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Subject-tailored parallel transmission pulses for ultra-high fields body applications are typically calculated based on subject-specific126 channel-wise, complex, relative 2DThe deep learning-basedThe feasibility of estimating 2D relative

PURPOSE To introduce and investigate a method for free-breathing three-dimensional (3D) B1+ mapping of the human body at ultrahigh field (UHF), which can be used to generate homogenous flip angle (FA) distributions in the human body at UHF. METHODS A 3D relative B1+ mapping sequence with a radial phase-encoding (RPE) k-space trajectory was developed and applied in 11 healthy subjects at 7T. An RPE-based actual flip angle mapping method was applied with a dedicated B1+ shim setting to calibrate the relative B1+ maps yielding absolute B1+ maps of the individual transmit channels. The method was evaluated in a motion phantom and by multidimensional in vivo measurements. Additionally, 3D gradient echo scans with and without static phase-only B1+ shims were used to qualitatively validate B1+ shim predictions. RESULTS The phantom validation revealed good agreement for B1+ maps between dynamic measurement and static reference acquisition. The proposed 3D method was successfully validated in vivo by comparing magnitude and phase distributions with a 2D Cartesian reference. 3D B1+ maps free from visible motion artifacts were successfully acquired for 11 subjects with body mass indexes ranging from 19 kg/m2 to 34 kg/m2 . 3D respiration-resolved absolute B1+ maps indicated FA differences between inhalation and exhalation up to 15% for one channel and up to 24% for combined channels for shallow breathing. CONCLUSION The proposed method provides respiration-resolved absolute 3D B1+ maps of the human body at UHF, which enables the investigation and development of 3D B1+ shimming and parallel transmission methods to further enhance body imaging at UHF.

ZusammenfassungDie Hidradenitis suppurativa ist eine chronisch entzündliche Erkrankung von Terminalfollikeln und apokrinen Drüsen der Axilla. Die sichere und kosmetisch ansprechende Rekonstruktion großer Defekte nach radikaler Exzision erkrankter Areale in der Axilla stellt eine operative Herausforderung an den Chirurgen dar. Die laterale Thoraxregion bietet – neben weiteren – die Möglichkeit zur lokalen Perforatorlappenplastik, basierend auf der Arteria thoracodorsalis und der Arteria thoracica lateralis. Diese Arbeit zeigt erstmals in großer Fallzahl die Rekonstruktion axillärer Defekte durch den lateral thoracic artery perforator-Lappen. Insgesamt 13 Lappenplastiken (10 lateral thoracic artery perforator-Lappen und 3 thoracodorsal artery perforator-Lappen) wurden eingeschlossen. Die Patienten wurden im Rahmen der Nachuntersuchung auf postoperative Komplikationen nach Clavien-Dindo, das subjektive kosmetische Ergebnis, die Abduktionsfähigkeit des Arms in Form der range of motion und auf die Rezidivrate hin untersucht. Hierbei kam es weder zu einem Lappenuntergang noch zu einer Lappenteilnekrose. Bis auf einen Fall bewerteten alle Patienten das kosmetische Ergebnis als sehr gut oder gut. Die postoperative Schulterbeweglichkeit war stets uneingeschränkt mit einer maximalen Abduktionsfähigkeit von 178,8 ± 4,2° und in der postoperativen Nachuntersuchung von durchschnittlich 27,2 ± 14,4 Monaten kam es in keinem Fall zu einem Rezidiv. Die Verwendung der lokalen fasziokutanen Perforatorlappen der Arteria thoracica lateralis und Arteria thoracodorsalis zur plastisch-chirurgischen Behandlung der axillären HS im Stadium II und III führt zu guten ästhetischen und funktionellen Ergebnissen.

