Celulas Madre

Medicina Universitaria 2007;9(36):130~40

Articulo de revision
Celulas madre
Jose Carlos Jaime Perez,* Idalia Garza Veioz,** Rocio Ortiz Lopez*

RESUMEN
Las celulas madre tienen la capacidad de autorenovarse y diferenciarse para producir diversos tipos de c6lu!as especializadas. Las c6lulas
madre se clasifican por su potencial de diferenciacion en totipotenciales, pluripotenciales ymultipotenclales, y segun el tejido de origen
en embrionarias o adultas. Estas celulas generan gran interes por los diferentes modelos de diferenciaci6n a los que pueden conducirse;
desde el modelo convencional (ceiula madre-celula hija), hasta procesos de transdiferenciacion y desdiferenciacion celular. Estos modelos
se aplican para entender el fenomeno de plasticidad. Se denomina plasticidad delas celulas madre a la capacidad de generar diferentes
grupos celulares a los de su tejido de origen, como las de las celulas madre hematopoyelicas, que forman hepatocitos y miocitos en
condiciones controladas. En la actualidad existen controversias eticas, ya que los estudios en celulas madre se realizan a partir de 6vulos
donados en los centros de fertilizacion humana; sin embargo, puedenobtenerse celulas madre con caracteristicas pluripotenciales de
otras fuentes, como las de! liquido amniotico. La legislacion internacional, respecto de la obtencidn de celulas madre es heterog^nea y
divergente. mientras que la legislacion nacional resulta limitada ante los retos que plantea la investigacion cientifica.
Palabras clave; celulas madre, diferenciacion celular, plasticidad, replicacioncelular, terapia celular, transplante hematopoy6tico.

ABSTRACT
Stem cells are defined by their self-renewal capacity and their ability to generate diverse kinds of specialized progeny. Stem cells can be
classified by their differentiation potential as totipotent, pluripotent, or multipotent, and by their tissue of origin in embryonic or adult stem
cells. A great deal of interest has risenregarding their distinct differentiation models, from the conventional straightforward mother stem
cell-daughter cell, to the considerably more complex transdifferentiation and undifferentiation models. These models are currently being
applied to understand the phenomenon of cell plasticity that characterizes these cells. Stem cell plasticity accounts for the capacity to
generate cells typesdifferent from their original tissue, a good example being the hematopoietic stem cells, which can give origin to hepatocytes and myocytes under highly regulated conditions. There are challenges and controversies regarding diverse aspects of research
in stem cell plasticity studies, as a great deal of them are performed on donated ova from human fertility centers, leading to heated ethic
argumentsthat require being dealt with in order to further improve stem cell research. Currently, it is possible to obtain pluripotent stem
cells from sources other than human embryos, for example the amniotic fluid. New and spectacular developments in stem cell therapy and
regenerative medicine are continuously being investigated. International legislation regarding manipulation and research on stemcells is
heterogeneous and frequently divergent, whereas national laws are limited in their capacity to deal with the evolving challenges in these
research and therapeutic field.
Key Words: Stem cell, cellular differentiation, plasticity, cellular replication, cellular therapy, hematopoietic transplant.

*
**

Servicio de Hematologia,
Departamento de Bioquimica.
Facultad de Medicina yHospital Universitario Dr. Jos6 Eleuterio
Gonzalez de la UANL.

Correspondencia: Dr, Jos6 Carlos Jaime P6rez. Servicio de Hematologia, Edificio Dr. Rodrigo Barragan Viliarreal, 2° piso, Facultad
de Medicina y Hospital Universitario Dr. Jose Eleuterio Gonzalez de
la UANL. Ave, Francisco I. Madero y Gonzalitos s/n, colonia Mitras
Centro. CP 64460, Monterrey, Nuevo Leon, Mexico,
Tel./fax:...