Refine
Year of publication
Document Type
- Article (34)
Language
- English (34) (remove)
Has Fulltext
- yes (34)
Is part of the Bibliography
- no (34)
Keywords
- apoptosis (2)
- curcumin (2)
- psoriasis (2)
- 2‑methoxyestradiol (1)
- Bee venom allergy (1)
- C6 ceramide (1)
- Colorectal cancer (1)
- Hymenoptera venom allergy (1)
- Hymenoptera venom immunotherapy (1)
- Immunotherapy (1)
Institute
- Medizin (33)
- Biowissenschaften (2)
- Georg-Speyer-Haus (1)
In the basal, proliferative layer of healthy skin, the mTOR complex 1 (mTORC1) is activated, thus regulating proliferation while preventing differentiation. When cells leave the proliferative, basal compartment, mTORC1 signaling is turned off, which allows differentiation. Under inflammatory conditions, this switch is hijacked by cytokines and prevents proper differentiation. It is currently unknown how mTORC1 is regulated to mediate these effects on keratinocyte differentiation. In other tissues, mTORC1 activity is controlled through various pathways via the tuberous sclerosis complex (TSC). Thus, we investigated whether the TS complex is regulated by proinflammatory cytokines and contributes to the pathogenesis of psoriasis. TNF-α as well as IL-1β induced the phosphorylation of TSC2, especially on S939 via the PI3-K/AKT and MAPK pathway. Surprisingly, increased TSC2 phosphorylation could not be detected in psoriasis patients. Instead, TSC2 was strongly downregulated in lesional psoriatic skin compared to non-lesional skin of the same patients or healthy skin. In vitro inflammatory cytokines induced dissociation of TSC2 from the lysosome, followed by destabilization of the TS complex and degradation. Thus, we assume that in psoriasis, inflammatory cytokines induce strong TSC2 phosphorylation, which in turn leads to its degradation. Consequently, chronic mTORC1 activity impairs ordered keratinocyte differentiation and contributes to the phenotypical changes seen in the psoriatic epidermis.
Background: No simple classification system has emerged for ‘advanced basal cell carcinomas’, and more generally for all difficult-to-treat BCCs (DTT-BCCs), due to the heterogeneity of situations, TNM inappropriateness to BCCs, and different approaches of different specialists. Objective: To generate an operational classification, using the unconscious ability of experts to simplify the great heterogeneity of the clinical situations into a few relevant groups, which drive their treatment decisions. Method: Non-supervised independent and blinded clustering of real clinical cases of DTT-BCCs was used. Fourteen international experts from different specialties independently partitioned 199 patient cases considered ‘difficult to treat’ into as many clusters they want (≤10), choosing their own criteria for partitioning. Convergences and divergences between the individual partitions were analyzed using the similarity matrix, K-mean approach, and average silhouette method. Results: There was a rather consensual clustering of cases, regardless of the specialty and nationality of the experts. Mathematical analysis showed that consensus between experts was best represented by a partition of DTT-BCCs into five clusters, easily recognized a posteriori as five clear-cut patterns of clinical situations. The concept of ‘locally advanced’ did not appear consistent between experts. Conclusion: Although convergence between experts was not granted, this experiment shows that clinicians dealing with BCCs all tend to work by a similar pattern recognition based on the overall analysis of the situation. This study thus provides the first consensual classification of DTT-BCCs. This experimental approach using mathematical analysis of independent and blinded clustering of cases by experts can probably be applied to many other situations in dermatology and oncology.
Cutaneous T cell lymphomas (CTCLs) represent a heterogeneous group of T cell lymphomas that primarily affect the skin. The most frequent forms of CTCL are mycosis fungoides and Sézary syndrome. Both are characterized by frequent recurrence, developing chronic conditions and high mortality with a lack of a curative treatment. In this study, we evaluated the effect of short-chain, cell-permeable C6 Ceramide (C6Cer) on CTCL cell lines and keratinocytes. C6Cer significantly reduced cell viability of CTCL cell lines and induced cell death via apoptosis and necrosis. In contrast, primary human keratinocytes and HaCaT keratinocytes were less affected by C6Cer. Both keratinocyte cell lines showed higher expressions of ceramide catabolizing enzymes and HaCaT keratinocytes were able to metabolize C6Cer faster and more efficiently than CTCL cell lines, which might explain the observed protective effects. Along with other existing skin-directed therapies, C6Cer could be a novel well-tolerated drug for the topical treatment of CTCL.
