The effect of pH in modulating skin cell behaviour.
BACKGROUND
Variations occur in the pH of cutaneous wounds which may affect wound closure, graft take and microbial infection rates.


OBJECTIVE
To determine how pH modulates cell behaviour in order to optimize wound care.


METHODS
The effects of pH on the attachment, proliferation and migration of keratinocytes and fibroblasts were investigated in vitro and in an ex vivo skin growth model. In addition, the effect of pH on keratinocyte differentiation as measured by the expression of cytokeratins 1 (K1) and K5 was studied.


RESULTS
We demonstrated that the optimal pH for both keratinocyte and fibroblast proliferation is between pH 7.2 and 8.3. The optimal pH for growth from ex vivo skin explants was pH 8.43 which correlates with a previously reported improvement in skin graft take at higher pHs. Expression of K1 was found to be elevated in keratinocytes at a low pH.


CONCLUSIONS
These results demonstrate that skin cells and explants proliferate and migrate at pHs higher than the physiological pH and that at lower pH keratinocytes express a differentiated keratinocyte phenotype. A better understanding of the responses of the cellular components of skin to fundamental physiological variables such as pH may help inform improved clinical wound care.
Blond McIndoe Research Foundation, Queen Victoria Hospital, East Grinstead, UK. justin.sharpe@blondmcindoe.com
J R
JR
Sharpe
K L
KL
Harris
K
K
Jubin
N J
NJ
Bainbridge
N R
NR
Jordan
D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D002478:Cells, Cultured; D005347:Fibroblasts / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053556:Keratin-1 / Q000378:metabolism; D053555:Keratin-5 / Q000378:metabolism; D015603:Keratinocytes / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000166:cytology / Q000293:injuries*; D014945:Wound Healing / Q000502:physiology*
D053556:Keratin-1; D053555:Keratin-5