Karen Echeverri, PhD

Research Techniques:

Axolotl transgenesis, in vivo fluorescence microscopy, 2D and 3D culturing of cell lines and primary cells.

Research Interests

Throughout human life, many cells such as hair follicles and certain tissues such as liver can be continuously replaced to maintain tissue integrity in response to normal, daily wear and tear. However, the human response to more serious tissue damage, such as acute damage to limbs or to the spinal cord, is limited to relatively simple wound healing, whereby collagenous scar tissue fills the injury site, assuring the tissue’s structural integrity but often resulting in a debilitating loss of functional activity. While humans do exhibit some very limited regenerative capacity (e.g. finger tips), other vertebrates exhibit sometimes astonishing regenerative ability.

Salamanders show the highest diversity in being able to regenerate limbs, tail, heart, eyes and jaw

Our aim is to understand at the molecular and cellular level how an axolotl spinal cord can functionally repair after injury and why mammals cannot. To this end we have used transcriptional profiling to identify key differences at the miRNA level between axolotl and rat after spinal cord injury. In particular we are focusing on the differences between the rostral and caudal sides of the injury site and how the axolotl creates a permissive environment for axonal regrowth while mammals do not. We are focusing not just on the neuronal cells but also on the contribution and interaction of the other cells especially endothelial cells and skin to this repair process.

In addition to understanding spinal cord repair we are also interested in elucidating conserved pathways used for all regenerative processes like limbs, heart, pancreas etc as well as those which tell cells at a cut surface what and how much needs to be regenerated.

Selected Publications

Sehm T, Sachse, C , Frenzel, C and Echeverri K. miR-196 is an essential early-stage regulator of tail regeneration, upstream of key spinal cord patterning events. Dev Biol. 2009 Oct 15;334(2):468-80. Epub 2009 Aug 13

Echeverri, K and AC Oates. 2007.Suppressor of Hairless coordinates bilateral cyclic gene expression during somitogenesis and plays an important role in left-right patterning of the vertebrate embryo. Dev. Biol. Jan 15;301(2):388-403

Echeverri, K and EM Tanaka. 2005. Proximodistal Patterning during Limb Regeneration. Dev. Biol. 279(2):391-401.

Echeverri, K. and EM Tanaka. 2002. Ectoderm to Mesoderm Lineage Switching during Axolotl Tail Regeneration.Science  298: 1993-1996

Echeverri K, Tanaka EM. Mechanisms of muscle dedifferentiation during regeneration.Semin Cell Dev Biol. 2002 Oct;13(5):353-60. Review.

Echeverri, K., Clarke, JD and EM Tanaka. 2001. In vivo imaging indicates muscle fiber dedifferentiation is a major contributor to the regenerating tail blastema.Dev. Biol. 236 (1):151-64.