Evaluation of 2‑methoxyestradiol serum levels as a potential prognostic marker in malignant melanoma
(2021)
Experimental findings indicated that 2‑methoxyestradiol (2‑ME), an endogenous metabolite of 17β‑estradiol, may exhibit anti‑tumorigenic properties in various types of tumour, such as melanoma and endometrial carcinoma. In patients with endometrial cancer, the serum levels of 2‑ME are decreased compared with those in healthy controls, and this finding has been associated with a poor outcome. The aim of the present study was to examine whether the serum levels of 2‑ME are decreased in patients with melanoma, and whether this decrease may be correlated with disease stage and, therefore, serve as a prognostic indicator. ELISA was used to detect serum levels of 2‑ME in patients with stage I‑IV malignant melanoma (MM). A cohort of 78 patients with MM was analysed, along with 25 healthy controls, among whom 15 were women in the second trimester of pregnancy (positive control). As expected, significantly elevated levels of serum 2‑ME were observed in pregnant control patients compared with those in patients with MM and healthy controls. There was no observed correlation between 2‑ME serum levels in patients with MM and disease stage, tumour thickness, lactate dehydrogenase or S100 calcium‑binding protein B levels. In addition, the 2‑ME levels of patients with MM did not differ significantly from those of normal healthy controls. Overall, the findings of the present study indicated that the 2‑ME serum levels in patients with MM were not decreased, and there was no correlation with early‑ or advanced‑stage disease. Therefore, in contrast to published results on endometrial cancer, endogenous serum 2‑ME levels in MM were not found to be correlated with tumour stage and did not appear to be a suitable prognostic factor in MM.
Background: No simple staging system has emerged for basal cell carcinomas (BCCs), since they do not follow the TNM process, and practitioners failed to agree on simple clinical or pathological criteria as a basis for a classification. Operational classification of BCCs is required for decision-making, trials and guidelines. Unsupervised clustering of real cases of difficult-to-treat BCCs (DTT-BCCs; part 1) has demonstrated that experts could blindly agree on a five groups classification of DTT-BCCs based on five patterns of clinical situations. Objective: Using this five patterns to generate an operational and comprehensive classification of BCCs. Method: Testing practitioner's agreement, when using the five patterns classification to ensure that it is robust enough to be used in the practice. Generating the first version of a staging system of BCCs based on pattern recognition. Results: Sixty-two physicians, including 48 practitioners and the 14 experts who participated in the generation of the five different patterns of DTT-BCCs, agreed on 90% of cases when classifying 199 DTT-BCCs cases using the five patterns classification (part 1) attesting that this classification is understandable and usable in practice. In order to cover the whole field of BCCs, these five groups of DTT-BCCs were added a group representing the huge number of easy-to-treat BCCs, for which sub-classification has little interest, and a group of very rare metastatic cases, resulting in a four-stage and seven-substage staging system of BCCs. Conclusion: A practical classification adapted to the specificities of BCCs is proposed. It is the first tumour classification based on pattern recognition of clinical situations, which proves to be consistent and usable. This EADO staging system version 1 will be improved step by step and tested as a decision tool and a prognostic instrument.
Background: An experienced life-threating anaphylactic reaction to hymenoptera venom can sustainably impair patients’ quality of life (QoL). Besides carrying emergency medication, venom-specific immunotherapy (VIT) exists as a causal treatment of allergy.
Objective: This study aimed to examine QoL, anxiety, depression, and physical and mental health in patients allergic to hymenoptera venom before and during VIT and the impact of a tolerated sting challenge (SC).
Methods: Between July 2017 and August 2017, 142 patients with venom allergy were analyzed using validated questionnaires as the: Vespid Allergy Quality for Life Questionnaire" (VQLQ-d), the "Hospital Anxiety and Depression Scale" (HADS-D) and the "Short Form 36" (SF-36). To evaluate the impact of VIT and SC on the QoL, patients were divided into 3 groups: (A) VIT and tolerated SC (n = 45), (B) VIT before carrying out SC (n = 73), and (C) therapy-naïve before VIT (n = 20). Further parameters like gender, age, insect species, and severity of the anaphylactic reaction were assessed.
Results: A significant correlation between the health-related QoL and the parameters of gender and state of treatment was seen. Especially male patients, as well as patients allergic to yellow jacket venom, benefit from a SC in terms of a significant increase in their QoL. In the total study cohort, a clear trend was observed towards a higher QoL in patients under VIT who tolerated a SC. Overall, neither the patients’ age nor the insect species exerted a relevant influence on QoL, depression or anxiety. However, women showed a lower QoL combined with higher anxiety and depression scores than men.
Conclusion: Immunotherapy leads to an improved QoL, which can be further increased by a SC. A tolerated SC conceivably reassures the patients by objectifying the treatment success. Female patients appear to have a stronger impaired QoL per se. Taken together, a SC can be performed during VIT to strengthen the patients’ QoL.
