Center for Muscle Research

Westerman Group

The Westerman group has been characterizing a unique type of muscle stem cell, referred to as myosphere cells. These cells form non-adherent spheres in culture and canmaintained in a primitive ‘pre-myogenic’ state for long periods of time.

In characterizing these cells we became interested in adhesion molecules that maintain these cells as spheres in culture. Our most recent research involves interaction of GPI anchored protein Sca-1 and adhesion molecule αVβ3 integrin. We discovered that cells expressing Sca-1 interact adhesively with αVβ3 integrin and that this adhesiveness is enhanced when Sca-1 and β3 integrin are expressed within the same cell, indicating these molecules interact by both trans and cis mechanisms. The importance of this interaction is that the activation of αVβ3 integrin is involved in the repair and remodeling of injured tissues, indicating that perhaps purpose of Sca-1 expression by stem cells is to aid in the response to injury. In addition, the Westerman lab maintains an interest in tissue engineering and collaborates with the Tissue Engineering Laboratory (Dr. Charles Vacanti’s group). Our most recent tissue engineering project involves studying cell and polymer combinations to produce a more stable tissue engineered ear. This research has been supported by grants from NIAMS (KO1 AR052372-01) and Regenear.

Dr. Westerman is also the organizer of the Longwood Muscle Stem Cell Group, which is composed of 63 researchers from Brigham and Women’s Hospital, Children’s Hospital, Joslin Diabetes Center, Dana Farber Cancer Institute, Mass General, MIT, Boston University, Tufts, and the BBRI. This group meets once a month to present stem cell and muscle related research. If you interested in joining this group contact Karen Westerman at

Lab Members

  • Karen WestermanKaren Westerman, Ph.D.
  • Takeshi AobaTakeshi Aoba, M.D., Ph.D.
  • Siddharth RamshankarSiddharth Ramshankar, M.S.

Select Publications

  • Westerman KA, Ao Z, Cohen EA, Leboulch P., Design of a trans protease lentiviral packaging system that produces high titer virus. Retrovirology. 2007. 4:96.
  • Westerman KA, Penvose A, Yang Z, Allen PD, Vacanti CA., Adult muscle 'stem' cells can be sustained in culture as free-floating myospheres. Exp Cell Res. 2010. 316:1966-76.
  • Obokata H, Kojima K, Westerman K, Yamato M, Okano T, Tsuneda S, Vacanti CA., The potential of stem cells in adult tissues representative of the three germ layers. Tissue Eng Part A. 2011. 17:607-15.
  • Penvose, A. and Westerman, K., Sca-1 is involved in the adhesion of myosphere cells to αVβ3 integrin. Biology Open (2012) 1:839-847.