayor & Theveneau, 2013). Because there are so many parallels in the growths and development of the NC and the growth and development of many cancerous tumors, research done on the neural crest can aid cancer research (Zhang et al., 2014). Researchers are focusing on predicting NC movement in order to apply it to cancer metastasis patterns. NC cells are also being analyzed due to the fact that abnormal NC migration causes many birth defects such as cranio-facial defects, cardiac defects, pigmentation defects, hearing loss, and missing external ganglia (Mayor & Theveneau, 2013).
References:
Mayor R. & Theveneau E. (2013). The Neural Crest. The Company of Biologists’ Development, 140, 2247-2251. http://dx.doi.org/10.1242/dev.091751
Zhang D., Ighaniyan S., Stathopoulos L., Rollo B., Landman K., Hutson J. & Newgreen D. (2014). The Neural Crest: A Versatile Organ System. Birth Defects Research Part C: Embryo Today: Reviews, 102(3), 275-298. http://dx.doi.org/10.1002/bdrc.21081
Carmona-Fontaine C., Mattews H. K., Kuriyama S., Moreno M., Dunn G.A., Parsons M., Stern C.D., & Mayor R. (2008). Contact Inhibition of Locomotion in vivo Controls Neural Crest Directional Migration. Nature, 456(7224), 957-961. http://dx.doi.org/10.1038/nature07441