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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http://dx.doi.org/10.4196/kjpp.2008.12.4.177 | DOI Listing |
Nanoscale
December 2024
Department of Chemistry, Faculty of Nano and Bio Science and Technology, Persian Gulf University, Bushehr, Iran.
Traditional Fenton-like reactions, commonly employed in chemodynamic therapy (CDT) for cancer treatment, face limitations due to the mildly acidic tumor microenvironment (TME) and scarce HO availability. Aiming to overcome these hurdles, we report herein the preparation of copper-cobalt peroxide (CCp) nanoparticles, a novel catalyst that enables a pH-activated, self-supplying HO-mediated cascade reaction. In the slightly acidic TME (pH 6.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2025
School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei 230032, Anhui, China. Electronic address:
Nanozymes have made great achievements in the research of tumor therapy. However, due to the complex tumor microenvironment, the catalytic activity and biosafety of nanozymes are limited. High catalytic efficiency is a relentless pursuit for the preparation of high-performance nanozymes.
View Article and Find Full Text PDFAnal Chem
November 2024
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Hunan University, Changsha 410082, China.
Allostery is a phenomenon where the binding of a ligand at one allosteric site influences the affinity for another ligand at an active site. Different from orthosteric regulation, it allows for more precise control of biomolecular activity and enhances the stability of the molecules. Inspired by allosteric regulation of natural molecules, we present a Y-shaped allosteric DNA nanodevice, termed YssAP, that was pH-responsive and functionalized with the AS1411 aptamer for accurate fluorescence imaging of human apurinic/apyrimidinic endonuclease (APE1) activity in tumor cells.
View Article and Find Full Text PDFChem Sci
September 2024
State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology Beijing 100029 China
Visualization of drug release is crucial for improving therapeutic efficacy and preventing inappropriate medication dosing, yet, challenging. Herein, we report a pH-activated chemo-immunotherapy nanoplatform with visualization of drug release by ratiometric F magnetic resonance imaging (F MRI). This nanoplatform consists of ultra-small histamine-modified perfluoro-15-crown-5-ether (PFCE) nanodroplets loaded with doxorubicin (Dox), which are packaged in trifluoromethyl-containing metal-organic assemblies coordination-driven self-assembly.
View Article and Find Full Text PDFChemistry
September 2024
Department of Chemistry, Organic Chemistry Section, Jadavpur University, 700032, Kolkata, India.
We have synthesized an acidic pH-activatable dual targeting ratiometric fluorescent probe-peptide conjugate using the SPPS protocol on Rink amide AM resin. Living carcinoma cell specific active targeting, successive cell penetration, and selective staining of lysosomes are accomplished. Real-time monitoring of lysosomes, 3D, and multicolor cancer cell imaging are also attained.
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