Leukocyte recruitment in response to inflammatory signals is governed, in part, by binding to Thy-1 (CD90) on activated endothelial cells (EC). In this study, we characterized the adhesion G-protein coupled receptor CD97, present on peripheral myeloid cells, as a novel interacting partner for Thy-1. CD97 was upregulated on polymorphonuclear cells (PMNC) of patients with psoriasis.
View Article and Find Full Text PDFWe recently demonstrated that dexamethasone, a strongly atrophogenic glucocorticoid (GC), downregulated hyaluronan (HA) production in human keratinocytes and fibroblasts in vitro and after topical application to human skin in vivo via suppression of hyaluronan synthase 2 (HAS2). To test whether HAS2 activity might discriminate the atrophogenic potential of other substances applied topically to skin, we compared the HA metabolism in cultured human fibroblasts following in vitro treatment with GCs and the non-atrophogenic calcineurin inhibitor tacrolimus. GCs suppressed HAS2 mRNA expression and decreased HA as shown by qRT-PCR or ELISA.
View Article and Find Full Text PDFFollowing antigen contact, maturation and migration of DCs into lymphatic tissues are crucial to the developing immune response or maintenance of tolerance. Lysophosphatidylcholine (LysoPC) is generated during apoptosis of cells and acts as a "find-and-eat-me" signal thought to prevent autoimmunity. Moreover, LysoPC can activate PKCδ and initiates a signaling cascade that leads to phosphorylation and inactivation of syndecan-4 (SDC4), a heparansulfate proteoglycan integrin co-receptor.
View Article and Find Full Text PDFBackground And Purpose: Compression therapy is an essential part in the treatment of patients with venous leg ulcers. However, not all patients follow this recommendation. The authors tried to analyze how many patients performed compression therapy at the time of data collection and the reasons for insufficient or missing compression therapy.
View Article and Find Full Text PDFWe present an 80-year-old patient who presented a defect with exposed tendons on the dorsum of the hand after micrographic controlled tumour excision. The defect was closed using a combination of artificial collagen-elastin matrix (Matriderm) covered by an autologous split-skin graft in a 1-step approach resulting in rapid healing and good functional and cosmetic results.
View Article and Find Full Text PDFSkin atrophy is part of the normal ageing process, but is accelerated by topical glucocorticoid (GC) treatments that are widely used in dermatology. Hyaluronan (HA) is one of the most abundant components of the cutaneous extracellular matrix and is involved in tissue homeostasis, hydration, and repair processes, but little is known about the effects of GCs on HA synthesis and stability. Here we examined the regulation of HA metabolism in human skin during GC therapy.
View Article and Find Full Text PDFBackground: Rosai-Dorfman disease is a non-Langerhans cell histiocytosis that recently has been treated successfully with imatinib mesylate in a patient with a systemic variant of the disease.
Observations: We describe a 69-year-old man with cutaneous Rosai-Dorfman disease manifesting as progressive, deeply infiltrated skin lesions. Histopathologic examination of the lesions demonstrated dense dermal infiltrate positive for CD68, stabilin-1, and S-100, but not for CD1a.
Background: Patients with chronic leg ulcers are handicapped in daily life, both by physical complaints and social problems. The aim of our study was not only to assess a possible impairment of quality of life (QOL) of leg ulcer patients but also to evaluate if there is a real improvement of QOL after healing of the ulcer. Patients with chronic venous insufficiency served as the control group.
View Article and Find Full Text PDFCD44 proteins are cell surface receptors for hyaluronic acid (HA), a component of the extracellular matrix that has multiple effects on cell behavior. CD44 can be shed from the cell surface by proteolytic cleavage. The resulting soluble form can interfere with the interaction between HA and membrane-bound CD44.
View Article and Find Full Text PDFIn times of increasing economical pressure on the health care systems, it is important to optimise the outpatient treatment of chronic wounds. Another aim of wound healing research is to discover agents to accelerate healing. Wound healing trajectories or healing velocities can provide information to demonstrate the endpoints for wound healing.
View Article and Find Full Text PDFSmall fragments of the extracellular matrix component hyaluronic acid (sHA) are typically produced at sites of inflammation and tissue injury and have been shown to be associated with tumor invasiveness and metastasis. Here we report that exposure of human melanoma cells to sHA leads to nuclear factor kB (NFk-B) activation followed by enhanced expression of matrix metalloprotease (MMP) 2 and interleukin (IL)-8, factors that can contribute to melanoma progression. At the receptor level, we found that Toll-like receptor (TLR) 4 is involved in this signalling pathway, similar to the case in dendritic and endothelial cells.
