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• Novel potential role of neuropeptides in the pathogenesis of psoriasis and as new therapeutic targets

α-Melanozyten-stimulierendes Hormon (α-MSH) ist ein Tridekapeptid, das in der Haut selbst aus dem Prakursor Proopiomelanokortin gebildet wird. Es vermittelt Ultraviolett-Licht-vermittelte Pigmentierung nach Binding an Melanokortin-1-Rezeptoren (MC-1R), die u. a. auf der Oberflache von epidermalen Melanozyten exprimiert sind. Die pigmentinduzierende und zytoprotektive Wirkung von α-MSH bildet das Rationale fur den ersten klinischen Einsatz eines subkutan applizierbaren synthetischen und superpotenten α-MSH-Analogons, Nle4-D-Phe7-α-MSH (NDP-α-MSH), in Phase-II-Studien bei Patienten mit Photodermatosen, z. B. der erythropoietischen Protoporphyrie. Da α-MSH in einer Reihe von praklinischen Untersuchungen neben seiner melanotropen Wirkung auch vielversprechende antiinflammatorische und antifibrotische Effekte gezeigt hat, wird es von grosem Interesse sein, diese Eigenschaften anhand weiterer klinischer Pilotstudien mit NDP-α-MSH zu uberprufen. Neben synthetischen α-MSH-Analoga bieten daruber hinaus Tripeptid-Derivate wie KdPT, die nicht an MC-1R binden, aber erhaltene antiinflammatorische Eigenschaften haben, eine weitere neue therapeutische Strategie in der Dermatologie.

Background: Effective and safe products are needed for long-term management of scalp psoriasis. This study investigated the long-term safety and efficacy of a two-compound formulation (calcipotriol 50 µg/g plus betamethasone dipropionate 0.5 mg/g) for scalp psoriasis. Methods: In this 52-week, international, double-blind study, 869 patients with moderate-to-severe scalp psoriasis were randomized to either a two-compound scalp formulation (n = 429) or calcipotriol (n = 440). Results: Adverse drug reactions were less frequent in the two-compound group compared with the calcipotriol group (17.2 vs. 29.5%; p < 0.001). Incidences of adverse events possibly associated with long-term corticosteroid use were low in both the two-compound (2.6%) and the calcipotriol (3.0%) groups. Disease was satisfactorily controlled in 92.3% of visits in the two-compound group versus 80.0% in the calcipotriol group (p < 0.001). Conclusion: The two-compound scalp formulation demonstrated a high level of safety and efficacy in long-term management of scalp psoriasis.

Zusammenfassung: Im vergangenen Jahrzehnt gab es erhebliche Fortschritte im Verstandnis fur die Pathomechanismen immunvermittelter Erkrankungen, die zu signifikanten Weiterentwicklungen von immuntherapeutischen Strategien gefuhrt haben. In Folge dessen ist die Anzahl spezifischer sowie unspezifischer immunmodulierender zur Therapie von Hauterkrankungen erheblich erweitert worden. Von den unspezifischen Immunmodulatoren zeigen Mycophenolatmofetil und Leflunomid viel versprechende Wirkungen bei einer Reihe autoimmun und entzundlich bedingter Hauterkrankungen. Beide Substanzen hemmen ein Schlusselenzym der Nukleotid-Biosynthese, ein Schritt, der entscheidend fur die Produktion zytotoxischer T-Zellen und die Antikorperbildung ist. Beide Substanzen haben keinen direkten Einfluss auf die DNS, wodurch moglicherweise ihr gunstiges Nebenwirkungsprofil erklart werden kann. Summary: In the past decade, there has been enormous progress in the understanding of the pathomechanisms of immune-mediated diseases, which has led to major advances in immunotherapeutic strategies. As a consequence, the armamentarjum of specific and nonspeciflc immune-modulating and immunosuppressive drugs for the treatment of skin diseases has been widely extended. Among the nonspeciflc immunomodulators, mycophenolate mofetil and leflunomide show promising effects in a variety of autoimmune and inflammatory skin disorders. Both compounds inhibit a key enzyme in nucleotide biosynthesis, a step that is pivotal for the production of cytotoxic T cells and antibody formation. They do not act in the nucleus, wbich may explaln their advantageous side-effect profile.

