Acidic pH-activated Cl− Current and Intracellular Ca2＋ Response in Human Keratinocytes

• 영문명: Acidic pH-activated Cl⁻ Current and Intracellular Ca^2＋ Response in Human Keratinocytes
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Su Jung Park Won Woo Choi Oh Sang Kwon Jin Ho Chung Hee Chul Eun Yung E Earm Sung Joon Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제12권 제4호, 177~184쪽, 전체 8쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2008.01.01

영문 초록

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 1ՌM). I_Cl,pH became more sensitive to pH_e by raising temperature from 24^oC to 37^oC. 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＋] (⁘[Ca^2＋]_acid) of HaCaT cells. The ⁘[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 ⁘[Ca^2＋]_acid. In summary, we found I_Cl,pH and ⁘[Ca^2＋]_acid in human keratinocytes, and these ionic signals might have implication in pathophysiological responses and differentiation of epidermal keratinocytes.

키워드

Keratinocyte Extracellular pH Anion channel Intracellular calcium pH-activated Cl- current