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  • 1
    ISSN: 1600-0625
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Keratinocyte activation comprises changes in protein and gene expression pattern resulting in phenotypic and functional changes necessary for re-epithelialization such as the expression of urokinase-type plasminogen activator (uPA) and its cell surface receptor (uPA-R; CD87). As uPA and uPA-R are rapidly induced after dispase-mediated detachment of cultured normal human epidermal keratinocytes (NHEK) we hypothesized that dispase-mediated detachment may cause a similar “activation” of keratinocytes with uPA and uPA-R being only one aspect of a complex “activation reaction”. To test this hypothesis we have comparatively analysed adherent versus detached keratinocyte sheets for selected indicators of keratinocyte activation by immunohistochemistry. Furthermore we have identified genes via subtraction cloning which are up-regulated upon dispase-induced detachment. The analyses provided evidence for an increased transcriptional and translational activity in detached keratinocytes, as indicated by over-expression of several ribosomal components (L3 and S10 ribosomal protein) and transcription factors (initiation factor 4A, elongation factor 1α). Increased proliferative activity was indicated by increased expression of the proliferation markers Ki67, keratin 6 and keratin 17. Finally, several markers of keratinocyte activation such as the integrin chain αv, psoriasin, glutathion-S-transferase and heparin-binding epidermal growth factor-like growth factor were up-regulated. Furthermore mevalonate kinase, a molecule as yet unknown to be expressed in keratinocytes, was identified. The findings provide evidence that dispase-mediated detachment in cultured keratinocytes induces a reaction, which comprises the up-regulation of a complex array of proliferation- and migration-related molecules. The pattern of which resembles the activation reaction observed in the re-epithelializing keratinocytes in vivo.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 134 (1996), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Under certain pathophysiological conditions epidermal keratinocytes produce urokinase-type plasminogen activator (LIPA) or tissue-type PA (tPA). These PAs are subject to regulation by PA inhibitors (PAI). including PAl type-2 (PAI-2). In the normal epidermis. PAI-2 is present in the differentiating suprabasal layers, albeit in the apparent absence of PAs. It has, therefore, been suggested that PAI-2 plays a role in epidermal differentiation not linked to its ability lo inhibit PAs. In line with this hypothesis, we have studied, by immunohistochemistry. the distribution of PAI-2. uPA and tPA in the normal and in the lesional epidermis of patients with lupus erythematosus (LE). a disease in which epidermal differentiation is disturbed. The PAI-2 antigen was detectable in the normal epidermis and in the lesional epidermis of LE. In the normal epidermis, the PAI-2 antigen was most pronounced in the granular layer. In the hyperkeratotic epidermal lesions of LE. the PAI-2 antigen was increased. In normal and lesional skin. PAI-2 was distributed along the cell periphery. Indicating its association with the cornified envelope. Neither uPA nor tPA was detectable in normal or lesional epidermis. Our findings show that PAI-2 is a major type of PAI in normal epidermis and in the lesional epidermis of LE, and that increased epidermal PAI-2 is observed in a disease which is not associated with an increase in epidermal PAs. The data support the hypothesis that epidermal PAI-2 may have other functions than the regulation of PA activity.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 117 (1987), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: To study the organization of the plasminogen activator/plasminogen-plasmin (PA/PG-P) system in human epidermis we raised monoclonal antibodies with specificity for human plasminogen and plasmin (PG-P), Monoclonal antibody P2, which appeared most suitable for immunohistology, is a mouse monoclonal antibody of IgG1 subtype, specific for the precursor enzyme plasminogen and for the high molecular weight chain of the active enzyme, plasmin. Immunofluorescence analysis of normal human epidermis revealed that reactivity with P2 was confined to the basal cell layer. In psoriatic lesions, however, this regional organization was not found. Immunoreactivity in this case was scattered throughout all the hyperproliferating cell layers, which is taken as evidence for an altered distribution of PG-P in psoriatic lesions. In psoriasis other components of the PA/PG-P system have previously been found to be altered. In this context our findings add to the hypothesis that this system may be involved in the pathology or the pathogenesis of psoriatic lesions.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 280 (1988), S. 93-96 
