D. Bruch-Gerharz

Nitric oxide fully protects against UVA-induced apoptosis in tight correlation with Bcl-2 up-regulation.

A variety of toxic and modulating events induced by UVA exposure are described to cause cell death via apoptosis. Recently, we found that UV irradiation of human skin leads to inducible nitric-oxide synthase (iNOS) expression in keratinocytes and endothelial cells (ECs). We have now searched for the role of iNOS expression and nitric oxide (NO) synthesis in UVA-induced apoptosis as detected by DNA-specific fluorochrome labeling and in DNA fragmentation visualized by in situ nick translation in ECs. Activation with proinflammatory cytokines 24 h before UVA exposure leading to iNOS expression and endogenous NO synthesis fully protects ECs from the onset of apoptosis. This protection was completely abolished in the presence of the iNOS inhibitorl-N 5-(1-iminoethyl)-ornithine (0.25 mm). Additionally, preincubation of cells with the NO donor (Z)-1-[N(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate at concentrations from 10 to 1000 μm as an exogenous NO-generating source before UVA irradiation led to a dose-dependent inhibition of both DNA strand breaks and apoptosis. In search of the molecular mechanism responsible for the protective effect, we find that protection from UVA-induced apoptosis is tightly correlated with NO-mediated increases in Bcl-2 expression and a concomitant inhibition of UVA-induced overexpression of Bax protein. In conclusion, we present evidence for a protective role of iNOS-derived NO in skin biology, because NO either endogenously produced or exogenously applied fully protects against UVA-induced cell damage and death. We also show that the NO-mediated expression modulation of proteins of the Bcl-2 family, an event upstream of caspase activation, appears to be the molecular mechanism underlying this protection.

Arginase 1 Overexpression in Psoriasis: Limitation of Inducible Nitric Oxide Synthase Activity as a Molecular Mechanism for Keratinocyte Hyperproliferation

Abnormal proliferation of keratinocytes in the skin appears crucial to the pathogenesis of psoriasis, but the underlying mechanisms remain unknown. Nitric oxide (NO), released from keratinocytes at high concentrations, is considered a key inhibitor of cellular proliferation and inducer of differentiation in vitro. Although high-output NO synthesis is suggested by the expression of inducible NO synthase (iNOS) mRNA and protein in psoriasis lesions, the pronounced hyperproliferation of psoriatic keratinocytes may indicate that iNOS activity is too low to effectively deliver anti-proliferative NO concentrations. Here we show that arginase 1 (ARG1), which substantially participates in the regulation of iNOS activity by competing for the common substrate L-arginine, is highly overexpressed in the hyperproliferative psoriatic epidermis and is co-expressed with iNOS. Expression of L-arginine transporter molecules is found to be normal. Treatment of primary cultured keratinocytes with Th1-cytokines, as present in a psoriatic environment, leads to de novo expression of iNOS but concomitantly a significant down-regulation of ARG1. Persistent ARG1 overexpression in psoriasis lesions, therefore, may represent a disease-associated deviation from normal expression patterns. Furthermore, the culturing of activated keratinocytes in the presence of an ARG inhibitor results in a twofold increase in nitrite accumulation providing evidence for an L-arginine substrate competition in human keratinocytes. High-output NO synthesis is indeed associated with a significant decrease in cellular proliferation as shown by down-regulation of Ki67 expression in cultured keratinocytes but also in short-term organ cultures of normal human skin. In summary, our data demonstrate for the first time a link between a human inflammatory skin disease, limited iNOS activity, and ARG1 overexpression. This link may have substantial implications for the pathophysiology of psoriasis and the development of new treatment strategies.

Nitric oxide and its implications in skin homeostasis and disease – a review

Abstract The recent identification of the nitric oxide synthase (NOS) pathway in various cell types in the skin has provided important insight into the molecular mechanisms underlying regulatory and homeostatic functions of the skin. Many studies also point to perturbations or defects in the signaling cascade of nitric oxide (NO) and reactive nitrogen intermediates as key players in skin disease pathogenesis. A critical role for NO is now established for a subset of human skin diseases, and new mechanism-based therapies may be available in the near future. This remarkable progress and the implications it may have for common forms of skin disease are reviewed here.

