Inflammation In Human Skin Research Articles

Effects of local treatment with salmeterol and terbutaline on anti-IgE-induced wheal, flare, and late induration in human skin

The capacity of terbutaline and the long-acting beta 2-agonist salmeterol to suppress wheal-and-flare reactions (WFRs) to intradermal antihuman IgE and to histamine was evaluated in 36 healthy volunteers. We also examined effects of the two drugs on the subsequent late cutaneous reaction (LCR) to anti-IgE. Salmeterol (10(-10)-10(-6) M) and terbutaline (10(-10)-10(-5) M), injected intradermally 2 or 15 min before anti-IgE challenge, produced a dose-dependent inhibition of the WFRs to anti-IgE (titer 1 : 10000) with a maximal effect of approximately 60% (wheal) and approximately 75% (flare) by both drugs. On a molar basis, salmeterol was approximately 10-100 times more potent than terbutaline in inhibiting the WFRs. Moreover, the wheal response to histamine (4 nmol) was antagonized by approximately 40% after pretreatment with either salmeterol (10(-5) M) or terbutaline (10(-4) M). We found that both salmeterol and terbutaline exhibited anti-WFR activity for up to 24 h, salmeterol being significantly more potent in this regard. When selecting a 15-min pretreatment interval with equieffective anti-WFR doses from the first dose-response experiments (i.e., a salmeterol: terbutaline ratio of 1 : 10), the WFRs to high-dose anti-IgE (titer 1 : 100) were inhibited by terbutaline (10(-5) M) by 25-30%, but not by salmeterol (10(-6)). On the other hand, salmeterol attenuated (by up to approximately 35%) the subsequent LCR more effectively than terbutaline. As compared to the pretreatment procedure, infiltration of the drugs (single doses) into the wheals 30 min after challenge with anti-IgE (titer 1 : 100) proved to be less effective on the development of LCRs. Taken together, salmeterol was found to express higher potency and have longer duration of action than terbutaline in inhibition of IgE-mediated inflammation in human skin.

Immunohistochemical localization of interleukin-6-like immunoreactivity to peripheral nerve-like structures in normal and inflamed human skin

Immunohistochemical localization of interleukin-6-like immunoreactivity to peripheral nerve-like structures in normal and inflamed human skin

Immunohistochemical localization of interleukin-6-like immunoreactivity to peripheral nerve-like structures in normal and inflamed human skin

Immunohistochemical localization of interleukin-6-like immunoreactivity to peripheral nerve-like structures in normal and inflamed human skin

Absence of MHC class II antigen on mast cells at sites of inflammation in human skin.

Since the presence of major histocompatibility complex (MHC) antigens has recently been reported on murine and human mast cells under various conditions, we have investigated their expression on mast cells in different types of cutaneous inflammation. Cryostat sections from lesional biopsies of patients with psoriasis, atopic eczema, chronic urticaria, lichen planus, bullous pemphigoid and urticaria pigmentosa were immunohistochemically stained with monoclonal antibodies against MHC class I and class II antigens using a double staining APAAP/toluidine blue methodology. While strongly positive staining with the antibody directed against MHC class I antigens was found on nearly all mast cells in normal skin and in inflammatory dermatoses, reactivity for HLA-DR and HLA-DQ antigens on mast cells could not be detected, except for less than 2% of cells with doubtful staining. Human mast cells therefore probably play no significant rôle as antigen-presenting cells in the conditions studied.

Immunohistochemical localization of interleukin-6-like immunoreactivity to peripheral nerve-like structures in normal and inflamed human skin.