Purpose: Respiratory motion‐compensated (MC) 3D cardiac fat‐water imaging at 7T. Methods: Free‐breathing bipolar 3D triple‐echo gradient‐recalled‐echo (GRE) data with radial phase‐encoding (RPE) trajectory were acquired in 11 healthy volunteers (7M\4F, 21–35 years, mean: 30 years) with a wide range of body mass index (BMI; 19.9–34.0 kg/m2) and volunteer tailored B1+ shimming. The bipolar‐corrected triple‐echo GRE‐RPE data were binned into different respiratory phases (self‐navigation) and were used for the estimation of non‐rigid motion vector fields (MF) and respiratory resolved (RR) maps of the main magnetic field deviations (ΔB0). RR ΔB0 maps and MC ΔB0 maps were compared to a reference respiratory phase to assess respiration‐induced changes. Subsequently, cardiac binned fat‐water images were obtained using a model‐based, respiratory motion‐corrected image reconstruction. Results: The 3D cardiac fat‐water imaging at 7T was successfully demonstrated. Local respiration‐induced frequency shifts in MC ΔB0 maps are small compared to the chemical shifts used in the multi‐peak model. Compared to the reference exhale ΔB0 map these changes are in the order of 10 Hz on average. Cardiac binned MC fat‐water reconstruction reduced respiration induced blurring in the fat‐water images, and flow artifacts are reduced in the end‐diastolic fat‐water separated images. Conclusion: This work demonstrates the feasibility of 3D fat‐water imaging at UHF for the entire human heart despite spatial and temporal B1+ and B0 variations, as well as respiratory and cardiac motion.

Purpose MRI at ultra-high fields in the human body is highly challenging and requires lengthy calibration times to compensate for spatially heterogeneous B 1 + profiles. This study investigates the feasibility of using pre-computed universal pulses for calibration-free homogeneous 3D flip angle distribution in the human heart at 7T. Methods Twenty-two channel-wise 3D B 1 + data sets were acquired under free-breathing in 19 subjects to generate a library for an offline universal pulse (UP) design (group 1: 12 males [M] and 7 females [F], 21-66 years, 19.8-28.3 kg/m2 ). Three of these subjects (2M/1F, 21-33 years, 20.8-23.6 kg/m2 ) were re-scanned on different days. A 4kT-points UP optimized for the 22 channel-wise 3D B 1 + data sets in group 1 (UP22-4kT) is proposed and applied at 7T in 9 new and unseen subjects (group 2: 4M/5F, 25-56 years, 19.5-35.3 kg/m2 ). Multiple tailored and universal static and dynamic parallel-transmit (pTx) pulses were designed and evaluated for different permutations of the B 1 + data sets in group 1 and 2. Results The proposed UP22-4kT provides low B 1 + variation in all subjects, seen and unseen, without severe signal drops. Experimental data at 7T acquired with UP22-4kT shows comparable image quality as data acquired with tailored-4kT pulses and demonstrates successful calibration-free pTx of the human heart. Conclusion UP22-4kT allows for calibration-free homogeneous flip angle distributions across the human heart at 7T. Large inter-subject variations because of sex, age, and body mass index are well tolerated. The proposed universal pulse removes the need for lengthy (10-15 min) calibration scans and therefore has the potential to bring body imaging at 7T closer to the clinical application.

Background and Aims Macrophages and monocytes are main players in innate immunity. In renal diseases, their role is poorly understood. Our multicentric cross-sectional study aimed to study the prevalence of macrophages and monocytes in various human native kidney diseases. For this, we used precise pixel-based digital quantification of their densities in renal biopsies and correlated our findings with clinical data. Method We included 324 patients, who underwent a diagnostic renal biopsy. Additional normal kidney samples from 16 tumour nephrectomies were used as controls. According to the diagnosed diseases, we established 17 patient groups. Biopsies were stained for CD68+-macrophages using automated immunohistochemistry (Ventana Ultra) and selected groups were further subtyped for CD14+-monocytes and CD163+-M2-macrophages (67 cases, pauci-immune glomerulonephritis (PIGN), IgA-nephropathy (IgAN) and control samples). Digitized sections (Leica) were analysed using the open-source software QuPath to quantify cell densities (positively stained areas displayed as percentages of ROI) in renal cortex, medulla and extrarenal tissue, respectively. Detailed clinical and laboratory data at timepoint of biopsy were available for all patients. Additional data for follow-up were achievable in 158 cases. Results Renal disease samples presented higher mean macrophage densities compared to control cases (CD68: cortex 1.2 vs. 0.2%, p64 years) showed a higher medullary M2-infiltration (1.81% vs. 4.34%, p Conclusion Macrophages may promote progression of human renal diseases, whereas monocytes do not correlate with eGFR-decline. Especially, in cANCA- vasculitis CD163+- infiltration is associated with renal outcome. Additional studies are needed to investigate, whether macrophages can serve as predictive markers or therapeutical targets in native renal diseases.