Development and Management of Severe Cutaneous Side Effects in Head-and-Neck Cancer Patients during Concurrent Radiotherapy and Cetuximab

Background:The concurrent administration of cetuximab to radiotherapy has recently been shown to improve the clinical outcome of head-and-neck cancer (HNC) patients. An aggravation of the radiation-induced skin toxicity was not described. Here, however, two cases with severe skin toxicity during the combined treatment are reported.Clinical Observations:In a small group of five patients with locally advanced HNC treated with irradiation and concurrent cetuximab, two cases of unusually severe radiation dermatitis were observed. Both patients developed confluent moist desquamations confined to the irradiation field at a dose of 40 Gy (CTC [Common Toxicity Criteria] grade 3), which progressed into an ulcerative dermatitis (grade 4) at 58 Gy and 46 Gy, respectively. Histopathology showed a vacuolic degeneration of basal keratinocytes, subepidermal blister formation, and mixed perivascular and interstitial inflammatory infiltrates leading to a complete loss of the epidermis. These cutaneous side effects led to the discontinuation of radiotherapy. Topical corticosteroids and systemic antibiotic treatment resulted in wound healing, which allowed the continuation of radiotherapy.Conclusion:These findings indicate that cetuximab may have the potential to enhance the severity of radiation dermatitis in HNC patients. A systematic monitoring of cutaneous side effects during radiotherapy plus cetuximab is advised in order to reliably estimate the frequency of severe (grade 3/4) radiation dermatitis.Hintergrund:Die simultane Applikation von Cetuximab zur Strahlentherapie verbessert nach einer kürzlich publizierten Studie die Prognose von Patienten mit Kopf-Hals-Tumoren (HNC). Hinweise auf eine Verstärkung der strahlenbedingten Hautreaktion ergaben sich nicht. Im Folgenden wird allerdings über zwei Fälle mit schwersten Hautreaktionen während der kombinierten Behandlung berichtet.Beobachtungen:In einer kleinen Gruppe von fünf Patienten mit HNC, die mit Bestrahlung und simultanem Cetuximab behandelt wurden, war bei zwei Patienten eine ungewöhnlich starke Radiodermatitis zu beobachten. Beide Patienten entwickelten während der Behandlung bei einer Dosis von 40 Gy zunächst konfluierende feuchte Epitheliolysen in den Bestrahlungsfeldern (CTC [Common Toxicity Criteria] Grad 3), welche bei einer Dosis von 58 Gy bzw. 46 Gy in ulzerative Dermatitiden übergingen (CTC Grad 4). Histopathologisch zeigten sich vakuolische Degenerationen der basalen Keratinozyten, subepidermale Blasenbildungen sowie perivaskuläre und interstitielle inflammatorische Infiltrate mit komplettem Verlust der Epidermis. Diese Nebenwirkungen führten in beiden Fällen zu einer Unterbrechung der Radiotherapie. Durch eine intensive Therapie mit topischen Glukokortikosteroiden sowie eine systemische antibiotische Behandlung kam es zur kompletten Abheilung, was die Fortsetzung der Bestrahlung ermöglichte.Schlussfolgerung:Diese Beobachtungen zeigen, dass Cetuximab das Potential haben könnte, den Grad der Radiodermatitis bei Patienten mit HNC wesentlich zu verstärken. Ein systematisches Monitoring der Hautnebenwirkungen während der Radiotherapie in Kombination mit Cetuximab ist erforderlich, um die Häufigkeit der schweren Radiodermatitis (Grad 3/4) verlässlich einschätzen zu können.

Eccrine Porocarcinoma of the Head: An Important Differential Diagnosis in the Elderly Patient

Background: Eccrine porocarcinoma is a rare malignant tumor of the sweat gland, characterized by a broad spectrum of clinicopathologic presentations. Surprisingly, unlike its benign counterpart eccrine poroma, eccrine porocarcinoma is seldom found in areas with a high density of eccrine sweat glands, like the palms or soles. Instead, eccrine porocarcinoma frequently occurs on the lower extremities, trunk and abdomen, but also on the head, resembling various other skin tumors, as illustrated in the patients described herein. Observations: We report 5 cases of eccrine porocarcinoma of the head. All patients were initially diagnosed as having epidermal or melanocytic skin tumors. Only after histopathologic examination were they classified as eccrine porocarcinoma, showing features of epithelial tumors with abortive ductal differentiation. Characteristic clinical, histopathologic and immunohistochemical findings of eccrine porocarcinomas are illustrated. Conclusion: Eccrine porocarcinomas are potentially fatal adnexal malignancies, in which extensive metastatic dissemination may occur. Porocarcinomas are commonly overlooked, or misinterpreted as squamous or basal cell carcinomas as well as other common malignant and even benign skin tumors. Knowledge of the clinical pattern and histologic findings, therefore, is crucial for an early therapeutic intervention, which can reduce the risk of tumor recurrence and serious complications.