Background: Current literature is inconsistent regarding the risk of severe side effects using accelerated induction protocols in Hymenoptera venom immunotherapy (VIT). In addition, several data indicate the influence of purity grade of venom preparation on tolerability. We evaluated the safety and tolerability of ultra-rush and rush build-up protocols using purified and non-purified venom preparations. Methods: Retrospective single-center study of 581 VIT inductions (325 ultra-rush and 256 rush protocols) from 2005 to 2018 in 559 patients with bee and vespid venom allergy using aqueous purified (ALK SQ®) for ultra-rush protocol and aqueous non-purified (ALK Reless®) venom preparations for rush protocol. Results: Urticaria (8% vs. 3.1%, p = 0,013) and dose reductions (4.3% vs. 1.2%, p = 0,026) were significantly more frequent in the ultra-rush group. Overall rate of moderate-to-severe side effects (anaphylaxis ≥grade 2 according to Ring and Meβmer) was low and did not differ significantly between protocols (p = 0.105). Severe events (grade 4 anaphylaxis) were not reported. Discontinuation rate was very low in both cohorts (0.6% vs 1.2%). The higher purity grade of venom preparations in the ultra-rush cohort did not improve tolerability. The bee venom group showed a non-significant trend towards higher incidence of mild reactions (urticaria), resulting in more frequent dose reductions and antiallergic therapy. Conclusion: Rush and ultra-rush protocols show an excellent safety profile with only infrequent and mild anaphylactic reactions in bee and vespid venom allergy. Ultra-rush immunotherapy reduces the duration of the inpatient build-up phase setting and thus is viewed by the authors as preferred treatment in Hymenoptera venom allergic patients.
Hypersensitivity reactions to non‐steroidal anti‐inflammatory drugs (NSAIDs) – a retrospective study
(2020)
Background: The aim of this study was to verify the validity of clinical history and oral provocation challenges of patients with NSAID hypersensitivity and to identify safe alternatives. The COX‐2 inhibitor etoricoxib, in particular, was studied.
Patients and methods: In all, 104 patients with confirmed diagnoses of NSAID hypersensitivity treated at the Department of Dermatology, Frankfurt University Hospital, Germany between 2004 and 2012 were retrospectively studied.
Results: The medical history and hypersensitivity symptoms during oral provocation testing (OPT) largely coincided and were mostly mild to moderate. Acetylsalicylic acid (ASA) was the most frequent trigger both anamnestically (27.9 %) and during OPT (47.8 %). Etoricoxib caused the fewest reactions during OPT (4.2 %). Acetaminophen led to reactions in only 6.7 % of the cases studied although it was named more often in clinical histories (14 %).
Conclusions: OPT should be the aim whenever possible as most symptoms are mild to moderate. To distinguish between selective and cross‐hypersensitivity reactions, ASA should be part of the test protocol. Furthermore, the findings of this study indicate that etoricoxib and acetaminophen are safe treatment alternatives in case of NSAID hypersensitivity. However, these drugs should not be administered without prior OPT in an inpatient setting, as severe symptoms can occur.
Curcumin—a rhizomal phytochemical from the plant Curcuma longa—is well known to inhibit cell proliferation and to induce apoptosis in a broad range of cell lines. In previous studies we showed that combining low curcumin concentrations and subsequent ultraviolet A radiation (UVA) or VIS irradiation induced anti-proliferative and pro-apoptotic effects. There is still debate whether curcumin induces apoptosis via the extrinsic or the intrinsic pathway. To address this question, we investigated in three epithelial cell lines (HaCaT, A431, A549) whether the death receptors CD95, tumor necrosis factor (TNF)-receptor I and II are involved in apoptosis induced by light and curcumin. Cells were incubated with 0.25–0.5 µg/mL curcumin followed by irradiation with 1 J/cm2 UVA. This treatment was combined with inhibitors specific for distinct membrane-bound death receptors. After 24 h apoptosis induction was monitored by quantitative determination of cytoplasmic histone-associated-DNA-fragments. Validation of our test system showed that apoptosis induced by CH11 and TNF-α could be completely inhibited by their respective antagonists. Interestingly, apoptosis induced by curcumin/light treatment was reversed by none of the herein examined death receptor antagonists. These results indicate a mechanism of action independent from classical death receptors speaking for intrinsic activation of apoptosis. It could be speculated that a shift in cellular redox balance might prompt the pro-apoptotic processes
Background In melanoma, preclinical data suggest a possible role of polyunsaturated fatty acids inhibiting cell growth. A new target molecule for free fatty acids, the G protein-coupled receptor GPR40, was identified in melanoma cells.
Objectives The aim of this study was to investigate GPR40 expression in human melanocytic tissues and to evaluate its potential as a prognostic marker.