Design, implementation, evaluation, and application of a 32-channel Self-Grounded Bow-Tie (SGBT) transceiver array for cardiac MR (CMR) at 7.0T.The array consists of 32 compact SGBT building blocks. Transmission field (The compact SGBT building block facilitates a modular high-density array that supports accelerated and high spatial resolution CMR at 7.0T. The array provides a technological basis for future clinical assessment of parallel transmission techniques.

Three-dimensional (3D) human heart imaging at ultra-high fields is highly challenging due to respiratory and cardiac motion-induced artifacts as well as spatially heterogeneous B1+ profiles. In this study, we investigate the feasibility of applying 3D flip angle (FA) homogenization targeting the whole heart via static phase-only and dynamic kT-point in vivo parallel transmission at 7 T. 3D B1+ maps of the thorax were acquired under free breathing in eight subjects to compute parallel transmission pulses that improve excitation homogeneity in the human heart. To analyze the number of kT-points required, excitation homogeneity and radiofrequency (RF) power were compared using different regions of interest in six subjects with different body mass index (BMI) values of 20-34 kg/m2 for a wide range of regularization parameters. One subset of the optimized subject-specific pulses was applied in vivo on a 7 T scanner for six subjects in Cartesian 3D breath-hold scans as well as in two subjects in a radial phase-encoded 3D free-breathing scan. Across all subjects, 3-4 kT-points achieved a good tradeoff between RF power and nominal FA homogeneity. For subjects with a BMI in the normal range, the 4 kT-point pulses reliably improved the coefficient of variation by less than 10% compared with less than 25% achieved by static phase-only parallel transmission. in vivo measurements on a 7 T scanner validated the B1+ estimations and the pulse design, despite neglecting ΔB0 in the optimizations and Bloch simulations. This study demonstrates in vivo that kT-point pTx pulses are highly suitable for mitigating nominal FA heterogeneities across the entire 3D heart volume at 7 T. Furthermore, 3-4 kT-points demonstrate a practical tradeoff between nominal FA heterogeneity mitigation and RF power.

Hidradenitis suppurativa is a chronic inflammatory disease of apocrine gland-bearing skin, especially in the axilla. The coverage of large defects in the region of the axilla after radical resection poses a challenge to reconstructive surgery. The lateral chest offers, among others, two options for perforator flaps: the thoracodorsal artery perforator flap and the lateral thoracic artery perforator flap. This article introduces the lateral thoracic artery flap as an additional option for defect restoration alongside the thoracodorsal artery perforator flap. A total of 13 flaps (10 lateral thoracic artery perforator flaps and 3 thoracodorsal artery perforator flaps) were used for defect reconstruction in 10 patients with axillary hidradenitis suppurativa stages II or III. All patients were assessed for surgical complications pursuant to the classification of Clavien-Dindo, subjective aesthetic results, recurrence rate, and maximum abduction angle evaluated by measuring the range of motion. All flaps healed without major or partial flap necrosis. In 12 out of 13 flaps, the aesthetic result was rated very good or good.Only one patient complained of a visible scar, but rated the overall result as satisfactory. The range of motion in the shoulder was unlimited in all cases with a maximum abduction angle of 178.8 ± 4.2°. Recurrence was not observed in any case during the postsurgical follow-up of 27.2 ± 14.4 months. The use of the two perforator-based fasciocutaneous flaps of the thoraco dorsal artery and the lateral thoracic artery offers a useful and reliable option for the reconstruction of large axillary defects while maintaining full shoulder movement and providing cosmetically satisfactory results.Die Hidradenitis suppurativa ist eine chronisch entzündliche Erkrankung von Terminalfollikeln und apokrinen Drüsen der Axilla. Die sichere und kosmetisch ansprechende Rekonstruktion großer Defekte nach radikaler Exzision erkrankter Areale in der Axilla stellt eine operative Herausforderung an den Chirurgen dar. Die laterale Thoraxregion bietet – neben weiteren – die Möglichkeit zur lokalen Perforatorlappenplastik, basierend auf der Arteria thoracodorsalis und der Arteria thoracica lateralis. Diese Arbeit zeigt erstmals in großer Fallzahl die Rekonstruktion axillärer Defekte durch den lateral thoracic artery perforator-Lappen. Insgesamt 13 Lappenplastiken (10 lateral thoracic artery perforator-Lappen und 3 thoracodorsal artery perforator-Lappen) wurden eingeschlossen. Die Patienten wurden im Rahmen der Nachuntersuchung auf postoperative Komplikationen nach Clavien-Dindo, das subjektive kosmetische Ergebnis, die Abduktionsfähigkeit des Arms in Form der range of motion und auf die Rezidivrate hin untersucht. Hierbei kam es weder zu einem Lappenuntergang noch zu einer Lappenteilnekrose. Bis auf einen Fall bewerteten alle Patienten das kosmetische Ergebnis als sehr gut oder gut. Die postoperative Schulterbeweglichkeit war stets uneingeschränkt mit einer maximalen Abduktionsfähigkeit von 178,8 ± 4,2° und in der postoperativen Nachuntersuchung von durchschnittlich 27,2 ± 14,4 Monaten kam es in keinem Fall zu einem Rezidiv. Die Verwendung der lokalen fasziokutanen Perforatorlappen der Arteria thoracica lateralis und Arteria thoracodorsalis zur plastisch-chirurgischen Behandlung der axillären HS im Stadium II und III führt zu guten ästhetischen und funktionellen Ergebnissen.