Verschiedene therapeutischen Optionen in der Behandlung der Melanome, T-Zell-Lymphome, B-Zell-Lymphome, Spinaliome, Basalzellkarzinome und Merkel-Zell-Karzinome beinhalten Zytokine. Zytokintherapien umfassen die Zytokinsubstitution, Zytokininduktion, Zytokintransfektion und therapeutische Zytokinkonstrukte. In der adjuvanten Behandlung des Melanoms etabliert sich zunehmend der Einsatz von IFN-α. Auswertungen randomisierter adjuvanter Studienprotokolle sprechen fur eine statistisch signifikante Verlangerung des rezidivfreien Intervalls. IL-2 hat einen Stellenwert in der Therapie fortgeschrittener Stadien des Melanoms wie auch im Rahmen von Vakzinierungen. Weitere mogliche therapeutische Immunmodulatoren, die experimentell und in Pilotstudien uberpruft werden, sind IL-4, IL-7 und GM-CSF. Eine vielversprechende Behandlungsmoglichkeit beruht auf dem Einsatz von IL-12. In der Behandlung der kutanen T-Zell-Lymphome konnte durch eine Phase III-Studie die kombinierte PUVA-IFN-α Behandlung als ein Standard in den Stadien IA-IIB etabliert werden. In-vitro-Daten erharten zunehmend die (patho)physiologische Bedeutung des IL-12, so dass die Substitutionstherapie bereits in Phase I-Studien untersucht wurde. Weitere therapeutische Ansatze sind neben IL-2 und IFN-γ das fusionierte Zytokin-Toxin-Molekule DAB389IL-2. Beim B-Zell-Lymphom werden Antikorper-IL-2-Fusionsproteine untersucht. Fur Spinaliome und Basalzellkarzinome, speziell bei inoperablem Status, ist die lokale IFN-α-Therapie eine mogliche Option. Und auch beim Merkel-Zell-Karzinom kann bei Rezidiv oder Progress der Einsatz von IFN-α oder aber auch TNF-α erwogen werden. Die Domane der Zytokintherapien in der dermatologischen Onkologie ist nach aktuellem Stand dem Melanom und dem T-Zell-Lymphom vorbehalten und findet da zumeist in multimodalen Ansatzen ihre Anwendung.

The human growth hormone/human chorionic somatomammotropin (hGH/hCS) gene cluster contains five genes: hGH-N, hGH-V, hCS-A, hCS-B, and hCS-L. In this study, the nature of splicing products of their primary transcripts (except hCS-L) was analyzed by nuclease mapping as well as by reverse transcription-polymerase chain reaction (RT-PCR) experiments. All the previously described hGH-N mRNAs encoding the normal 22-K growth hormone, the 20-K variant as well as a transcript lacking the third exon were found in pituitary tissue and in transiently transfected human 293-S cells. In addition, splicing products lacking either exons 3 and 4 or exons 2, 3 and 4 were found in both tissues. In accordance to previously reported data,the hGH-V, the hCS-A and the hCS-B genes which are expressed in placental tissue give rise to the 22-K mRNA but not to 20-K mRNA. Furthermore, no hCS mRNA arising from skipping of exon 3 was present, whereas mRNAs arising from ligation of exon 2 to exon 5 and of exon 1 to exon 5 were clearly detectable. The various hGH cDNAs were expressed in vivo and screened for lactogenic activity. Only the 22-K and the 20-K variant were active in this assay. All of the hGH-N-derived differentially processed RNAs were found in cell lines of lymphoid (Hut-78) and of myelomonocytic type (U937), which had been recently described to secrete growth hormone. Interestingly, RT-PCR analysis allowed the determination of hGH-N transcripts in dermal fibroblasts. This finding underlines the importance of growth hormone in influencing immune system development and further suggests possible autocrine/paracrine regulatory loops in skin tissue.

The study objectives were to investigate serum levels of interleukin-6 and C-reactive protein (CRP) after liver transplantation to correlated measurements with various clinical parameters. Twenty-three patients were studied after orthotopic liver transplantation. Serum IL-6 activity was evaluated by testing its capacity to induce proliferation of the IL-6-dependent hybridoma cell line B9. CRP was assessed by a nephelometric method. Only two of seven patients with acute cellular rejection developed an increase of serum IL-6 and CRP. In contrast to this rejection group, elevated IL-6 levels were observed in 7/9 patients with bacterial infections. Peak values for IL-6 were observed one day and for CRP two days after clinical diagnosis of infection. CMV disease was also associated with markedly increased IL-6 and CRP levels in 5/7 patients. Surprisingly, levels in this condition were approximately in the same range as in bacterial infection. IL-6 and CRP serum levels seen in bacterial infection and CMV disease were significantly higher than those in rejection (P less than 0.001). Serum IL-6 activity was neutralized by an antiserum directed against recombinant human IL-6. Preferential elevations of IL-6 and CRP represent one feature of bacterial and viral infections. Elevation of TNF during rejection as described earlier is only rarely accompanied by increased serum IL-6 levels.