    ISSN: 1432-069X
    Keywords: α2-Macroglobulin ; Monoclonal antibodies ; Immunohistochemistry ; ELISA ; Blister fluid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Monoclonal antibodies recognizing the antiproteolytic compound α2-macroglobulin (MG) were used for immunohistological studies on normal human skin. MG-specific immunoreactivity was found to be localized to the papillary dermis and to be concentrated in the region of the epidermodermal junction. In view of these findings and the possible involvement of proteolytic enzymes and their inhibitors in blister formation, we asked whether MG occurs in the fluid of experimentally induced blisters. MG was identified (by western-blotting) and quantified (by a monoclonal antibody based enzyme immunoassay) in the fluid of experimentally induced suction blisters. Taken together, MG is present in such blister fluid in concentrations 6 times lower than in serum, but still in an antiproteolytic range. These findings allow suggestion of a possible role for the antiproteolytic compound MG in blister formation.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-069X
    Keywords: Key words E.C. 3.4.21.31 ; Normal human epidermal ; keratinocytes ; HaCaT ; Ha-ras
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 288 (1996), S. 122-128 
    ISSN: 1432-069X
    Keywords: Key words Plasminogen activator system ; Plasminogen activator inhibitor type-2 ; α2-Antiplasmin ; Wound healing ; Granulation tissue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Mechanical injury of tissues is followed by the formation of a provisional fibrin matrix, which is later replaced by granulation tissue. The fibrinolytic proteinase, plasmin, is thought to contribute to the displacement of the primary matrix. Plasmin is generated from the ubiquitous proenzyme plasminogen by plasminogen activators. The system of plasminogen activation is controlled at several levels: plasminogen activator inhibitors (PAI-1 and PAI-2) counteract the activity of plasminogen activators and α 2 -antiplasmin inhibits the activity of plasmin. In order to elucidate the mechanisms that regulate the plasminogen activator system in healing human skin wounds, we performed the immunohistological study reported here. The plasmin inhibitor α 2 -antiplasmin and PAI-2 were found in the primary fibrin-rich matrix and in the granulation tissue. α 2 -Antiplasmin was diffusely distributed in the tissue and its distribution correlated with the presence and localization of plasmin(ogen) except that, in contrast to plasmin(ogen), the α 2 -antiplasmin was apparently not cell-associated. The stainings for PAI-2 increased with time and paralleled the development of the cellular infiltrate. PAI-2 was found in association with cells, which were identified by double immunofluorescence stainings as monocytes/macrophages and fibroblasts. In line with the immunohistological data, polymerase chain reaction after reverse transcription revealed mRNA for PAI-2 in healing human skin wounds. Taken together, our findings indicate that in healing human skin wounds, PAI-2 is the primary regulator of plasminogen activators, whereas α 2 -antiplasmin may serve to control plasmin activity.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 288 (1996), S. 554-558 
    ISSN: 1432-069X
    Keywords: Key words Interleukin-1 beta ; Tissue-type ; plasminogen activator ; Inflammation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Human keratinocytes synthesize and secrete tissue-type plasminogen activator (tPA). tPA converts the inactive precursor enzyme plasminogen into the trypsin-like proteinase plasmin. tPA is not found in normal epidermis, but in lesional epidermis from patients with a variety of cutaneous diseases, including psoriasis, pemphigus and pemphigoid. The presence of tPA is probably a reaction to the disease process rather than the initiating event in these etiologically and histopathologically diverse lesions. However, the factor(s) that upregulate tPA expression and secretion in keratinocytes have remained largely elusive. We sought to determine whether the inflammatory cytokine interleukin-1β (IL-1β), which is commonly present in diverse epidermal lesions, influences tPA production. Accordingly, we studied the influence of IL-1β on secretion of tPA by cells of the human keratinocyte cell line HaCaT. We found that IL-1β increased tPA secretion in these cells. Given the observation that IL-1β is a common proinflammatory mediator in cutaneous diseases, our findings may explain the increase in tPA in clinically and etiologically diverse inflammatory epidermal lesions.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 284 (1993), S. 432-439 