Background In 2016, World Health Organization guidelines conditionally recommended standardised shorter 9–12-month regimens for multidrug-resistant (MDR) tuberculosis (TB) treatment. We conducted a prospective study of a shorter standardised MDR-TB regimen in Karakalpakstan, Uzbekistan. Methods Consecutive adults and children with confirmed rifampicin-resistant pulmonary TB were enrolled between September 1, 2013 and March 31, 2015; exclusions included prior treatment with second-line anti-TB drugs, and documented resistance to ofloxacin or to two second-line injectable agents. The primary outcome was recurrence-free cure at 1 year following treatment completion. Results Of 146 enrolled patients, 128 were included: 67 female (52.3%), median age 30.1 (interquartile range 23.8–44.4) years. At the end of treatment, 71.9% (92 out of 128) of patients achieved treatment success, with 68% (87 out of 128) achieving recurrence-free cure at 1 year following completion. Unsuccessful outcomes during treatment included 22 (17.2%) treatment failures with fluoroquinolone-resistance amplification in 8 patients (8 out of 22, 36.4%); 12 (9.4%) lost to follow-up; and 2 (1.5%) deaths. Recurrence occurred in one patient. Fourteen patients (10.9%) experienced serious adverse events. Baseline resistance to both pyrazinamide and ethambutol (adjusted OR 6.13, 95% CI 2.01; 18.63) and adherence, A standardised shorter MDR-TB regimen observational study in Uzbekistan showed moderate success, but high treatment failure with significant risk of amplification of fluoroquinolone resistance https://bit.ly/3o8vfJz

Biogas, with its high carbon dioxide content (30–50 vol%), is an attractive feed for catalytic methanation with green hydrogen, and is suitable for establishing a closed carbon cycle with methane as energy carrier. The most important questions for direct biogas methanation are how the high methane content influences the methanation reaction and overall efficiency on one hand, and to what extent the methanation catalysts can be made more resistant to various sulfur-containing compounds in biogas on the other hand. Ni-based catalysts are the most favored for economic reasons. The interplay of active compounds, supports, and promoters is discussed regarding the potential for improving sulfur resistance. Several strategies are addressed and experimental studies are evaluated, to identify catalysts which might be suitable for these challenges. As several catalyst functionalities must be combined, materials with two active metals and binary oxide support seem to be the best approach to technically applicable solutions. The high methane content in biogas appears to have a measurable impact on equilibrium and therefore CO2 conversion. Depending on the initial CH4/CO2 ratio, this might lead to a product with higher methane content, and, after work-up, to a drop in-option for existing natural gas grids.