Langerhans cells, nitric oxide, keratinocytes and psoriasis

In a recent Viewpoint article, Morhenn gave a provocative view on the role of Langerhans cells expressing inducible nitric oxide synthase (iNOS) in the pathogenesis of psoriasis1xMorhenn, V.B. Immunol. Today. 1997; 18: 433–436Abstract | Full Text PDF | PubMed | Scopus (48)See all References1. It is not surprising that this article raised an argument2xMcKenzie, R.C. and Weller, R. Immunol. Today. 1998; 19: 427Abstract | Full Text | Full Text PDF | PubMedSee all References2 because there is no direct proof for the postulated key role of iNOS-expressing Langerhans cells in this immune-mediated skin disease, whereas numerous studies demonstrate beyond doubt that epidermal keratinocytes play a key role3xBruch-Gerharz, D., Ruzicka, T., and Kolb-Bachofen, V. J. Invest. Dermatol. 1998; 110: 1–7Crossref | PubMed | Scopus (154)See all References3.In the reply to McKenzie and Weller, Morhenn cites a reference from our group4xBruch-Gerharz, D., Fehsel, K., Suschek, C., Michel, G., Ruzicka, T., and Kolb-Bachofen, V. J. Exp. Med. 1996; 184: 2007–2012Crossref | PubMedSee all References4, and suggests that we would have found iNOS-positive Langerhans cells if we had performed double staining to localize epidermal Langerhans cells5xMorhenn, V.B. Immunol. Today. 1998; 19: 427–428Abstract | Full Text | Full Text PDF | PubMedSee all References5. This is wrong on two accounts: First, we did perform careful CD1a immunostaining in serial sections as we were interested in this cell initially. Second, the majority of Langerhans cells in psoriatic lesions do not stain positive for iNOS. Furthermore, Langerhans cells are normally located in basal and lower suprabasal layers, but appear all over suprabasal areas in the lesional psoriatic skin. Therefore, it is tempting to speculate that the (majority of) Langerhans cells are actually avoiding the iNOS positive area in the epidermal layer (Fig. 1Fig. 1).Fig. 1Cryostat sections from lesional psoriatic skin were stained for inducible nitric oxide synthase (iNOS) protein (a) or for CD1a antigen (b) as a marker for Langerhans cells. As can be seen, Langerhans cells are located primarily, though not exclusively, in the iNOS negative suprabasal epidermal layers. Magnification=500×.View Large Image | Download PowerPoint SlideOf course, there could still be the one iNOS+CD1a+ cell that is decisive for the hyperproliferative process in psoriatic epidermis. A few years ago, the same argument was provided for the presence of a single specific T cell at the site of inflammatory tissue destruction. Meanwhile, most of us have accepted that immune dysregulation and innate immunity can, at least in some disease processes, contribute to a larger extent than expected. Thus, we feel it more convincing in the face of current evidence that an immune-mediated skin disease could be essentially homemade by keratinocyte-driven cytokine and NO synthesis.

Bortezomib induces erythema multiforme-like cutaneous adverse effects: report of two cases

Bortezomib is a novel anti-cancer agent used for the treatment of myeloand lymphoproliferative disorders [1, 2]. Adverse effects of bortezomib include mostly illdefined maculo-papular eruptions commonly termed “rash” [3]. Here, we report two cases of erythema multiforme (EM)-like skin eruptions associated to bortezomib. Patient 1 was a 48-year-old man who presented with a two-year history of multiple myeloma classified as subtype IgG λ (stage III A). Three days after completion of the third cycle of bortezomib therapy (1.3 mg/m2, days 1, 4, 8 and 11), the patient developed multiple transient, nonpruritic, indolent, erythematosus and edematous plaques on the neck and the upper trunk. Remarkably, some of the plaques had a cockade-like pattern with a central vesicle, resembling skin eruptions observed in erythema multiforme (EM) (Fig. 1). Patient 2 was a 79-year-old man who presented with a one-year history of multiple myeloma classified as subtype IgG κ (stage III A). The patient received a therapy with bortezomib (1.3 mg/m2, days 1, 4, 8, 11, 22, 25, 29 and 32), melphalan (9 mg/m2, days 1 to 4) and prednisolone (60 mg/m2, days 1 to 4). Similar to the first patient, three days after completion of the third cycle of bortezomib multiple indolent, erythematous and edematous, partly EM-like, centrally ulcerated plaques occured in the area of his left mandible and his back. Dermatohistopathological examinations in both patients revealed a dense, perivascular inflammatory infiltrate composed of lymphocytes and histiocytes, as well as some neutrophils and eosinophils in the upper and middle dermis. Additionally, single plasma cells and spotted extravasates of erythrocytes as well as hemosiderin deposits were found (Fig. 2). Immunohistochemical analysis including anti-CD138 did not show any specific infiltrates of the multiple myeloma (not shown). Skin eruptions resolved following systemic treatment with prednisone 40 mg daily, tapered over 12 days, or topical application of methyleprednisolone-aceponate-containing ointments, respectively. Bortezomib therapy was terminated due to the cutaneous adverse effects in both patients. At this time point both patients had achieved a partial remission according to the European Bone Marrow Transplantation (EBMT) criteria. This is of particular interest, since cutaneous adverse effects have been reported to serve as potential surrogate markers of therapy response in lymphoma patients treated with bortezomib [4]. Bortezomib induces apoptosis and growth arrest in myeloma cells by blocking inhibitory-κB (IκB) degradation and hence by preventing the activation of nuclear factor κB (NFκB) [5]. Bortezomib-associated adverse effects include peripheral neuropathy, fatigue, thrombocytopenia and gastrointestinal events [6]. Cutaneous adverse effects include mostly illdefined, diffuse maculo-papular eruptions commonly termed “rash”, described in 7 to 24 percent of the cases [3]. Pathophysiological concepts for the genesis of cutaneous adverse effects propose an induction of proinflammatory cytokines like IL-6, the C-reactive protein and notably TNF-α [3, 7, 8]. Interestingly, TNF-α has been demonstrated to be expressed in the vast majority (64 percent) of a series of drug-induced EMs, pointing towards a probable mechanism for the development of the lesions observed in our patients [9]. EM represents a severe inflammatory skin condition, that is considered to be a hypersensitivity reaction to infections or drugs and that may progress to Stevens-Johnson or Lyell’s syndrome. Due to their innocuous clinical characteristics EM-like skin lesions in patients treated with borte-

