Proteasome-dependent protein quality control of the peroxisomal membrane protein Pxa1p.

Peroxisomes are eukaryotic organelles that function in numerous metabolic pathways and defects in peroxisome function can cause serious developmental brain disorders such as adrenoleukodystrophy (ALD). Peroxisomal membrane proteins (PMPs) play a crucial role in regulating peroxisome function. Therefore, PMP homeostasis is vital for peroxisome function. Recently, we established that certain PMPs are degraded by the Ubiquitin Proteasome System yet little is known about how faulty/non-functional PMPs undergo quality control. Here we have investigated the degradation of Pxa1p, a fatty acid transporter in the yeast Saccharomyces cerevisiae. Pxa1p is a homologue of the human protein ALDP and mutations in ALDP result in the severe disorder ALD. By introducing two corresponding ALDP mutations into Pxa1p (Pxa1MUT), fused to mGFP, we show that Pxa1MUT-mGFP is rapidly degraded from peroxisomes in a proteasome-dependent manner, while wild type Pxa1-mGFP remains relatively stable. Furthermore, we identify a role for the ubiquitin ligase Ufd4p in Pxa1MUT-mGFP degradation. Finally, we establish that inhibiting Pxa1MUT-mGFP degradation results in a partial rescue of Pxa1p activity in cells. Together, our data demonstrate that faulty PMPs can undergo proteasome-dependent quality control. Furthermore, our observations may provide new insights into the role of ALDP degradation in ALD.

[Systemic treatment of vitiligo : Balance and current developments]. / Systemtherapie der Vitiligo : Bilanz und aktuelle Entwicklungen.

Systemic drug treatment of vitiligo is currently limited to predominantly adjuvant measures for increasing the effectiveness of UV light therapy. We here present new approaches for the systemic treatment of vitiligo currently under clinical investigation. These include the α­MSH-analogue afamelatonide and oral immunosuppressants such as the Janus kinase (JAK) inhibitors which target interferon-α-dependent autotoxic inflammatory reactions. In 2015 the first publications on the successful systemic use of Janus kinase (JAK) inhibitors in vitiligo appeared. The effectiveness was experimentally supported by animal models of vitiligo and by the characterization of new biomarkers in the serum of vitiligo patients. This may significantly expand the range of treatment options for vitiligo. Topical antiinflammatory and UV therapies are still the main components of vitiligo treatment, often in combination. The main outcome parameters include the extent and duration of repigmentation, cessation of spreading, avoidance of side effects and improvement in the quality of life of patients.

[Oculocutaneous and ocular albinism]. / Okulokutaner und okulärer Albinismus.

Albinism can be divided into oculocutaneous albinism (OCA) and ocular albinism (OA). In the differential diagnostics these can be distinguished from rarer syndromes with partial albinism, which are frequently associated with susceptibility to infections and neurological symptoms. The OCA is an autosomal recessive inherited disease of melanin biosynthesis, which leads to complete or partial loss of melanin in the skin, hair follicles and eyes. Of the seven currently known subtypes (OCA 1-7), four are well-characterized (OCA 1-4). These are based on gene mutations, which code for tyrosinase, a key enzyme in melanin synthesis and for further proteins. These play an important role in the catalytic activity of tyrosinase and the structure and function of melanosomes. In the presence of these subtypes, the clinical symptoms and the course of the disease show a pronounced variability, especially in the type and extent of pigmentation of the skin and hair as well as the severity of eye involvement, which makes the phenotypic classification difficult. Treatment priorities are a consistent protection from UV light for prophylaxis against skin cancer and regular preventive investigations. The ocular alterations typical for albinism necessitate timely diagnostics and care by institutions specialized in ophthalmology. Novel strategies for systemic treatment of subtypes of albinism are in preclinical testing. The OA without skin involvement shows X­linked inheritance, is much rarer and is characterized by reduced pigmentation of the retina and iris, nystagmus and macular hypoplasia, sometimes with substantial loss of visual acuity. The typical ocular symptoms of OA can be manifested to a varying extent in all forms of OCA.

[Treatment of vitiligo]. / Therapie der Vitiligo.

The range of treatment options for vitiligo has significantly expanded in the last 10 years and we can offer our patients more effective treatment strategies supported by European guidelines and consensus findings. Topical and UV therapy are-often in combination-the main components of vitiligo treatment. The main outcome parameters include extent and maintenance of gained repigmentation, cessation of spreading, avoidance of side effects and the influence of the treatment on the quality of life. The efficacy of the currently available treatments is often limited. New options include antioxidative or melanocyte-stimulating adjuvant therapies in combination with UV or laser light as well as a topical maintenance treatment to reduce the risk of recurrences. In many cases, psychological support is indicated.

