Poster Presentation 2014 Cutaneous Biology Meeting

Evaluation of keratinocytes migration on integrin specific artificial ECM protein substrates (#39)

MONICA SURYANA TJIN 1 , ALVIN WEN CHOONG CHUA 2 , SENG TEIK LEE 3 , EILEEN FONG 1
  1. School of Materials Science and Engineering, Nanyang Technological University, Singapore
  2. Skin Bank Unit, c/o Department of Plastic Reconstructive & Aesthetic Surgery, Singapore General Hospital, Singapore
  3. Department of Plastic Reconstructive & Aesthetic Surgery, Singapore General Hospital, Singapore

Epithelial cell migration is a crucial event in wound healing. Upon wounding, wound edge epidermal keratinocytes become highly motile and laminin-5 is known to play a major role in keratinocytes motility. Integrin alpha3beta1 has been known as one of the major receptor for laminin-5, yet in vitro evidence of the role of alpha3beta1 integrin in keratinocyte motility is controversial. Some studies have reported that integrin alpha3beta1 promotes keratinocytes migration [1-3], while others reported the opposite [4-6].

To address the role of alpha3beta1 integrin in epithelial cell migration and wound healing, we generated an artificial extracellular matrix (aECM) protein containing cell binding domain derived from Laminin-5. PPFLMLLKGSTR, a motif in the LG3 domain of laminin-5 alpha3 chain, has been shown as a major site for integrin alpha3beta1 binding.  In accordance to the previous reports [7-8], we found that keratinocytes attachment to this aECM protein is specific to alpha3 integrin. Single cell migration assay revealed that keratinocytes on aECM protein exhibit less elongated, fan-shaped cell morphology, and move with a significantly slower speed and less persistence compared to native LN. We showed that alpha3 antibody blocking further reduced speed and persistence on both native LN and aECM. Similar trend was observed on wound healing assay, whereby the wound closure on native LN is nearly two fold faster compared to aECM protein, accounting on its lower cell speed and persistence. Our findings suggest that alpha3 integrin may not be the key determinant in promoting keratinocytes motility and persistence. 

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