Topische Behandlung des subakut-kutanen Lupus erythematodes mit Tacrolimus

1. Grimme H, Petres A, Bergen E et al. (1999) Metastasizing porocarcinoma of the head with lethal outcome. Dermatology 198:298–300 2. Lan CCE, Yu HS, Liao WT et al. (2003) Clear cell eccrine porocarcinoma with extensive cutaneous metastasis and peripheral lymphocyte dysfunction. Br J Dermatol 149:1059–1063 3. Nemoto I, Akiyama N, Aoyagi S et al. (2004) Eccrine porocarcinoma and eccrine poroma arising in a scar. Br J Dermatol 150:1232–1233 4. Pinkus H, Mehregan AH (1963) Epidermotrophic eccrine carcinoma. Arch Dermatol 88:597–606 5. Robson A, Greene J, Ansari N et al. (2001) Eccrine porocarcinoma (malignant eccrine poroma): a clinicopathologic study of 69 cases. Am J Surg Pathol 25:710–720 6. Rütten A (2002) Ekkrine Schweißdrüsenkarzinome der Haut. Pathologe 23:79–88 7. Snow SN, Reizner GT (1992) Eccrine porocarcinoma of the face. J Am Acad Dermatol 27:306–311

Botulinumtoxinbehandlung eines ekkrinen Schweißdrüsennävus

1. Gorlin RJ, Goltz RW (1960) Multiple nevoid basalcell epithelioma, jaw cysts and bifid rib. A syndrome. N Engl J Med 262:908–911 2. Horn M, Wolf P, Wulf HC et al. (2003) Topical methyl aminolaevulinate photodynamic therapy in patients with basal cell carcinoma prone to complications and poor cosmetic outcome with conventional treatment. Br J Dermatol 149:1242–1249 3. Kimonis VE, Goldstein AM, Pastakia B et al. (1997) Clinical manifestations in 105 persons with nevoid basal cell carcinoma syndrome. Am J Med Genet 69:299–308 4. Reifenberger J (2004) Hereditary tumor syndromes. Cutaneous manifestations and molecular pathogenesis of Gorlin and Cowden syndromes. Hautarzt 55:942–945 noide aufgrund ihrer proliferationshemmenden und differenzierungsfördernden Eigenschaften eingesetzt. Aufgrund des bestehenden Kinderwunsches mussten wir bei unserer Patientin jedoch hiervon absehen. Ferner ist den Patienten ein konsequenter UV-Schutz anzuraten [4].

[Familial benign chronic pemphigus (Hailey-Hailey disease): successful treatment with carbon dioxide laser].

Hailey-Hailey disease is a rare, autosomal dominantly inherited genodermatosis, which manifests with recurrent intraepidermal blistering and erythematous hyperkeratotic patches in intertriginous areas. Conventional therapeutic approaches include topical and systemic steroids, antibiotic agents, as well as oral retinoids. Alternative treatments include surgical interventions such as excision, dermabrasion and laser ablation. A 56-year-old woman presented with 15-year history of severe therapy-resistant Hailey-Hailey disease. We performed laser ablation with carbon dioxide laser under general anesthesia. Six weeks after treatment complete remission within ablated areas was achieved. Six-month follow-up showed no relapse. In our opinion carbon dioxide laser ablation represents an effective and safe therapeutic option for Hailey-Hailey disease.