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Updated: Jun 18, 2026

Generation and Culturing of Primary Human Keratinocytes from Adult Skin
Published on: December 22, 2017
Acidic pH-activated Cl Current and Intracellular Ca Response in Human Keratinocytes
Su Jung Park1, Won Woo Choi, Oh Sang Kwon
1Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Korea.
Abstract:
The layers of keratinocytes form an acid mantle on the surface of the skin. Herein, we investigated the effects of acidic pH on the membrane current and [Ca(2+)](c) of human primary keratinocytes from foreskins and human keratinocyte cell line (HaCaT). Acidic extracellular pH (pH(e)= 5.5) activated outwardly rectifying Cl(-) current (I(Cl,pH)) with slow kinetics of voltage-dependent activation. I(Cl,pH) was potently inhibited by an anion channel blocker 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS, 73.5% inhibition at 1 microM). I(Cl,pH) became more sensitive to pH(e) by raising temperature from 24 to 37. HaCaT cells also expressed Ca(2+)-activated Cl(-) current (I(Cl,Ca)), and the amplitude of I(Cl,Ca) was increased by relatively weak acidic pH(e) (7.0 and 6.8). Interestingly, the acidic pH(e) (5.0) also induced a sharp increase in the intracellular [Ca(2+)] (Delta[Ca(2+)](acid)) of HaCaT cells. The Delta[Ca(2+)](acid) was independent of extracellular Ca(2+), and was abolished by the pretreatment with PLC inhibitor, U73122. In primary human keratinocytes, 5 out of 28 tested cells showed Delta[Ca(2+)](acid). In summary, we found I(Cl,pH) and Delta[Ca(2+)](acid) in human keratinocytes, and these ionic signals might have implication in pathophysiological responses and differentiation of epidermal keratinocytes.
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