Epidermal-specific deletion of CD44 reveals a function in keratinocytes in response to mechanical stress.
CD44, a large family of transmembrane glycoproteins, plays decisive roles in physiological and pathological conditions. CD44 isoforms are involved in several signaling pathways essential for life such as growth factor-induced signaling by EGF, HGF or VEGF. CD44 is also the main hyaluronan (HA) receptor and as such is involved in HA-dependent processes. To allow a genetic dissection of CD44 functions in homeostasis and disease, we generated a Cd44 floxed allele allowing tissue- and time-specific inactivation of all CD44 isoforms in vivo. As a proof of principle, we inactivated Cd44 in the skin epidermis using the K14Cre allele. Although the skin of such Cd44Δkermutants appeared morphologically normal, epidermal stiffness was reduced, wound healing delayed and TPA induced epidermal thickening decreased. These phenotypes might be caused by cell autonomous defects in differentiation and HA production as well as impaired adhesion and migration on HA by Cd44Δkerkeratinocytes. These findings support the usefulness of the conditional Cd44 allele in unraveling essential physiological and pathological functions of CD44 isoforms.
Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Karlsruhe, Germany.
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M
Shatirishvili
University of Heidelberg, Institute of Physical Chemistry, Heidelberg, Germany.
A S
AS
Burk
Karlsruhe Institute of Technology, DFG-Center for Functional Nanostructures, Karlsruhe, Germany.
C M
CM
Franz
Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Karlsruhe, Germany.
G
G
Pace
Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Karlsruhe, Germany.
T
T
Kastilan
Heidelberg University Hospital, Institute of Pathology, Heidelberg, Germany.
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K
Breuhahn
Laboratory for Immunological and Molecular Cancer Research, Third Medical Department with Hematology, Medical Oncology, Hemostaseology, Infectious Diseases, and Rheumatology, Oncologic Center, Paracelsus Medical University, Salzburg, Austria.
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E
Hinterseer
Institut Clinique de la Souris Illkirch, Illkirch, France.
A
A
Dierich
Spanish National Cancer Centre, Genes Development and Disease Group, Cancer Cell Biology Programme, Madrid, Spain.
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L
Bakiri
Spanish National Cancer Centre, Genes Development and Disease Group, Cancer Cell Biology Programme, Madrid, Spain.
E F
EF
Wagner
Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Karlsruhe, Germany.
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H
Ponta
Laboratory for Immunological and Molecular Cancer Research, Third Medical Department with Hematology, Medical Oncology, Hemostaseology, Infectious Diseases, and Rheumatology, Oncologic Center, Paracelsus Medical University, Salzburg, Austria.
T N
TN
Hartmann
University of Heidelberg, Institute of Physical Chemistry, Heidelberg, Germany.|Institute for Integrated Cell-Material Sciences (WPI iCeMS), Kyoto University, Kyoto 606-8501, Japan.
M
M
Tanaka
Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Karlsruhe, Germany.
V
V
Orian-Rousseau
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004817:Epidermis / Q000378:metabolism*; D017353:Gene Deletion; D006706:Homeostasis / Q000187:drug effects; D018960:Hyaluronan Receptors / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000494:pharmacology; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism*; D007633:Keratins / Q000378:metabolism; D018345:Mice, Knockout; D009928:Organ Specificity / Q000187:drug effects; D012867:Skin / Q000378:metabolism; D013314:Stress, Mechanical; D014945:Wound Healing / Q000187:drug effects
D018960:Hyaluronan Receptors; D007633:Keratins; D006820:Hyaluronic Acid