Interleukin-6-like (IL-6-like) immunoreactivity was sought in inflamed and normal human skin using the same immunohistochemical technique as for detection of neuropeptides. Such immunoreactivity was found in dermal and in a few intraepidermal nerve-like fibres in biopsy specimens from inflamed skin from patients with positive epicutaneous patchtest reactions to nickel sulphate, and in skin specimens from patients with atopic dermatitis and prurigo nodularis. However, IL-6-like immunoreactivity was also found in nerve-like fibres in specimens from nonlesional skin. In skin from patients with positive epicutaneous patch-test reactions there was a statistically significantly (P<0.01) higher number of IL-6-positive nerve fibres in the epidermis than in normal skin, in contrast to the papillary dermis, in which no difference was found. Moreover, there were clusters of nerve-like fibres with IL-6-like immunoreactivity in the dermis of prurigo nodularis lesions. In these nerve-like fibres, the colocalization of the immunoreactivities for IL-6 and calcitonin gene-related peptide was indicated. Localization of immunoreactivity to nerve-like structures surrounding the eccrine sweat glands indicates that IL-6 is present in autonomic as well as in sensory nerve fibres.

A Single Parameter, Oxygenated Hemoglobin, Can Be Used to Quantify Experimental Irritant-Induced Inflammation

To quantify the dose-response relation of irritant-induced erythema, we examined inflammation in human skin after application of an irritant, using perpendicular polarized photography and diffuse reflectance spectroscopy as compared to clinical visual scoring. The ventral forearms of 11 healthy subjects were patch-tested for 24 h under occlusion in finn chambers with five concentrations of the irritant sodium lauryl sulfate. The tested sites and three control sites were evaluated clinically for erythema at 24, 48, and 72 h after occlusion, photographed using standard and perpendicular polarized photography, and measured by diffuse reflectance spectroscopy. All photographs were evaluated for erythema by three investigators. Diffuse reflectance spectra were analyzed, and changes in apparent oxyhemoglobin and deoxyhemoglobin concentrations were estimated. Clinical and photographic assessments of erythema yielded similar linear dose-response relations. A linear dose-response relation, with no minimum threshold, also was obtained for changes in the apparent oxyhemoglobin concentration with increasing irritant dose, whereas the apparent deoxyhemoglobin concentrations were unchanged with increasing dose. These results show that diffuse reflectance spectroscopy permits the characterization of irritant-induced inflammation in terms of a single parameter, the apparent concentration of oxyhemoglobin, and that irritant-induced inflammation primarily involves the capillaries and the superficial arterial plexus.

Differential expression of heat shock protein 70 (HSP70) and heat shock cognate protein 70 (HSC70) in human epidermis.

Autoimmunity and microbial agents have been suggested as playing a pathogenetic role in psoriasis. Since immune responses to microbial infections are often directed towards heat shock proteins (HSP), we investigated the expression of three HSP families in normal and inflamed human skin. Specimens from ten patients with psoriasis and three patients with positive patch tests for nickel and from five healthy volunteers were analysed by means of immunohistochemistry. The patterns observed were qualitatively similar in these conditions showing only minor quantitative differences. Psoriatic epidermis exhibited the highest level of expression. HSP27, HSP70 and heat shock cognate protein 70 (HSC70) were readily detectable. HSP27 was homogeneously distributed throughout the epidermis, whereas HSP70 was restricted to the basal layer and HSC70 primarily to the suprabasal layers. Other HSPs were detected to a lesser degree and showed a more irregular pattern. Thus, the qualitative expression pattern of HSPs seems to be constant between different skin conditions, but the expression of constitutive and inducible HSP70 depends on the differentiation state of keratinocytes.

Platelet activating factor (PAF) and lyso-PAF in inflamed human skin

The extent of PAF synthesis and its role in inflammatory skin disorders are not known. Skin exudates were collected from suction blisters or bbrasions on healthy and inflamed human skin and analysed by gc-ms. The mean PAF andlyso-PAF values for skin of healthy subjects were 1.86±0.92 (n=7) and 160±21 (n=8) nM, respectively, in suction blister exudates, and 0.38±0.08 (n=14) and 11.0±1.9 (n=13) pmol/abrasion, respectively. PAF levels were not altered in psoriasis, nickel contact dermatitis, delayed pressure urticaria, mastocytosis or immediate and late phase reactions to antigen. Significantly, lesslyso-PAF was found in uninvolved skin of psoriasis. Increasedlyso-PAF was found in nickel contact dermatitis compared with untreated skin of the same subjects or skin or normal healthy volunteers. We conclude that, if PAF is a significant mediator of inflammation in human skin, it may remain associated with the synthesising cell or act in its immediate proximity.