[Vitiligo: Clinical presentation and pathogenesis]. / Vitiligo : Klinik und Pathogenese.

BACKGROUND: Vitiligo is a chronic skin disorder with depigmentation of circumscribed areas due to structural and functional damage to melanocytes. RESULTS: There is international consensus on the classification in nonsegmental and segmental vitiligo. The influence of vitiligo on the quality of life is significant and is influenced by ethnic and sociocultural factors. There is a new insight into the genetic susceptibility, mechanisms and targets of the autoimmune inflammation, the altered morphology and function of melanocytes and into the association of vitiligo with other autoimmune diseases, skin cancer and skin cancer therapy. CONCLUSIONS: The recognition of associated autoimmune disorders is as important as is the assessment of changes in the quality of life. New insight into the pathogenesis may have therapeutic consequences. The relationship between vitiligo and skin cancer and between vitiligo and immunotherapies in patients with metastatic melanoma warrants close clinical monitoring of affected patients and further scientific studies.

[Skin disorders in malignant hematologic diseases]. / Hautveränderungen bei malignen hämatologischen Erkrankungen.

Numerous cutaneous manifestations have been reported in patients with hematologic malignancies. This review provides an overview on this subject by dividing skin lesions into three main groups: (1) skin disorders due to vascular changes (dilatation, occlusion and inflammation), (2) unspecific (e.g. paleness, opportunistic infections) and specific skin lesions (e.g. leukemia cutis), and (3) the large group of paraneoplastic skin disorders. Emphasis is placed on clinical findings and therapeutic options of those paraneoplastic syndromes that are most frequently found in hematologic malignancies.

Ultraviolet exposure and risk of melanoma and basal cell carcinoma in Ulm and Dresden, Germany.

BACKGROUND: There is a perpetuating increase in melanoma and basal cell carcinoma (BCC) incidence in Europe. Few studies are evaluating various risk factors for both tumours. OBJECTIVES: This pre-planned additional analysis directly compared occupational and past-time ultraviolet exposure behaviour, and examined the effects of sun sensitivity between melanoma and sporadic BCC, and assessed its importance for the two entities. PATIENTS/METHODS: The study included 503 patients (melanoma, n = 291 and BCC, n = 212), and 329 controls from Germany. In all, 244 (49%) of the cases and 165 (50%) of the controls were male (median age melanoma, 55 years; BCC, 69 years; and controls, 57 years). Selection of important risk factors was performed by backward elimination in a polytomous logistic regression. RESULTS: When directly comparing melanoma and sporadic BCC, actinic elastosis (OR 48.83; 95% CI 17.87, 133.40) and site were associated with a higher risk of melanoma, whereas mountaineering in childhood, sunburn 20 years before diagnosis, farming full time, sunbed use in general, seborrheic keratosis, actinic cheilitis, actinic keratosis and age were associated with a higher risk of sporadic BCC. Gardening 20 years before melanoma, hair colour and solar lentigo were risk factors for both entities. A re-evaluation of the data excluding lentiginous melanoma entities (i.e. acro-lentiginous and lentigo-maligna melanoma) resulted in selection of the same factors. However, compared to controls, atopy evolved as a protective factor for melanoma (OR 0.29; 95% CI 0.15, 0.57) and BCC (OR 0.41; 95% CI 0.17, 0.99), respectively, but was associated with a higher risk of sporadic BCC compared to melanoma. CONCLUSION: The odds for having clinical actinic elastosis was lower in BCC compared to melanoma. In contrast, various factors associated with chronic UV exposure and age had higher odds for sporadic BCC, rather than melanoma. Further research is required to set the context for these findings, especially regarding, atopy in non-lentiginous vs. lentiginous forms of melanoma, and possible molecular pathways involved.

Validation of Dermaphot(®) for the assessment of steroid-induced skin atrophy.

Currently, there are no accurate and simple methods available to measure this risk of atrophy in patients treated with topical glucocorticosteroids. In the present clinical trial, we validated a new score (Dermaphot(®) score) to assess the atrophogenic potential of glucocorticosteroids. 36 healthy adult volunteers were included in an investigator-initiated, blinded, randomized, intra-individual comparison, vehicle controlled multi-centre study. Subjects were treated in a randomized manner for 3 weeks with pimecrolimus cream 1 %, mometasone furoate (1 mg/g), clobetasol propionate 0.05 % and vehicle. In addition, ultrasound examination for skin thickness was performed. Data demonstrated a direct correlation of the achieved Dermaphot(®) score and the ultrasound thickness measurements. Our study shows that the Dermaphot(®) score can be used as a simple method to evaluate the atrophogenic potential of glucocorticosteroids. Respectively, we showed that the new score is an easy, valid and sensitive new tool for early detecting and quantifying even subclinical glucocorticosteroid-induced skin damage. We demonstrated that the score is able to differentiate the extent of skin atrophy (damage) after 3 weeks of topical glucocorticosteroid application with different levels of skin transparency and levels of telangiectasia.