A techno-economic assessment of a novel biorefinery concept is carried out. It combines the hydrotreatment of vegetable oils (HEFA) with a power-to-gas (PTG) unit that provides the required hydrogen. Several scenarios are examined: the electricity supply for the PTG unit is varied from a grid-based supply to a renewable island solution; the hydrogen supply is varied from a PTG unit to conventional steam reforming; the utilised vegetable oil is varied from jatropha to rapeseed, palm and used cooking oil; the main product is varied from jet fuel to diesel. The HEFA-plant is assumed to process 500 kt of vegetable oil annually. In the reference scenario, jatropha oil is used as feedstock producing 227 kt a−1 of jet fuel. Per ton of processed oil, 1910 kWhel are used to produce 35.7 kg of hydrogen required for its treatment. By using different vegetable oils, both hydrogen demand and fuel output vary in a range of about ±10%. The overall energetic efficiency towards jet fuel is 41.6%. With a bandwidth between 1295 and 1800 EUR t−1 of jet fuel, the specific production costs are three to four times higher than the market price for fossil jet fuel. Operating the refinery in diesel-mode could lower the production costs by ca. 30%. More high-value, long-chained fuels are produced this way due to a lower cracking rate compared to the jet-mode. Investments of around 132 million EUR are required for the HEFA-plant in all scenarios. Investments for the PTG-plant lie around 82 million EUR if there is a constant electricity supply from the grid. They reach 246 million EUR if electricity is supplied in an island-solution based on fluctuating renewables demanding much higher hydrogen production and storage capacities. Total investments in the biorefinery reach 378 million EUR in this case. Despite high capital costs, the largest cost item is vegetable oil – similarly to a conventional HEFA plant. Supporting policy instruments such as subsidies or quotas for renewable jet fuel seem indispensable for an introduction of the PTG-HEFA technology in the short to medium term.

A sustainable way to produce plastics made from biomass (biomass to gas) and electricity (power to gas) could be obtained by the direct synthesis of light alkenes. Samples (≤ 1 g) of the bulk catalysts Co/Fe, Fe/Na/S and the supported catalysts Fe/Mn | MgO and Co | SiO2 are mentioned in the literature to allow the direct synthesis of light alkenes. These materials are studied in extended fixed beds with catalyst amounts between 35 and 70 g and classic syngas (H2 and CO) in this work in order to prepare a potential scale-up of this technology. The influence of activation conditions (H2 or CO as reduction agent; 350 or 420 °C at 1.5 bar) and synthesis temperature (230–500 °C) on catalyst activity and product selectivity are pointed out. Selectivities to ethene of up to 11% are found for Fe/Mn | MgO at T ≈ 440 °C and for Fe/Na/S at T ≈ 310 °C. The other materials did not produce significant amounts of ethene. CO2 and CH4 were the main products in any case, while C2H6 was the main C2 product. Applying CO as reduction agent was superior to activation with H2 at low times on stream (

The production of SNG from renewable sources in cases requires a dynamic and intermitted operation of the methanation reactors. This may lead to catalyst damage. Therefore, the present work is aiming at identifying restrictions and optimization approaches of the start and stop operation of fixed-bed methanation reactors. 2D modeling and simulation work is conducted and the warm start behavior of a fixed-bed reactor after 1 to 4 hours operation intermittence is analyzed. The analysis reveals the possibility for an operation interruption of up to 4 hours without high adaptation effort to restart the reactor. After approximately 4 hours the catalyst bed at the inlet part of the reactor reaches a temperature that provokes problems for a subsequent warm start.

The Katanga region in the Democratic Republic of Congo (DRC) has been struck by repeated epidemics of measles, with large outbreaks occurring in 2010–13 and 2015. In many of the affected health zones, reactive mass vaccination campaigns were conducted in response to the outbreaks. Here, we attempted to determine how effective the vaccination campaigns in 2015 were in curtailing the ongoing outbreak. We further sought to establish whether the risk of large measles outbreaks in different health zones could have been determined in advance to help prioritise areas for vaccination campaign and speed up the response. In doing so, we first attempted to identify factors that could have been used in 2015 to predict in which health zones the greatest outbreaks would occur. Administrative vaccination coverage was not a good predictor of the size of outbreaks in different health zones. Vaccination coverage derived from surveys, on the other hand, appeared to give more reliable estimates of health zones of low vaccination coverage and, consequently, large outbreaks. On a coarser geographical scale, the provinces most affected in 2015 could be predicted from the outbreak sizes in 2010–13. This, combined with the fact that the vast majority of reported cases were in under-5 year olds, would suggest that there are systematic issues of undervaccination. If this was to continue, outbreaks would be expected to continue to occur in the affected health zones at regular intervals, mostly concentrated in under-5 year olds. We further used a model of measles transmission to estimate the impact of the vaccination campaigns, by first fitting a model to the data including the campaigns and then re-running this without vaccination. We estimated the reactive campaigns to have reduced the size of the overall outbreak by approximately 21,000 (IQR: 16,000–27,000; 95% CI: 8300–38,000) cases. There was considerable heterogeneity in the impact of campaigns, with campaigns started earlier after the start of an outbreak being more impactful. Taken together, these findings suggest that while a strong routine vaccination regime remains the most effective means of measles control, it might be possible to improve the effectiveness of reactive campaigns by considering predictive factors to trigger a more targeted vaccination response.