View Article and Find Full Text PDFAllergy either results from a pathological excessive immune reaction, or from the defective induction of tolerance to otherwise harmless antigens. Allergic reactions are mounted by mechanisms of innate and adaptive immunity. The development of an allergic response can be divided in sensitization and elicitation phases.
View Article and Find Full Text PDFUltraviolet radiation (UVR) is known to be involved in the initiation and progression of malignant melanoma. Many studies have focused on the initiation of melanoma, but less is known about the effect of UVR on established tumor cells. Here, we show that after ultraviolet-B (UVB) irradiation, melanoma cells (MM) are able to secrete autocrine factors that enhance their motility.
View Article and Find Full Text PDFDendritic cells (DCs) need to mobilize within the extracellular matrix (ECM) during their maturation and concomitant migration from peripheral sites to lymphoid organs. Syndecans are cell surface proteoglycans that mediate the interaction of DCs with the ECM. Here we investigated the influence of syndecans on dendritic cell motility and morphology.
View Article and Find Full Text PDFTo trigger an effective T cell-mediated immune response in the skin, cutaneous dendritic cells (DC) migrate into locally draining lymph nodes, where they present Ag to naive T cells. Little is known about the interaction of DC with the various cellular microenvironments they encounter during their migration from the skin to lymphoid tissues. In this study, we show that human DC generated from peripheral blood monocytes specifically interact with human dermal fibroblasts via the interaction of beta(2) integrins on DC with Thy-1 (CD90) and ICAM-1 on fibroblasts.
View Article and Find Full Text PDFHyaluronan (HA), a major component of the cutaneous extracellular-matrix, is involved in tissue repair. Human skin is exposed to and damaged by UVB-irradiation. Here, we investigate the regulation of HA metabolism in human skin during acute UVB-induced inflammation.
View Article and Find Full Text PDFIn skin, an evolving inflammatory or immune response is triggered by early release of a cytokine cascade into the extracellular space. Investigation of extracellular cytokine secretion in situ has been limited by low cut-off filtering membranes and sample volume size and the inability to monitor changes in cytokine protein levels in real-time in situ. Here, we combine for the first time the methods of intradermal microdialysis and antibody protein arraying to profile the early cascade of multiple cytokines in a complex inflammatory response exemplified by ultraviolet B (UVB)-induced inflammation.
View Article and Find Full Text PDFThe dentate gyrus of rodents is characterized by a highly laminar organization: above a compact granule cell layer, commissural/associational (C/A) fibers terminate on proximal granule cell dendrites and entorhinal fibers terminate on distal granule cell dendrites in a nonoverlapping manner. To gain insights into mechanisms that underlie the formation of this laminar structure, we studied mice deficient for BETA2/NeuroD, a basic helix-loop-helix transcription factor essential for granule cell differentiation. Anterograde tracing was used to label C/A and entorhinal fibers and combined with confocal double immunofluorescence for calbindin, calretinin, parvalbumin, and reelin to visualize putative target cells.
View Article and Find Full Text PDFReactive axonal sprouting occurs in the fascia dentata after entorhinal cortex lesion. This sprouting process has been described extensively in the rat, and plasticity-associated molecules have been identified that might be involved in its regulation. To demonstrate causal relationships between these candidate molecules and the axonal reorganization process, it is reasonable to analyze knockout and transgenic animals after entorhinal cortex lesion, and because gene knockouts are primarily generated in mice, it is necessary to characterize the sprouting response after entorhinal cortex lesion in this species.
View Article and Find Full Text PDFSynaptopodin is the first member of a novel class of proline-rich actin-associated proteins. In brain, it is present in the neck of a subset of mature telencephalic spines and is associated closely with the spine apparatus, a Ca(2+) storing organelle within the spine compartment. The characteristic region- and lamina-specific distribution of synaptopodin in rat brain suggested that the distribution pattern of synaptopodin depends on the cytoarchitectonic arrangement of spine-bearing neurons.
View Article and Find Full Text PDFWe have studied the organization and cellular differentiation of dentate granule cells and their axons, the mossy fibers, in reeler mutant mice lacking reelin and in mutants lacking the reelin receptors very low density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2). We show that granule cells in reeler mice do not form a densely packed granular layer, but are loosely distributed throughout the hilar region. Immunolabeling for calbindin and calretinin revealed that the sharp border between dentate granule cells and hilar mossy cells is completely lost in reeler mice.
View Article and Find Full Text PDFThe fascia dentata of the hippocampal formation is characterized by the nonoverlapping and lamina-specific termination of afferent fibers: entorhinal fibers terminate in the outer molecular layer and commissural/associational fibers terminate in the inner molecular layer. It has been proposed that this fiber lamination depends on the presence of the correct postsynaptic partner at the time of fiber ingrowth during development. Pioneer neurons that guide afferent fibers to their correct layers as well as signals located on granule cells have both been implicated.
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