Methods and Results A total of 114 tissue sections of naevi, primary melanoma and melanoma metastasis were immunohistochemically stained with anti-GPR40. The staining was evaluated, using the immunoreactivity scoring system. Compared to naevi, primary melanoma and melanoma metastasis showed significantly higher levels of GPR40 (P < 0.05). In primary melanoma, GPR40 expression positively correlated with tumour thickness (P = 0.044) and AJCC level (P = 0.017) and in melanoma metastasis with AJCC level (P = 0.035). Primary melanoma patients with high levels of GPR40 had a significantly poorer overall survival (P = 0.004) and shorter disease-free survival (0.040).
Conclusion The present study identified GPR40 as a novel target molecule in melanoma. First evidence for a potential role of the receptor in tumour progression and metastases was found, and it could be demonstrated that GPR40 expression is negatively correlated with patient’s survival.
Recent studies have proven that Dimethylfumarate (DMF) has a marked anti-proliferative impact on diverse cancer entities e.g., on malignant melanoma. To explore its anti-tumorigenic potential, we examined the effects of DMF on human colon carcinoma cell lines and the underlying mechanisms of action. Human colon cancer cell line HT-29 and human colorectal carcinoma cell line T84 were treated with or without DMF. Effects of DMF on proliferation, cell cycle progression, and apoptosis were analyzed mainly by Bromodeoxyuridine (BrdU)- and Lactatdehydrogenase (LDH)-assays, caspase activation, flowcytometry, immunofluorescence, and immunoblotting. In addition, combinational treatments with radiation and chemotherapy were performed. DMF inhibits cell proliferation in both cell lines. It was shown that DMF induces a cell cycle arrest in G0/G1 phase, which is accompanied by upregulation of p21 and downregulation of cyclin D1 and Cyclin dependent kinase (CDK)4. Furthermore, upregulation of autophagy associated proteins suggests that autophagy is involved. In addition, the activation of apoptotic markers provides evidence that apoptosis is involved. Our results show that DMF supports the action of oxaliplatin in a synergetic manner and failed synergy with radiation. We demonstrated that DMF has distinct anti-tumorigenic, cell dependent effects on colon cancer cells by arresting cell cycle in G0/G1 phase as well as activating both the autophagic and apoptotic pathways and synergizes with chemotherapy.
hallmark of ageing is the redistribution of body fat. Particularly, subcutaneous fat decreases paralleled by a decrease of skin collagen I are typical for age-related skin atrophy. In this paper, we hypothesize that collagen I may be a relevant molecule stimulating the differentiation of adipose-derived stem cells (ASCs) into adipocytes augmenting subcutaneous fat. In this context lipogenesis, adiponectin, and collagen I receptor expression were determined. Freshly isolated ASCs were characterized by stemness-associated surface markers by FACS analysis and then transdifferentiated into adipocytes by specific medium supplements. Lipogenesis was evaluated using Nile Red staining and documented by fluorescence microscopy or quantitatively measured by using a multiwell spectrofluorometer. Expression of adiponectin was measured by real-time RT-PCR and in cell-free supernatants by ELISA, and expression of collagen I receptors was observed by western blot analysis. It was found that supports coated with collagen I promote cell adhesion and lipogenesis of ASCs. Interestingly, a reverse correlation to adiponectin expression was observed. Moreover, we found upregulation of the collagen receptor, discoidin domain-containing receptor 2; receptors of the integrin family were absent or downregulated. These findings indicate that collagen I is able to modulate lipogenesis and adiponectin expression and therefore may contribute to metabolic dysfunctions associated with ageing.
Exposure to locusts, which belong to the arthropod phylum, is an underestimated health problem, especially among workers in research facilities exposed to laboratory animals. We describe a rare case of an occupational immediate-type reaction to locusts with a possible cross-reactivity between desert locust (Schistocerca gregaria) and migratory locust (Locusta migratoria).
Psoriasis is a frequent and often severe inflammatory skin disease, characterized by altered epidermal homeostasis. Since we found previously that Akt/mTOR signaling is hyperactivated in psoriatic skin, we aimed at elucidating the role of aberrant mTORC1 signaling in this disease. We found that under healthy conditions mTOR signaling was shut off when keratinocytes switch from proliferation to terminal differentiation. Inflammatory cytokines (IL-1β, IL-17A, TNF-α) induced aberrant mTOR activity which led to enhanced proliferation and reduced expression of differentiation markers. Conversely, regular differentiation could be restored if mTORC1 signaling was blocked. In mice, activation of mTOR through the agonist MHY1485 also led to aberrant epidermal organization and involucrin distribution. In summary, these results not only identify mTORC1 as an important signal integrator pivotal for the cells fate to either proliferate or differentiate, but emphasize the role of inflammation-dependent mTOR activation as a psoriatic pathomechanism.