A sensitive airborne infrared DIAL system was developed for the detection of leaks in high pressure natural gas pipelines. The system was certified according to DVGW guidelines.

Seit Jahren drängt eine neue hochqualifizierte Mitarbeitergeneration auf den Arbeitsmarkt. Ein zentrales Phänomen ihrer Prägungsphase ist dabei für das Personalmarketing von hoher Bedeutung: Die Nutzung des sozialen Webs als digitale Infrastruktur. Dieses Buch zeigt Ihnen anhand eines fünfstufigen Fahrplans, wie Unternehmen die Ansprache der Generation Internet zielgerichtet konzipieren und aufbauen können, wie man ein maßgeschneidertes Personalmarketing online und offline umsetzt und wie konkrete Marketingmaßnahmen für die neue Generation erfolgreich evaluiert werden.

CD30 is a costimulatory receptor on activated lymphocytes and a number of human lymphoma cells. Specific ligation of membrane-bound CD30 or cellular stimulation by PMA results in a metalloproteinase-mediated down-regulation of CD30 and release of its soluble ectodomain (sCD30). In this report, it is demonstrated that PMA-induced CD30 cleavage from Karpas 299 cells was mediated by a membrane-anchored metalloproteinase which was active on intact cells following 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate extraction of membrane preparations. Moreover, CD30 shedding was blocked by the synthetic hydroxamic acid-based metalloproteinase inhibitor BB-2116 (IC50, 230 nM) and the natural tissue inhibitor of metalloproteinases (TIMP)-3 (IC50, 30 nM), but not by the matrix metalloproteinase inhibitors TIMP-1 and TIMP-2. This inhibition profile is similar to that of the TNF-α- converting enzyme (TACE) and, indeed, mRNA transcripts of the membrane-bound metalloproteinase-disintegrin TACE could be detected in Karpas 299 cells. The ectodomain of TACE was expressed in bacteria as a GST fusion protein (GST-TACE) which cleaved CD30 from the surface of Karpas 299 cells and concomitantly increased the level of sCD30 in the cell supernatants. Hence, TACE does not only control the release of TNF-α, but also that of sCD30.

This works focuses on the political history of the bishopries of Bremen and Verden (North-Western Germany) during their first 300 years, beginning as unimportant mission-territories until their establishment as confident territories of the Holy German Empire in the 12th century. The second part is emphasizing on the reflection this time has found in liturgical prints during the reign of Archbishop Christoph of Brunswick, whose reign can be seen as a borderline between catholic middle ages and the beginning reformation.

In this study we analyzed the proteolytic activity of MMP-19 and its impact on keratinocyte migration. In the HaCaT keratinocyte cell line overexpressing wild-type MMP-19 (HaCaT-WT), transmigration through fibrin and type IV collagen matrices was significantly increased compared to cells harboring a catalytically inactive mutant (HaCaT-EA). Studying the expression of MMP-19 in early stages of squamous cell cancer (SCC), we found co-localization of MMP-19 and laminin 5 at the invading tumor front but not in suprabasal epidermis of the tumor. Examination of laminin 5 processing revealed increased processing of the gamma2 chain in the medium and matrix of HaCaT-WT cells and degradation by recombinant human MMP-19 to 105-kDa and 80-kDa fragments. Parental HaCaT grown on the matrix of HaCaT-WT and HaCaT-EA cells displayed differential tyrosine phosphorylation. Using integrin blocking and stimulating antibodies we could attribute these differences to a shift from beta4-integrin-dependent signaling on the HaCaT-EA matrix toward alpha3-integrin-dependent signaling on the HaCaT-WT matrix. As a consequence, parental HaCaT showed increased migration on the matrix of HaCaT-WT cells. These data suggest that the MMP-19-dependent processing of the gamma2 chains leads to the integrin switch favoring epithelial migration and that MMP-19 actively participates in the early stages of SCC invasion.