Different patterns of hyperalgesia induced by experimental inflammation in human skin.

Different types of hyperalgesia were studied after experimental induction of inflammation in small skin areas of healthy volunteers either by topical application of capsaicin solution (1% in 70% ethanol) or by briefly freezing a skin area of similar size to -28 degrees C. Sensory tests were performed 30 min after capsaicin application and 22 h after freeze lesions. Heat pain thresholds were lowered after both treatments, probably due to nociceptor sensitization. Hyperalgesia to four types of mechanical stimulation was studied. (i) Hyperalgesia to punctate stimuli was encountered at the skin site directly affected by the noxious chemical or freeze stimulus (1 degree zone) and in the surrounding skin (2 degrees zone) in both models though the area of 2 degrees hyperalgesia to punctate stimuli after freezing was smaller than after capsaicin. (ii) Hyperalgesia to gently brushing the skin was prominent after capsaicin in 1 degree and 2 degrees zone, but almost absent after freezing. It was concluded that both hyperalgesia to punctate stimuli and brush-evoked pain are due to central nervous plasticity changes rather than nociceptor sensitization. As revealed by differential nerve blocks, brush-evoked pain is mediated by low threshold mechanosensitive A beta-fibres, whilst hyperalgesia to punctate stimuli can be elicited when only C-fibres conduct. In contrast to hyperalgesia to punctate stimuli it requires continuous background discharges in nociceptor units. (iii) Pressure hyperalgesia to tonic stimulation with a blunt probe was encountered in the 1 degree zone of both types of inflammation and is probably due to recruitment of sensitized nociceptor units. (iv) Impact hyperalgesia was studied by shooting small bullets against the skin at predetermined velocities. It was found in the 1 degree zone after freezing and absent in the capsaicin model. Differential nerve blocks revealed that it is probably mediated by sensitized C-fibres. In conclusion, different types of inflammatory changes may result in characteristic different patterns of hyperalgesia.

Localization of annexins in normal and diseased human skin

Annexins (AX) or lipocortins are a family of calcium and phospholipid binding proteins that have been implicated to play a role in the regulation of inflammation and cellular differentiation. To investigate a potential role of AX in skin disorders we studied the distribution of six different AX in normal human skin (NHS) and several inflammatory and hyperproliferative skin diseases. A distinct staining pattern could only be shown for AX-1 and AX-2. In NHS AX-1-antibody (Ab) displayed a very strong reactivity with eccrine sweat ducts. In the diseases investigated we found a highly increased expression of AX-1 in keratinocytes (KCs) in the vincinity of inflammatory processes such as psoriasis. Furthermore, the AX-1 expression was increased in differentiated squamous cell carcinoma (SCC) whereas undifferentiated SCC and basal cell carcinoma were negative. AX-3, -4, -5, and -6 showed no distinctive expression pattern. Our data demonstrate an abnormal distribution of AX-1 in association with proliferating KCs under inflammatory and neoplastic conditions. Its pattern of reactivity shows similarities to the known distribution of the EGF-receptor kinase, which has been demonstrated to phosphorylate AX-1 with high activity in various cellular systems. These results support the concept that the appearance of AX-1 is linked to a certain level of KC differentiation.

Differential time courses of hyperalgesia and inflammation in human skin after ultraviolet irradiation

Differential time courses of hyperalgesia and inflammation in human skin after ultraviolet irradiation

Skin-infiltrating lymphocytes in normal and disordered skin: activation signals and functional roles in psoriasis and mycosis fungoides-type cutaneous T cell lymphoma.