Photodynamic treatment of oral squamous cell carcinoma cells with low curcumin concentrations
(2017)
Objective: Curcumin is known for its anti-oxidative, anti-inflammatory and anti-tumorigenic qualities at concentrations ranging from 3.7µg/ml to 55µg/ml. Therefore it is pre-destined for tumour therapy. Due to high oral doses that have to be administered and the low bioavailability of curcumin new therapy concepts have to be developed. One of these therapy concepts is the combination of low curcumin concentrations and UVA or visible light. Aim of our study was to investigate the influence of this treatment regime on oral squamous cell carcinoma cells.
Materials and Methods: A human oral squamous cell carcinoma cell line (HN) was pre-incubated with low curcumin concentrations (0.01µg/ml to 1µg/ml). Thereafter cell cultures were either left un-irradiated or were irradiated either with 1J/cm2 UVA or for 5min with visible light. Quantitative analysis of proliferation, membrane integrity, oxidative potential and DNA fragmentation were done.
Results: It could be shown that low curcumin concentrations neither influenced proliferation, nor cell morphology, nor cell integrity nor apoptosis. When combining these curcumin concentrations with UVA or visible light irradiation cell proliferation as well as development of reactive oxygen species was reduced whereas DNA fragmentation was increased. Concentration as well as light entity specific effects could be observed.
Conclusions: The present findings substantiate the potential of the combination of low curcumin concentrations and light as a new therapeutic concept to increase the efficacy of curcumin in the treatment of cancer of the oral mucosa.
The mTOR (mechanistic target of rapamycin) inhibitor rapamycin has long been known for its immune suppressive properties, but it has shown limited therapeutic success when given systemically to patients with psoriasis. Recent data have shown that the mTOR pathway is hyperactivated in lesional psoriatic skin, which probably contributes to the disease by interfering with maturation of keratinocytes. This study investigated the effect of topical rapamycin treatment in an imiquimod-induced psoriatic mouse model. The disease was less severe if the mice had received rapamycin treatment. Immunohistological analysis revealed that rapamycin not only prevented the activation of mTOR signalling (P-mTOR and P-S6 levels), but almost normalized the expression of epidermal differentiation markers. In addition, the influx of innate immune cells into the draining lymph nodes was partially reduced by rapamycin treatment. These data emphasize the role of mTOR signalling in the pathogenesis of psoriasis, and support the investigation of topical mTOR inhibition as a novel anti-psoriatic strategy.
Mantle cell lymphoma (MCL) is a unique type of B-cell non-Hodgkin's lymphoma, which very rarely exhibits skin involvement. We herein describe the case of a 55-year-old woman, who initially presented with a nodular mass of the right infraorbital region. On histological analysis of the subcutaneous tissue, a diffuse neoplastic cell infiltration was identified, composed of medium‑sized lymphoid cells with irregular nuclei, which was diagnosed as MCL. The tumor cells were positive for CD5, CD20, CD79a, cyclin D1 and sex‑determining region Y-box 11, but negative for CD10 and CD23. Our patient received six cycles of R‑CHOP chemotherapy and intrathecal methotrexate as central nervous system prophylaxis. However, the patient relapsed 1 year later and was treated with two cycles of R‑DHAP and one cycle of intrathecal methotrexate. After achieving partial remission, the patient was consolidated with peripheral blood stem cell transplantation using the BEAM conditioning regime. While prior case studies suggest that skin invasion by MCL is associated with a poor prognosis, our patient remains alive almost 4 years after the initial presentation. Skin involvement as a first sign of systemic MCL is very rare and must be considered.
Elevated tumor interstitial fluid pressure (TIFP) is a prominent feature of solid tumors and hampers the transmigration of therapeutic macromolecules, for example, large monoclonal antibodies, from tumor-supplying vessels into the tumor interstitium. TIFP values of up to 40 mm Hg have been measured in experimental solid tumors using two conventional invasive techniques: the wick-in-needle and the micropuncture technique. We propose a novel noninvasive method of determining TIFP via ultrasonic investigation with scanning acoustic microscopy at 30-MHz frequency. In our experimental setup, we observed for the impedance fluctuations in the outer tumor hull of A431-vulva carcinoma–derived tumor xenograft mice. The gain dependence of signal strength was quantified, and the relaxation of tissue was calibrated with simultaneous hydrostatic pressure measurements. Signal patterns from the acoustical images were translated into TIFP curves, and a putative saturation effect was found for tumor pressures larger than 3 mm Hg. This is the first noninvasive approach to determine TIFP values in tumors. This technique can provide a potentially promising noninvasive assessment of TIFP and, therefore, can be used to determine the TIFP before treatment approach as well to measure therapeutic efficacy highlighted by lowered TFP values.