    ISSN: 1432-069X
    Keywords: Pemphigus ; Skin blister fluid ; Plasminogen activators ; Plasmin activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Zymographic and immunological studies revealed that primarily tissue-type plasminogen activator and to a lesser extent urokinase-type plasminogen activator were present in fluids of pemphigus vulgaris (type Neumann) skin blisters. Furthermore, plasmin activity was detected in pemphigus blister fluids using chromogenic peptide substrate assays. In pemphigus, but not in control, suction blister fluids plasmin/α2-antiplasmin and plasmin/ α2-macroglobulin complexes were found by immunoprecipitation or by testing in immunoassays after fractionation by molecular-sieve chromatography. Plasmin activity, detected by a low molecular weight chromogenic peptide assay, was ascribed to plasmin/α2-macroglobulin complexes. Since formation of plasmin/inhibitor complexes requires active plasmin, the finding indicates previous activation of plasminogen in pemphigus lesions.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1439-0973
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung EinBorrelia garinii Isolat (NE11H) wurde aus der Hämolymphe nicht gefütterterIxodes ricinus Zecken gewonnen. NE11H exprimierte vier Hauptproteine mit einem Molekulargewicht von jeweils 33, 32, 23 und 22 kDa. Im Laufe derin vitro Kultur entstand eine Variante (NE11Hp15), die durch den Verlust der 22 und 23 kDa Proteine gekennzeichnet war. NE11Hp15 zeigte keine Reaktion mit einem Immunserum gegen OspC. Wurde NE11Hp15 in Zecken passagiert, fand sich wieder eine Reaktion mit dem anti-OspC-Immunserum. Ein Klon der Ausgangslinie NE11H (cNE11H) war durch das Fehlen des 22 kDa, nicht jedoch des 23 kDa Proteins, gekennzeichnet. Das 23 kDa Protein von cNE11H wurde durch anti-OspC-Immunserum erkannt. Sowohl NE11Hp15 als auch cNE11H waren nicht in der Lage, eine klinisch nachweisbare Arthritis in SCID-Mäuse zu induzieren. Nach Reinokulation von cNE11H in Zecken und anschließender Reisolation aus verschiedenen Zeckenorganen, zeigten die meisten Reisolate eine Reaktion mit anti-OspC-Immunserum wie der Ausgangsklon cNE11H. Interessanterweise fand sich bei zwei Reisolaten aus dem Zeckenmitteldarm eine starke Expression des 22 kDa Proteins, welches durch das anti-OspC-Immunserum erkannt wurde. Darüberhinaus induzierten diese beiden Reisolate eine klinisch nachweisbare Arthritis in SCID-Mäusen. Zusammengefaßt zeigen unsere Resultate, daß die spirochätalen 22/23 kDa Proteine während der Zeckenpassage differentiell exprimiert werden. Darüberhinaus zeigen sie auch, daß spirochätale Proteine, die nach Kultivierungin vitro nicht mehr nachweisbar sind, dann reexprimiert werden können, wennB. burgdorferi der Mikroumgebung des Zeckenorganismus ausgesetzt wird. Wir postulieren, daß die Pathogenität vonB. burgdorferi in Mäusen durch umgebungsbedingte differentielle Expression der 22 und 23 kDa Proteine beeinflußt werden könnte.
    Notes: Summary ABorrelia garinii isolate (NE11H) was obtained from the hemolymph of infedIxodes ricinus. NE11H expressed four major proteins of 33 kDa, 32 kDa, 23 kDa and 22 kDa. Duringin vitro culture, NE11H successively lost the expression of the 22 kDa and 23 kDa proteins and the NE11H variant (NE11Hp15) was not recognized by an immune serum specific for the OspC protein (anti-OspC IS). However, when reintroduced into tick midguts, NE11Hp15 spirochetes present in the midgut again reacted with anti-OspC IS. A clone derived from the wild type line, cNE11H, lacked the 22 kDa but not the 23 kDa protein. The 23 kDa protein of cNE11H was recognized by anti-OspC IS. In addition, the two descendant lines (NE11Hp15 and cNE11H) lost their capacity to induce clinical arthritis in SCID mice. When cNE11H was reintroduced into ticks and reisolated from various tick organs, most reisolates presented the same reaction with anti-OspC IS as cNE11H. Interestingly, two reisolates obtained from the tick midgut reexpressed large amounts of the 22 kDa protein which was recognized by anti-OspC IS and these two reisolates induced clinical arthritis in SCID mice. The results confirm that proteins of 22/23 kDa are differentially expressed duringin vitro subcultures and in ticks, and show that proteins which are not detectable afterin vitro culture may be reexpressed after reexposure ofB. burgdorferi to its former environment in the tick. The data suggest that the pathogenicity ofB. burgdorferi for mice might be influenced by environmental factors via differential expression of 22/23 kDa proteins.