[A decade of biologics in dermatology]. / Zehn Jahre Biologics in der Dermatologie.

Basic research on psoriasis has identified a number of molecular targets which can be of therapeutic interest. While the first two biologics--alefacept and efalizumab--were developed primarily for dermatologists, other agents like cytokine antagonists (TNFα antagonists) were introduced primarily by other medical fields. Knowledge has provided new impulses for research, so that today many therapeutic strategies are being developed, not exclusively limited to biologics. Others branches of dermatology also have benefitted greatly from biologics like ipilimumab or omalizumab.

Up-regulation of CCL11 and CCL26 is associated with activated eosinophils in bullous pemphigoid.

Eosinophils contribute to the pathogenesis of bullous pemphigoid (BP) by secretion of proinflammatory cytokines and proteases. Trafficking of eosinophils into tissue in animal models and asthma depends on interleukin-5 and a family of chemokines named eotaxins, comprising CCL11, CCL24 and CCL26. Up-regulation of CCL11 has been described in BP, but the expression of the other two members of the eotaxin-family, CCL24 and CCL26, has not been investigated. In addition to these chemokines, expression of adhesion molecules associated with eosinophil migration to the skin should be analysed. We demonstrate that similar to CCL11, the concentration of CCL26 was up-regulated in serum and blister fluid of BP patients. In contrast, the concentration of CCL24 was not elevated in sera and blister fluid of the same BP patients. In lesional skin, CCL11 and CCL26 were detected in epidermis and dermis by immunohistochemistry. In contrast to CCL11, CCL26 was expressed strongly by endothelial cells. In line with these findings, eosinophils represented the dominating cell population in BP lesional skin outnumbering other leucocytes. The percentage of eosinophils expressing very late antigen (VLA): VLA-4 (CD49d) and CD11c correlated with their quantity in tissue. Macrophage antigen (MAC)-1 (CD11b/CD18) was expressed constitutively by tissue eosinophils. In conclusion, these data link the up-regulation of the eosinophil chemotactic factor CCL26 in BP to the lesional accumulation of activated eosinophils in the skin. Thereby they broaden the understanding of BP pathogenesis and might indicate new options for therapeutic intervention.

Response of HIV-infected patients with syphilis to therapy with penicillin or intravenous ceftriaxone.

BACKGROUND: Ceftriaxone is commonly used as an alternative antibiotic drug in treating syphilis but clinical data on its efficacy are limited. OBJECTIVE: To evaluate the response of HIV-infected patients with active syphilis to treatment with penicillin or ceftriaxone. - METHODS: A retrospective study involving 24 consecutive patients with a positive Veneral Disease Research Laboratory test (VDRL) and at least one specific treponemal test. 12 patients were treated with different regimens of high-dose penicillin G for at least 2 weeks. Another 12 patients were treated with ceftriaxone 1-2g per day intravenously for 10-21 days. - RESULTS: After a median follow up of 18,3 months all patients of the penicillin-treated group and 11 of 12 ceftriaxone-treated patients showed a ≥ 4-fold decline in VDRL-titers; 91% of them already within 6 months after therapy. - CONCLUSION: Our serological data demonstrate a comparable efficacy of currently recommened penicillin and ceftriaxone treatment regimens for active syphilis in HIV-infected patients.

[Seborrheic dermatitis]. / Seborrhoisches Ekzem.

Seborrheic dermatitis is a frequent skin disorder in infancy and adulthood. It also often occurs in patients with HIV or neurologic disorders like Parkinson disease or mood disorders. It is characterized by greasy, yellow flakes or scales in areas of high sebaceous gland activity like the scalp, face, chest and upper back. Additionally, erythema and itching can be present. The etiology and pathogenesis of seborrheic dermatitis is unknown; however, the focus lies on the involvement of Malassezia yeasts or fatty acid metabolites of Malassezia, on hormones and immunologic factors. The diagnosis is usually a clinical one, based on history and the appearance and site of lesions. The therapy consists mainly of antifungal agents, corticosteroids, immunomodulators, and keratolytics. Because of the chronicity of the illness with frequent relapses, a treatment strategy in which effectiveness and potential side effects are weighed should be used.