Preserving a patient’s own teeth—even in a difficult situation—is nowadays preferable to surgical intervention and therefore promotes development of suitable dental repair materials. Biodentine®, a mineral trioxide aggregate substitute, has been used to replace dentine in a bioactive and biocompatible manner in both the dental crown and the root. The aim of our study was to evaluate the influence of Biodentine® on pulp fibroblasts in vitro. For this study, one to five Biodentine® discs with a diameter of 5.1mm were incubated in DMEM. To obtain Biodentine® suspensions the media were collected and replaced with fresh medium every 24h for 4 days. Primary pulp cells were isolated from freshly extracted wisdom teeth of 20–23 year old patients and incubated with the Biodentine® suspensions. Proliferation, cell morphology, cell integrity and cell viability were monitored. To evaluate the effect of Biodentine® on collagen type I synthesis, the secretion of the N-terminal domain of pro-collagen type I (P1NP) and the release of transforming growth factor-β1 (TGF-β1) were quantified. None of the Biodentine® suspensions tested influenced cell morphology, proliferation or cell integrity. The cell viability varied slightly depending on the suspension used. However, the concentrations of P1NP of all pulp fibroblast cultures treated for 24h with the moderate to high Biodentine® concentration containing suspensions of day 1 were reduced to 5% of the control. Furthermore, a significant TGF-β1 reduction was observed after treatment with these suspensions. It could be shown that Biodentine® is biocompatible. However, dissolved particles of the moderate to high concentrated Biodentine® suspensions 24h after mixing induce a significant reduction of TGF-β1 release and reduce the secretion of collagen type I of primary pulp fibroblasts.
Background: Inflammation, angiogenesis and oxidative stress have been implicated in the pathogenesis of various vascular diseases. Recent evidence suggests that dimethylfumarate (DMF), an antiposriatic and anti-multiple sclerosis agent, possesses anti-inflammatory, anti-oxidative and anti-angiogenic properties. Here, we analyze the influence of DMF on TNF-α-induced expression of the important pro-inflammatory and pro-atherogenic chemokine MCP-1 and investigate the underlying mechanisms of this expression.
Findings: We analyzed constitutive and TNF-α-induced expression of MCP-1 in human umbilical vascular endothelial cells (HUVEC) +/− DMF treatment via enzyme-linkes immunosorbent assay (ELISA). DMF significantly inhibited the protein expression levels in a time- and concentration-dependent manner. Furthermore, MCP-1 mRNA expression was also reduced in response to DMF, as demonstrated by RT-PCR. Thus, the regulation occurs at the transcriptional level. Interestingly, DMF prolonged the TNF-α-induced p38 and JNK phosphorylation in HUVEC, as demonstrated by Western blot analysis; however, the p38 and JNK inhibitor SB203580 did not affect the DMF-conveyed suppression of TNF-α-induced MCP-1 expression. DMF suppressed the TNF-α-induced nuclear translocation and phosphorylation (Serine 536) of p65 in these cells. These results were additionally approved by p65 luciferase promoter assays. Furthermore, we found that DMF slightly inhibited the early degradation of IκBα. In addition, we verified our results using other important inflammatory cytokines such as CCL-5, PDGF-BB, GM-CSF and IL-6.
Conclusion: DMF suppresses various TNF-α-induced pro-inflammatory and pro-atherogenic cytokines/chemokines in human endothelial cells. This action is regulated by reduced p65 activity and nuclear translocation, which can be explained in part by the reduced early degradation of IκBα and more important the reduced phosphorylation of p65 at Serine 536. These effects were independent of the p38, PI3K and p42/44 signaling pathways. As a result, DMF might be suitable for treating patients with vascular diseases.
Since the domestication of the urus, 10.000 years ago, mankind utilizes bovine milk for different purposes. Besides usage as a nutrient also the external application of milk on skin has a long tradition going back to at least the ancient Aegypt with Cleopatra VII as a great exponent. In order to test whether milk has impact on skin physiology, cultures of human skin fibroblasts were exposed to commercial bovine milk. Our data show significant induction of proliferation by milk (max. 2,3-fold, EC50: 2,5% milk) without toxic effects. Surprisingly, bovine milk was identified as strong inducer of collagen 1A1 synthesis at both, the protein (4-fold, EC50: 0,09% milk) and promoter level. Regarding the underlying molecular pathways, we show functional activation of STAT6 in a p44/42 and p38-dependent manner. More upstream, we identified IGF-1 and insulin as key factors responsible for milk-induced collagen synthesis. These findings show that bovine milk contains bioactive molecules that act on human skin cells. Therefore, it is tempting to test the herein introduced concept in treatment of atrophic skin conditions induced e.g. by UV light or corticosteroids.
Background: The treatment of different skin conditions with spa waters is a long tradition dating back to at least late Hellenism. Interestingly, independent scientific examinations studying the effect of spa waters are scarce.
Objective: In the present in vitro study, we compared the effect of culture media supplemented with (a) thermal spa waters (La Roche-Posay, Avène) and (b) two natural mineral drinking waters (Heppinger, Adelholzener) on physiological parameters in HaCaT keratinocytes.