The utility of high-performance liquid chromatography (HPLC) in the purification of Interleukin 1 (IL 1, lymphocyte-activating factor) has been investigated Human IL 1-containing supernatants were concentrated by lyophilization and desalted using Bio-Gel P-6 DG desalting gel. Subsequently, the sample containing IL 1 activity was subjected to HPLC with a novel HPHT hydroxylapatite column. Using a sodium phosphate gradient, IL 1 was eluted as a single peak of activity separated from the major protein contaminant, yielding 90% recovery and a specific activity of 6.3 X 10(4) U/mg. Pooled fractions from Bio-Gel HPHT were concentrated and subjected either to Bio-Sil IEX 540 DEAE anion-exchange or Bio-Sil TSK 125 size exclusion chromatography. From DEAE the IL 1 activity was eluted before a linear sodium chloride gradient was started, whereas the protein contaminant was eluted at 110 mM NaCl. When TSK was used IL 1 activity was eluted within a molecular weight range of 20,000-10,000. Fractions from the DEAE or TSK columns that were positive for IL 1 activity did not contain detectable protein, suggesting a good resolution. Furthermore, the recovery from DEAE was 26% whereas TSK 125 yielded 119% of the original activity. The specific activities were 6 X 10(7) and 2.5 X 10(8) U/mg, respectively. Thus, this method provides a rapid and reproducible procedure for the purification if IL 1 for further biological characterization.

Within the last decade it has been found that the keratinocyte is not only a mechanical barrier to the outside but is also a fully immunocompetent cell that can release immunomodulating cytokines such as interleukin (IL) 1, IL 3, IL 6 and colony-stimulating factors (CSF). The constitutive production of these mediators by keratinocytes both in vivo and in vitro is very low; however, it can be dramatically enhanced by various stimuli such as tumour promotors or endotoxin. In addition, UV light is one of the most potent inducers of cytokine release. Accordingly, UV exposure results in increased production of IL 1, IL 3, IL 6, tumour necrosis factor and granulocyte/macrophage-CSF by epidermal cells. The secretion of these cytokines causes local immunologic and inflammatory reactions following UV irradiation. These factors, however, may also enter the circulation and thus may be responsible for systemic effects. In addition, UV light causes keratinocytes to release immunosuppressive factors which block contact hypersensitivity reaction and IL 1 activity. The production of such immunoinhibitors may play an essential pathogenic role during systemic UV-induced immunosuppression. This review will focus on the biological effects of epidermal-cell-derived cytokines, whose release is induced by UV light, and their role in immunologic and inflammatory reactions following UV exposure will be discussed.

High-performance liquid chromatography (HPLC) is useful for the purification and separation of immunoregulatory cytokines, such as macrophage-derived interleukin 1 (IL 1). In addition to macrophages, epidermal cells also release a mediator, epidermal cell (EC) derived thymocyte-activating factor (ETAF), whcih cannot be separated from IL 1. Moreover, it has been shown recently that EC produce a distinct interleukin 3-like mast cell-activating factor (EC IL 3). This study was performed to investigate whether HPLC may be useful for the separation of EC-derived cytokines, such as ETAF and EC IL 3. For factor production, a murine EC line (Pam 212) was used. ETAF activity was measured using the thymocyte costimulator assay. EC IL 3 was was determined by induction of the proliferative activity of an IL 3-dependent cell line (32 DCL). Using a TSK 125 size-exclusion column and phosphate-buffered saline (pH 7.2) as the mobile phase, ETAF was eluted with an apparent molecular weight of 17 kD, and EC IL 3 with a molecular weight of 28 kD. When EC supernatants were chromatofocused on a Mono P column, ETAF activity was eluted with apparent p I values of 6.8, 6.2 and 5.3, and ECL IL 3 activity with p I 7.8, 7.4 and 7.1. When reversed-phase HPLC (RP-HPLC) (equilibration with water and a 0–100% concave acetonitrile gradient) was applied ETAF exhibited four distinct peaks, whereas EC IL 3 was eluted as one major peak between 70 and 80% acetonitrile. Separation on a Bio-Gel HPHT column with a sodium phosphate gradient was not satisfactory, but the recovery was high. It is concluded that chromatofocusing on Mono P and RP-HPLC are suitable methods for the separation of cytokines, such as ETAF and EC IL 3, both of which are produced by EC.

In a pilot study, serum ferritin levels of patients with malignant melanoma were found to be increased in stage III of the disease. Therefore, serial determinations were carried out up to 24 months in patients at various stages of the disease undergoing either chemo- or immunotherapy. Serum ferritin was determined by a two-site IRMA technique. Serum samples of 91 patients in different clinical stages of histologically verified malignant melanoma were included in these investigations. 80 healthy individuals were also investigated to determine normal ranges of serum ferritin. In stage III serum ferritin levels were significantly elevated (p less than 0,0005), whereas in stages I and II the values were within the normal range. Repeated serum ferritin levels of 10 patients in stage I and 13 patients in stages II and III without evidence of tumor progression were within the normal range. In 9 patients in stage III the increases in serum ferritin concentration correlated with the degree of dissemination of metastasis. Because of the occurrence of increased ferritin levels only in melanoma patients with progressive metastatic disease, the measurement of serum ferritin might have limited utility in clinical evaluation of melanoma patients as well as in the prediction of recurrence and in monitoring response to therapy.