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  • 10
    ISSN: 1439-0973
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei Untersuchungen zur Impfstoffentwicklung gegen dieBorrelia burgdorferi-Infektion haben wir grundlegende Prinzipien der protektiven Immunantwort in einem murinen Modell erarbeitet. Wir fanden, daß das Oberflächenlipoprotein „outer surface protein A (lipOspA)“ in nativer und rekombinanter lipidierter Form monospezifische Immunseren induziert, die in passiven Transferexperimenten immuninkompetente (SCID) Mäuse gegen experimentelle und zeckenvermittelte Infektion und Erkrankung schützen. Diese Befunde zusammen mit ähnlichen Befunden anderer Arbeitsgruppen führten zur Entwicklung eines Impfstoffs auf der Basis des lipOspA. In klinischen Phase I/II Prüfungen erwies sich der rekombinante lipOspA-Impfstoff als verträglich und immunogen und fähig zur Induktion bakterizider anti-Borrelien-Antikörper. Zum gegenwärtigen Zeitpunkt werden klinische Phase III-Prüfungen zur Untersuchung der protektiven Effizienz durchgeführt. Ausgehend von der Stelle des Zeckenbisses kommt es bei derB. burgdorferi-Infektion zur Verbreitung der Spirochäten in entfernte Organe und zur Induktion einer chronischen Entzündung. Kürzlich durchgeführte Untersuchungen zeigen, daß die Borrelien möglicherweise wirtseigene humorale Enzymsysteme rekrutieren, die ihnen die Ausbreitung erleichtern. In diesem Zusammenhang fanden wir, daß das lipOspA als ein Oberflächenrezeptor für das wirtseigene proteolytische Enzym Plasmin(ogen) fungiert. Darüber hinaus konnten wir zeigen, daß Borrelien in der Lage sind, vaskuläre Endothelzellen und Leukozyten, wie Monozyten/Makrophagen, B Zellen und T Zellen, zu aktivieren. Die aktivierten Zellen exprimieren Funktionen und sezernieren Moleküle mit proinflammatorischer Wirkung. Ein Teil der stimulierenden Aktivitäten konnte auf das gereinigte lipOspA zurückgeführt werden. Unsere Studien weisen demnach darauf hin, daß lipOspA als Zielstruktur protektiver Antikörper nicht nur eine wichtige Rolle bei der Induktion einer protektiven Immunantwort, sondern auch bei den pathogenen Reaktionen im Rahmen derB. burgdorferi-Infektion spielt.
    Notes: Summary In the search for a suitable vaccine candidate for Lyme borreliosis the principles of protective immunity were studied in a murine model ofBorrelia burgdorferi infection. It was found that the spirochetal outer surface protein A (lipOspA) in its native and recombinant lipidated form induces monospecific immune sera, which in passive transfer experiments protect SCID mice against experimental and tick-borne infection and disease. These and similar findings of independent groups led to the development of a vaccine formulation containing lipOspA. When tested in clinical phase I/II safety trials the recombinant lipOspA vaccine was shown to be safe, immunogenic and able to elicit borreliacidal antibodies. At present, clinical phase III efficacy trials are being conducted.B. burgdorferi infection involves the dissemination of the spirochetes from the site of the tick bite, infection of distant organs, and induction of a chronic inflammatory process. Recent studies indicate that the spirochetes may utilize host-derived enzyme systems to increase their virulence/pathogenicity. It was found that lipOspA serves as a surface receptor for the host-derived proteolytic enzyme plasmin(ogen), the central component of the so-called plasminogen activator system. Moreover, it was found that spirochetes are able to activate endothelial cells and blood-derived leukocytes, such as monocytes/macrophages, B cells and T cells, to express functions and/or secrete molecules, which are known to promote inflammatory responses. Part of these activities were exerted by the isolated lipOspA. The studies indicate an important role of lipOspA, both for the induction of a protective immune response by the host, as well as for the pathogenic processes elicited duringB. burgdorferi infection.
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