Methods: The different medium preparations were investigated with regard to cell proliferation and cell damage. Moreover, the impact on inflammation parameters with and without ultraviolet B (UVB) irradiation was examined.
Results: Two popular thermal spring waters were found to suppress cell proliferation and cell damage. Moreover, these waters reversed the induction of interleukin-6, as measured using enzyme-linked immunosorbent assay and promoter transactivation, and the formation of reactive oxygen species after UVB stimulation. Of note, the two natural mineral waters, which are distributed as drinking waters, had some effect on the above-mentioned parameters but to a lesser extent.
Conclusion: In summary, our results show that spa waters, and particularly those derived from thermal springs, reduce parameters associated with inflammation. It seems likely that trace elements such as selenium and zinc are critical for the observed effects.
Visible light is a better co-inducer of apoptosis for curcumin-treated human melanoma cells than UVA
(2013)
Curcumin attracts worldwide scientific interest due to its anti-proliferative and apoptosis inducing effects on different tumor cells at concentrations ranging from 10 to 150 µM (3.7–55 µg/ml). Unfortunately, because of a low oral bioavailability, only low and pharmacologically ineffective serum levels are achievable. In this study, an alternative treatment concept consisting of low concentration curcumin (0.2–5 µg/ml) and irradiation with UVA or visible light (VL) has been tested. The experimental results show clearly that this treatment decreases the proliferation and the viability of human melanoma cells while the cell membrane integrity remains intact. We identified the onset of apoptosis characterized by typical markers such as active caspases 8, 9 and 3 as well as DNA fragmentation accompanied by the loss of cell adhesion. The mitochondrial apoptosis signaling pathway is predominant due to an early activation of caspase-9. The present data indicate a higher efficacy of a combination of curcumin and VL than curcumin and UVA. Reduced effects as a result of light absorption by heavily pigmented skin are unlikely if VL is used. These results indicate that a combination of curcumin and light irradiation may be a useful additional therapy in the treatment of malignant disease.
Characteristically, most solid tumors exhibit an increased tumor interstitial fluid pressure (TIFP) that directly contributes to the lowered uptake of macromolecular therapeutics into the tumor interstitium. Abnormalities in the tumor-associated lymph vessels are a central brick in the development and prolonged sustaining of an increased TIFP. In the current study, vascular endothelial growth factor C (VEGF-C) was used to enhance tumor-associated lymphangiogenesis as a new mechanism to actively reduce the TIFP by increased lymphatic drainage of the tumor tissue. Human A431 epidermoid vulva carcinoma cells were inoculated in NMRI nu/nu mice to generate a xenograft mouse model. Seven days after tumor cell injection, VEGF-C was peritumorally injected to induce lymphangiogenesis. Tumor growth and TIFP was lowered significantly over time in VEGF-C-treated tumors in comparison to control or VEGF-A-treated animals. These data demonstrate for the first time that actively induced lymphangiogenesis can lower the TIFP in a xenograft tumor model and apparently reduce tumor growth. This model represents a novel approach to modulate biomechanical properties of the tumor interstitium enabling a lowering of TIFP in vivo.
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that are implicated in the regulation of lipid and glucose homeostasis. PPAR agonists have been shown to control inflammatory processes, in part by inhibiting distinct proinflammatory genes (e.g. Il-1β and IFN-γ). IL-8 is a member of the proinflammatory chemokine family that is important for various functions, such as mediating the adhesion of eosinophilic granulocytes onto endothelial cells. The influence of PPARδ activators on the expression of IL-8 in noninduced quiescent endothelial cells is unclear. Therefore, we explored the influence of PPARδ activators on the expression of IL-8 in nonstimulated endothelial cells. PPARδ agonists induce IL-8 expression in human umbilical vein endothelial cells. This induction is demonstrated at the level of both protein and mRNA expression. Transcriptional activation studies using IL-8 reporter gene constructs and DNA binding assays revealed that PPARδ agonists mediated their effects via an NFκB binding site. It is well known that IL-8 is also regulated by mRNA stability. To provide further evidence for this concept, we performed mRNA stability assays and found that PPARδ agonists induce the mRNA stability of IL-8. In addition, we showed that PPARδ agonists induce the phosphorylation of ERK1/2 and p38, which are known to be involved in the increase of mRNA stability. The inhibition of these MAPK signaling pathways resulted in a significant suppression of the induced IL-8 expression and the reduced mRNA stability. Therefore, our data provide the first evidence that PPARδ induces IL-8 expression in nonstimulated endothelial cells via transcriptional as well as posttranscriptional mechanisms.
