In addition to their antibiotic effects, tetracyclines have anti-inflammatory action that is often beneficial in the control of inflammatory skin disorders. In this study, we examined the effects of tetracycline (TET) and two of its derivatives, doxycycline (DOX) and minocycline (MIN), on the production of interleukin-8 (IL-8) elicited by the activation of protease-activated receptor 2 (PAR2) in normal human epidermal keratinocytes (NHEK). In NHEK, the production of IL-8 stimulated by an agonist peptide of PAR2, SLIGKIV-NH 2 , at 100 M was significantly reduced by TET, DOX, or MIN at 5 and 10 M, concentrations that are noncytotoxic. The tumor necrosis factor alpha (TNF-␣)-induced production of IL-8 was synergistically augmented by SLIGKIV-NH 2 , and that synergistic increase in the production of IL-8 was suppressed by 100 nM PAR2-specific small interfering RNA. It was also suppressed by TET, DOX, or MIN but not by the 14-membered-ring macrolide antibiotics erythromycin, roxithromycin, and clarithromycin, which also have anti-inflammatory activities, at 10 M. These results suggest that tetracyclines attenuate the PAR2-IL-8 axis in keratinocytes and thereby effectively modulate proinflammatory responses in the skin.

Protease-activated receptor 2 (PAR2) is a G protein-coupled receptor which mediates a variety of functions in the skin including cutaneous inflammation. SLIGKV-NH(2) , an agonist peptide for PAR2, enhanced the interleukin (IL)-17-induced production of two CXC chemokines, CXCL1 (GRO-α) and CXCL8 (IL-8), in normal human epidermal keratinocytes (NHEK) in a concentration-dependent manner. The enhanced production of those chemokines was suppressed by a PAR2-specific siRNA. The SLIGKV-NH(2) -induced production of both CXCL1 and CXCL8 was markedly reduced by cyclosporine A. The enhanced production of CXCL1 was suppressed by 1α, 24R-dihydroxyvitamin D(3) , an active form of vitamin D(3) , and weakly by glucocorticoids, dexamethasone and clobetasol propionate, whereas production of CXCL8 was not altered by any of those receptor agonists. In psoriatic skin, the thickened upper spinous layer of the epidermis was positive for PAR2 protein and the expression of the IL17A mRNA was increased. These results suggest that the IL-17-induced pro-inflammatory reaction is enhanced by the activation of PAR2 in keratinocytes, and that the effect of PAR2 is differentially modulated by cyclosporine A, the active form of vitamin D(3) and glucocorticoids.

The production of interleukin-8 induced by the activation of protease-activated receptor 2 and its synergism with interleukin-1␤ were modulated by 14-membered-ring macrolides, namely, roxithromycin, erythromycin, and clarithromycin, in cultured normal human epidermal keratinocytes. Those macrolides may attenuate the protease-activated receptor 2-interleukin-8 axis and thereby modulate proinflammatory responses in the skin.

A novel point mutation of keratin 17 (KRT17) in a Japanese family with pachyonychia congenita type 2: an RNA-based genetic analysis using a single hair bulb

Solid substrate room-temperature phosphorimetry (SS-RTP) is widely known as a sensitive and simple analytical technique for determination of trace amounts of organic compounds. Among the utilizable substrate materials, filter paper is the most commonly used. Filter paper does, however, have some drawbacks; e.g., it has considerable background emissions, the removal of which requires labor-intensive treatment, and continuous dry gas flow through the sample compartment of the spectrophotometer is necessary during measurement of RTP emissions because moisture and oxygen can quench emissions of the analytes. To overcome these drawbacks, we have investigated and report herein on a new solid substrate prepared from poly(vinyl alcohol) (PVA).1) The best feature of this substrate is that it does not require any dry gas flush of the sample compartment during RTP measurement because the RTP intensity is very stable, even with atmospheric exposure. Furthermore, PVA has negligibly weak background emissions.2)The presence and/or amount of ofloxacin (OFLX), a new synthetic quinolone antibiotic with a broad spectrum of activity against gram-positive and gram-negative bacteria, is detected primarily by methods of fluorimetry and spectrophotometry, which are easily carried out. [3][4][5][6][7] Up to now, the most common technique for the determination of OFLX in pharmaceutical tablet has been based on HPLC with fluorescence or UV detection. [8][9][10] However, these methods need comparatively large amounts of sample solution. In order to develop a micro and trace analysis of OFLX by an easy method, we applied the PVA-substrate RTP to the analysis of OFLX. ExperimentalMaterials and Reagents PVA, degree of polymerization 2000 and degree of hydrolysis 78-82 mol% (Kanto Chemical); OFLX (Sigma); sodium hydroxide, extra-pure grade (Kanto Chemical); thallium(I) nitrate, extrapure grade (Kanto Chemical); and potassium iodide, extra-pure grade (Kanto Chemical), were used as purchased without further purification. Purified distilled water (Milli-Q, Millipore) was used as the solvent.Solutions The solutions for the RTP measurement were prepared as follows. Stock solutions of OFLX were prepared in water or an aqueous NaOH solution of appropriate concentration. Stock solutions of NaOH, TlNO 3 , and KI were prepared in water. Working solutions of lower concentration were obtained by an appropriate dilution of stock solution with water or the appropriate aqueous NaOH solution.For the UV photometry, a stock solution of OFLX was prepared in water, and working solutions of lower concentration were obtained by appropriate dilution of stock solution with water.For the fluorimetry, a stock solution of OFLX was prepared in a 49.55 mM phthalate buffer solution, and working solutions of lower concentration were obtained by an appropriate dilution of stock solution with the buffer solution.For analysis of the commercial tablet, solutions were prepared as follows. Five tablets were accurately weighed and powdered. An amount of powder equivalent to one ta...