T lymphocytes recruited into the skin can experience several different outcomes. On the one hand, they may be recruited by adhesion molecules and chemoattractants to enter the perivascular space, but never undergo activation. Other T cells undergo activation and further differentiation under the influence of the cutaneous milieu. These activated lymphocytes then coordinate specific and non-specific immune responses characteristic of inflamed tissue. We have explored two models for studying the activation and function of skin infiltrating T lymphocytes (SIL's). In the first model, we have identified a family of Langerhans cell-related professional dendritic antigen presenting cells that exist in the epidermis and dermis of normal skin, atopic skin, and mycosis fungoides skin. These have APC abilities to activate freshly recruited resting blood T cells that are distinct from another family of macrophage-related cells abnormally present in sunburned or psoriatic skin. In the second model, we examined the function of cells that have already been recruited into the skin of patients with psoriasis and mycosis fungoides. Lesional psoriasis and mycosis fungoides T cells exhibited a variety of T cell receptor gene rearrangements, conclusively demonstrating that heterogeneous populations of T lymphocytes exist in inflamed human skin. From psoriasis, clones were identified that were particularly effective at inducing normal keratinocytes to assume "psoriatic" phenotypic features and functions. Thus, lesional psoriatic SIL's could induce HLA-DR, ICAM, and CDw60 on normal keratinocytes. In addition, psoriatic SIL's induced increased keratinocyte proliferation and cytokine profile changes characteristic of psoriatic epidermis.(ABSTRACT TRUNCATED AT 250 WORDS)

Glycolytic activity in intense light exposed rat retinas: Winkler, B.S. and Organisciak, D.T. Eye Research Institute, Oakland University, Rochester, MI. and Department of Biochemistry, Wright State University, Dayton, OH

Long wave ultraviolet radiation (UVA) has been shown to play an important role in the overall response of skin to solar radiation, including sunburn, tanning, premature aging, and non-melanoma skin cancer. UVA induction of inflammation in human skin is thought to be mediated by membrane lipid derived products. In order to investigate the mechanism of this response we examined the effect of UVA on phospho-lipid metabolism of human epidermal keratinocytes in culture. Keratinocytes were grown in serum free low calcium medium. The cells were prelabeled with [3H] arachidonic acid or [3H] choline and irradiated with UVA (Honle 2002-Hg vapor lamp). Identification and quantitation of specific membrane phospholipid-derived components was achieved using high-performance liquid chromatography, paper chromatography, and radioimmunoassay. UVA resulted in a linear dose dependent release of [3H] arachidonic acid into medium between 1 and 20 joule/cm2. This response was inhibited in an oxygen-reduced environment. The radiolabel released was predominately free arachidonate and cyclooxygenase metabolites. Cyclooxygenase metabolites prostaglandin E2 and prostacyclin derivative, 6- keto-prostaglandin F12, were stimulated following UVA irradiation, but the lipoxygenase metabolite, leukotriene B4 was not detected. Maximal release was measured immediately after irradiation and changed little over 24 h post-irradiation. UVA stimulated an increase of [3H] choline metabolites glycerophosphoryicholine and phosphorylcholine in media extracts suggesting UVA activation of phospholipase C and phospholipase A2 or diacylglyceride lipase.

Interleukin 1 receptor antagonist in human epidermis and cultured keratinocytes

Interleukin 1 (IL-1), present in high amounts in normal human skin without any sign of inflammation, suggests a complex mechanism by which its bioactivity is regulated. The specific receptor antagonist of IL-1 (IL-1ra) was analyzed in human skin, sweat and cultured keratinocytes. Extracts of both skin and cultured keratinocytes blocked the binding of [ 125I]IL-1 to its receptor whereas sweat did not. The inhibitory activity was cell-associated, was not secreted by cultured keratinocytes, and IL-1ra mRNA was identified in these cells. There was an inverse relationship between the level of IL-1ra and that of IL-1α and β since extracts of differentiating keratinocytes (DK) and higher IL-1ra levels and expressed more mRNA for IL-1ra than non-differentiated keratinocytes (NDK), whereas NDK contained 4 times more IL-1α and β proteins than DK. This association of cell differentiation with a shift in agonist/antagonist ratio might be related to important autocrine or paracrine functions of IL-1 in normal and inflamed human skin.