Oligonucleotides suppress PKB/Akt and act as superinductors of apoptosis in human keratinocytes
(2009)
DNA oligonucleotides (ODN) applied to an organism are known to modulate the innate and adaptive immune system. Previous studies showed that a CpG-containing ODN (CpG-1-PTO) and interestingly, also a non-CpG-containing ODN (nCpG- 5-PTO) suppress inflammatory markers in skin. In the present study it was investigated whether these molecules also influence cell apoptosis. Here we show that CpG-1-PTO, nCpG-5-PTO, and also natural DNA suppress the phosphorylation of PKB/Akt in a cell-type-specific manner. Interestingly, only epithelial cells of the skin (normal human keratinocytes, HaCaT and A-431) show a suppression of PKB/Akt. This suppressive effect depends from ODN lengths, sequence and backbone. Moreover, it was found that TGFa-induced levels of PKB/Akt and EGFR were suppressed by the ODN tested. We hypothesize that this suppression might facilitate programmed cell death. By testing this hypothesis we found an increase of apoptosis markers (caspase 3/7, 8, 9, cytosolic cytochrome c, histone associated DNA fragments, apoptotic bodies) when cells were treated with ODN in combination with low doses of staurosporin, a wellknown pro-apoptotic stimulus. In summary the present data demonstrate DNA as a modulator of apoptosis which specifically targets skin epithelial cells.
High tumor interstitial fluid pressure (TIFP) is a characteristic of most solid tumors. TIFP may hamper adequate uptake of macromolecular therapeutics in tumor tissue. In addition, TIFP generates mechanical forces affecting the tumor cortex, which might influence the growth parameters of tumor cells. This seems likely as, in other tissues (namely, blood vessels or the skin), mechanical stretch is known to trigger proliferation. Therefore, we hypothesize that TIFP-induced stretch modulates proliferation-associated parameters. Solid epithelial tumors (A431 and A549) were grown in Naval Medical Research Institute nude mice, generating a TIFP of about 10 mm Hg (A431) or 5 mm Hg (A549). Tumor drainage of the central cystic area led to a rapid decline of TIFP, together with visible relaxation of the tumor cortex. It was found by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis that TIFP lowering yields a decreased phosphorylation of proliferation-associated p44/42 mitogen-activated protein kinase and tumor relaxation. In confirmation, immunohistochemical staining showed a decrease of tumor-associated proliferation marker Ki-67 after TIFP lowering. These data suggest that the mechanical stretch induced by TIFP is a positive modulator of tumor proliferation.
Mechanical stress is known to modulate fundamental events such as cell life and death. Mechanical stretch in particular has been identified as a positive regulator of proliferation in skin keratinocytes and other cell systems. In the present study it was investigated whether antiapoptotic signaling is also stimulated by mechanical stretch. It was demonstrated that mechanical stretch rapidly induced the phosphorylation of the proto-oncogene protein kinase B (PKB)/Akt at both phosphorylation sites (serine 473/threonine 308) in different epithelial cells (HaCaT, A-431, and human embryonic kidney-293). Blocking of phosphoinositide 3-OH kinase by selective inhibitors (LY-294002 and wortmannin) abrogated the stretch-induced PKB/Akt phosphorylation. Furthermore mechanical stretch stimulated phosphorylation of epidermal growth factor receptor (EGFR) and the formation of EGFR membrane clusters. Functional blocking of EGFR phosphorylation by either selective inhibitors (AG1478 and PD168393) or dominant-negative expression suppressed stretch-induced PKB/Akt phosphorylation. Finally, the angiotensin II type 1 receptor (AT1-R) was shown to induce positive transactivation of EGFR in response to cell stretch. These findings define a novel signaling pathway of mechanical stretch, namely the activation of PKB/Akt by transactivation of EGFR via angiotensin II type 1 receptor. Evidence is provided that stretch-induced activation of PKB/Akt protects cells against induced apoptosis.
Colorectal carcinoma (CRC) is a major cause of morbidity and mortality in Western countries. It has so far been molecularly defined mainly by alterations of the Wnt pathway. We show here for the first time that aberrant activities of the signal transducer and activator of transcription STAT3 actively contribute to this malignancy and, thus, are a potential therapeutic target for CRC. Constitutive STAT3 activity was found to be abundant in dedifferentiated cancer cells and infiltrating lymphocytes of CRC samples, but not in non-neoplastic colon epithelium. Cell lines derived from malignant colorectal tumors lost persistent STAT3 activity in culture. However, implantation of colon carcinoma cells into nude mice resulted in restoration of STAT3 activity, suggesting a role of an extracellular stimulus within the tumor microenvironment as a trigger for STAT activation. STAT3 activity in CRC cells triggered through interleukin-6 or through a constitutively active STAT3 mutant promoted cancer cell multiplication, whereas STAT3 inhibition through a dominant-negative variant impaired IL-6-driven proliferation. Blockade of STAT3 activation in CRCderived xenograft tumors slowed down their development, arguing for a contribution of STAT3 to colorectal tumor growth.