Matrix metalloproteinase 19 (MMP-19) is able to process various proteins of the basement membrane. To investigate the impact of MMP-19 activity on endothelial cells in the context of tumor extracellular matrix (ECM), we treated Matrigel matrix with an active recombinant MMP-19 and analyzed its effect on capillary-like formation. Human microvascular endothelial cells (HMEC-1) could not form capillary-like formation on Matrigel treated with recombinant MMP-19. Analyzing the Matrigel proteins, we found that MMP-19 preferentially cleaved nidogen-1. The cleavage site of nidogen-1 was mapped to Thr867-Leu868. This cleavage separates the G3 globular domain containing the binding site for the γ1 chain of laminin-1 and collagen IV and thus abolishes the capacity of nidogen-1 to cross-link ECM proteins. Anti-nidogen antibodies directed against the G3 domain of nidogen-1 inhibited the capillary-like structure formation to a similar extent as MMP-19. Since nidogen-1 is thought to stabilize microvessels, MMP-19 might be one of the enzymes that interferes with stabilization or maturation of nascent vasculature.

The novel CXC-chemokine ligand 16 (CXCL16) functions as transmembrane adhesion molecule on the surface of APCs and as a soluble chemoattractant for activated T cells. In this study, we elucidate the mechanism responsible for the conversion of the transmembrane molecule into a soluble chemokine and provide evidence for the expression and shedding of CXCL16 by fibroblasts and vascular cells. By transfection of human and murine CXCL16 in different cell lines, we show that soluble CXCL16 is constitutively generated by proteolytic cleavage of transmembrane CXCL16 resulting in reduced surface expression of the transmembrane molecule. Inhibition experiments with selective hydroxamate inhibitors against the disintegrin-like metalloproteinases a disintegrin and metalloproteinase domain (ADAM)10 and ADAM17 suggest that ADAM10, but not ADAM17, is involved in constitutive CXCL16 cleavage. In addition, the constitutive cleavage of transfected human CXCL16 was markedly reduced in embryonic fibroblasts generated from ADAM10-deficient mice. By induction of murine CXCL16 in ADAM10-deficient fibroblasts with IFN-γ and TNF-α, we show that endogenous ADAM10 is indeed involved in the release of endogenous CXCL16. Finally, the shedding of endogenous CXCL16 could be reconstituted by retransfection of ADAM10-deficient cells with ADAM10. Analyzing the expression and release of CXCXL16 by cultured vascular cells, we found that IFN-γ and TNF-α synergize to induce CXCL16 mRNA. The constitutive shedding of CXCL16 from the endothelial cell surface is blocked by inhibitors of ADAM10 and is independent of additional inhibition of ADAM17. Hence, during inflammation in the vasculature, ADAM10 may act as a CXCL16 sheddase and thereby finely control the expression and function of CXCL16 in the inflamed tissue.

Unlike most other matrix metalloproteinases (MMPs) MMP-19 is expressed in undifferentiated basal keratinocytes of healthy human skin. The human keratinocyte cell line HaCaT, which like basal keratinocytes constitutively expresses MMP-19, down-regulated the expression of MMP-19 at high calcium concentrations. Calcium-regulation occurred through E-cadherin mediated cell-cell contacts because neutralizing anti-E-cadherin antibodies restored MMP-19 expression in high calcium. Overexpression of MMP-19 in HaCaT cells (HaCaT-WT) increased cellular proliferation, as well as migration and adhesion on type I collagen. This was due to proteolysis of the insulin-like growth factor (IGF) binding protein-3 by MMP-19, which augmented signaling through the IGF-I receptor, as evidenced by its increased autophosphorylation. Conversely, these effects were not observed in cells transfected with MMP-2 or a catalytically inactive MMP-19 mutant. As further proof that increased IGF-signaling promoted adhesion and migration in HaCaT-WT cells, we reproduced these effects by treating parental HaCaT with IGF-I. We observed dephosphorylation of the focal adhesion kinase in HaCaT-WT as well as IGF-I–treated HaCaT cells, suggesting that inactivating focal adhesion kinase is a mechanism by which IGF-I enhances adhesion. Furthermore, IGF-I-triggered motility on type I collagen was mediated by MMP activity, which, however, was distinct from MMP-19. Considering the coexpression of IGFBP-3 and MMP-19 in the skin, we conclude that MMP-19 is a likely candidate to be the major IGFBP-3 degrading MMP in the quiescent epidermis. This activity might have widespread consequences for the behavior of epidermal keratinocytes.