Calcitonin gene-related peptide, neurokinin A and substance P: Effects on Nociception and neurogenic inflammation in human skin and temporal muscle

Calcitonin gene-related peptide (CGRP) was injected alone and in combination with substance P (SP) or neurokinin A (NKA) into the forearm skin and temporal muscle of human volunteers. In the skin, 50 pmol of CGRP induced a wheal response and a delayed erythema. No pain was recorded. No interaction between CGRP and SP or NKA was observed. In the temporal muscle, 200 pmol of CGRP alone did not induce pain or tenderness but, in combination with SP or NKA, CGRP elicited a significant pain sensation. It is concluded that CGRP may be involved in neurogenic inflammation and that only SP, of the three peptides present in nociceptive C fibers, seems to be of major importance in relation to cutaneous nociception. Simultaneous neurogenic release of CGRP and other neuropeptides in skeletal muscle may induce myofascial pain.

Long-Wave Ultraviolet Light Induces Phospholipase Activation in Cultured Human Epidermal Keratinocytes

Long wave ultraviolet radiation (UVA) has been shown to play an important role in the overall response of skin to solar radiation, including sunburn, tanning, premature aging, and non-melanoma skin cancer. UVA induction of inflammation in human skin is thought to be mediated by membrane lipid derived products. In order to investigate the mechanism of this response we examined the effect of UVA on phospholipid metabolism of human epidermal keratinocytes in culture. Keratinocytes were grown in serum free low calcium medium. The cells were prelabeled with [3H] arachidonic acid or [3H] choline and irradiated with UVA (Honle 2002-Hg vapor lamp). Identification and quantitation of specific membrane phospholipid-derived components was achieved using high-performance liquid chromatography, paper chromatography, and radioimmunoassay. UVA resulted in a linear dose dependent release of [3H] arachidonic acid into medium between 1 and 20 joule/cm2. This response was inhibited in an oxygen-reduced environment. The radiolabel released was predominantly free arachidonate and cyclooxygenase metabolites. Cyclooxygenase metabolites prostaglandin E2 and prostacyclin derivative, 6-keto-prostaglandin F1a, were stimulated following UVA irradiation, but the lipoxygenase metabolite, leukotriene B was not detected. Maximal release was measured immediately after irradiation and changed little over 24 h post-irradiation. UVA stimulated an increase of [3H] choline metabolites glycerophosphorylcholine and phosphorylcholine in media extracts suggesting UVA activation of phospholipase C and phospholipase A2 or diacylglyceride lipase.

T-Cell Receptor-γ/δ Bearing Lymphocytes in Normal and Inflammatory Human Skin

Murine dendritic epidermal T cells (DETC) were recently reported to express T-cell receptor (TCR)-gamma/delta chains. In a search for the human equivalent of these cells, we tested normal and lesional skin with MoAb which react with the TCR-gamma/delta heterodimer. We performed indirect immunofluorescence (IF) on epidermal sheets, and alkaline-phosphatase-anti-alkaline-phosphatase complex (APAAP) on epidermal cell smears. Frozen skin sections from normal skin and various cutaneous lymphocyte infiltrates were also studied. A few CD3+ T lymphocytes were consistently found in normal epidermis. Most of these cells appeared to be TCR-alpha/beta +, and some CD4+ or CD8+. On epidermal sheets and cell smears, only a very small TCR-gamma/delta + cell population was visualized (less than 0.1% of the total). On normal skin sections, we observed 0 to 3 gamma/delta + cells per section. When present, they were often located in the epidermal basal layer, and were round or dendritic. Double immunolabeling revealed that gamma/delta + cells differed from CD1+ Langerhans cells, and that they had a similar phenotypic pattern as gamma/delta + peripheral lymphocytes (PBL): CD2+, CD3+, CD4-, and CD8-. Immunostaining from various inflammatory skin lesions showed that the dermal infiltrates included CD3+ T lymphocytes but virtually no gamma/delta + cells. Only a few gamma/delta + cells were found in some end-evolutive infiltrates. Taken together, these results strongly suggest that normal human epidermis occasionally harbors TCR-gamma/delta complex bearing lymphocytes, which constitute a small fraction of the CD3+ cutaneous T lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellular and Biochemical Characterization of the Anti-Inflammatory Effects of DuP 654 in the Arachidonic Acid Murine Skin Inflammation Model (Part 2 of 2)

The possible utility of DuP 654, a potent 5-lipoxygenase inhibitor, for treating human inflammatory skin disease was investigated in murine skin treated with 1.0 mg arachidonic acid (AA). When DuP 654 was applied to murine skin treated with AA, it inhibited the resulting inflammation and influx of cells. High performance liquid chromatography and radioimmunoassay analysis of lipid extracts from AA-treated ears indicated that the influx of polymorphonuclear leukocytes (PMN) was temporally preceded by an appearance of significant amounts of 5-HETE (6.7 ± 1.4 ng/ear) and Leukotriene B&lt;sub&gt;4&lt;/sub&gt; LTB4 0.92 ± 0.2 ng/ear) when compared with extracts of untreated ears (5-HETE, 02 ± 0.3 ng/ear; LTB&lt;sub&gt;4&lt;/sub&gt;, &lt; 0.1 ng/ear). The levels of the 5-lipoxygenase products were reduced by treatment with 10 µg/ear DuP 654. Lipid extracts from AA-treated ears contain chemotactic activity for human PMN and this chemotactic activity in the AA-treated ears could be reduced but not eliminated by immunosorption with anti-LTB4 antibodies coupled to protein A-agarose. The appearance of the chemotactic activity was inhibited by DuP 654. Taken together, these data suggest that DuP 654 may have utility in human inflammatory skin disease.

Cellular and Biochemical Characterization of the Anti-Inflammatory Effects of DuP 654 in the Arachidonic Acid Murine Skin Inflammation Model (Part 1 of 2)

The possible utility of DuP 654, a potent 5-lipoxygenase inhibitor, for treating human inflammatory skin disease was investigated in murine skin treated with 1.0 mg arachidonic acid (AA). When DuP 654 was applied to murine skin treated with AA, it inhibited the resulting inflammation and influx of cells. High performance liquid chromatography and radioimmunoassay analysis of lipid extracts from AA-treated ears indicated that the influx of polymorphonuclear leukocytes (PMN) was temporally preceded by an appearance of significant amounts of 5-HETE (6.7 +/- 1.4 ng/ear) and Leukotriene B4 LTB4 0.92 +/- 0.2 ng/ear) when compared with extracts of untreated ears (5-HETE, 02 +/- 0.3 ng/ear; LTB4, less than 0.1 ng/ear). The levels of the 5-lipoxygenase products were reduced by treatment with 10 micrograms/ear DUP 654. Lipid extracts from AA-treated ears contain chemotactic activity for human PMN and this chemotactic activity in the AA-treated ears could be reduced but not eliminated by immunosorption with anti-LTB4 antibodies coupled to protein A-agarose. The appearance of the chemotactic activity was inhibited by DuP 654. Taken together, these data suggest that DuP 654 may have utility in human inflammatory skin disease.

Transendothelial cell diapedesis of neutrophils in inflamed human skin

The mode of extravasation of neutrophils (PMNs) in cutaneous inflammation was studied in sequential biopsy specimens taken from human skin. Inflammatory skin reactions were produced by intracutaneous injection of endogeneous mediators of inflammation--C5ades arg, LTB4, neutrophil-activating peptide (NAP) and interleukin-1 (IL-1). Within 30 min after injection neutrophils were observed in close contact with endothelial cells of postcapillary venules and, following cytoplasmic engulfment, the cells were found to be transported transcellulary through the endothelial layer. In a total of 20 biopsy specimens taken at various times, cell migration via interendothelial gaps was absent. Instead, the transcellular pathway appeared to be the first and foremost mode of diapedesis. During this migratory process PMNs lacked signs of degranulation and numerous electron-lucent vesicles and secondary lysosomes were found. In addition, coated pits present on leukocyte as well as endothelial-cell membranes were indicative of receptor-mediated endocytotic processes.