Drug delivery in degenerative joint disease.
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Biomedical subjects
Publications and source records attributed to Nicole Gerwin.
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Osteoarthritis (OA) is a primarily non-inflammatory, degenerative joint disease characterized by progressive loss of articular cartilage, subchondral bone sclerosis, osteophyte formation, changes in the synovial membrane, and an increased volume of synovial fluid with reduced viscosity and hence changed lubrication properties. As OA is the most common type of arthritis and a leading cause of disability, there is a largely unmet medical need for disease-modifying and symptomatic treatment. Due to the localized nature of the disease, intraarticular (IA) drug injection is an attractive treatment approach for OA. The various glucocorticoid and hyaluronic acid (HA) formulations, which are currently available on the market for IA treatment, provide only short-term pain relief or/and often do not provide adequate pain relief. The available oral drugs for symptomatic treatment also have shortcomings, most notably side effects. Therefore, there is still a large unmet need for novel OA drugs, which provide effective long-term pain relief and/or have disease-modifying properties. To achieve long-term drug exposure, different established formulations such as suspensions and hydrogels, and also novel approaches such as lipid based formulations and nano- or microparticles are currently in development. The development of novel drugs in combination with new formulations for IA treatment of OA, represents a promising approach in this challenging area of research.
ICAM-2 has been implicated in leukocyte transmigration in vitro, but there is little in vivo evidence to support this. To address this, neutrophil migration was investigated in ICAM-2-deficient mice (KO) and in wild-type (WT) mice treated with an anti-ICAM-2 blocking monoclonal antibody (mAb) (3C4). In a peritonitis model, IL-1beta-induced accumulation of neutrophils was significantly reduced in mice treated with 3C4 (51% inhibition) and in KO mice (41% inhibition). In contrast, TNF-alpha- or thioglycolate-induced responses were not suppressed in KO mice. Analysis of IL-1beta-induced leukocyte responses in cremasteric venules of KO animals by intravital microscopy indicated a defect in transmigration (44% inhibition) but not rolling or adhesion. As found before, TNF-alpha-induced leukocyte transmigration was unaltered in the KO mice. WT mice treated with the anti-ICAM-2 mAb also exhibited a selective reduction in leukocyte transmigration in response to IL-1beta while an anti-ICAM-1 mAb inhibited both leukocyte adhesion and transmigration. Interestingly, mAb 3C4 significantly suppressed IL-1beta-induced neutrophil transmigration in PE-CAM-1 KO animals in the peritonitis model but not in the cremaster muscle. The findings provide direct evidence for the involvement of ICAM-2 in neutrophil transmigration in vivo, though this role appears to be stimulus specific. Furthermore, ICAM-2 appears capable of mediating PECAM-1-independent leukocyte transmigration.
Endothelial junctions maintain endothelial integrity and vascular homeostasis. They modulate cell trafficking into tissues, mediate cell-cell contact and regulate endothelial survival and apoptosis. Junctional adhesion molecules such as vascular endothelial (VE)-cadherin and CD31/platelet endothelial cell adhesion molecule (PECAM) mediate contact between adjacent endothelial cells and regulate leukocyte transmigration and angiogenesis. The leukocyte adhesion molecule intercellular adhesion molecule 2 (ICAM-2) is expressed at the endothelial junctions. In this study we demonstrate that endothelial ICAM-2 also mediates angiogenesis. Using ICAM-2-deficient mice and ICAM-2-deficient endothelial cells, we show that the lack of ICAM-2 expression results in impaired angiogenesis both in vitro and in vivo. We show that ICAM-2 supports homophilic interaction, and that this may be involved in tube formation. ICAM-2-deficient cells show defective in vitro migration, as well as increased apoptosis in response to serum deprivation, anti-Fas antibody, or staurosporine. ICAM-2 signaling in human umbilical vein endothelial cells (HUVECs) was found to activate the small guanosine triphosphatase (GTPase) Rac, which is required for endothelial tube formation and migration. These data indicate that ICAM-2 may regulate angiogenesis via several mechanisms including survival, cell migration, and Rac activation. Our findings identify a novel pathway regulating angiogenesis through ICAM-2 and a novel mechanism for Rac activation during angiogenesis.
The validation of a diffusion chamber comprising a donor and a receptor side separated by a cartilage membrane was undertaken according to the basic principles described by Peng et al. (1998). The study had three targets: first to evaluate the chamber as in vitro system by the examination of the diffusibility of compound through bovine cartilage samples; second the analysis of the affinity of compound (RS-130830) to cartilage; third to test the influence of two pre-incubation periods (one or three nights) of the cartilage samples. The validation of the chamber as in vitro system for the analysis of compound diffusibility and affinity to cartilage was performed using membrane slices of fresh bovine cartilage and a hydroxamic acid derivative (RS-130830) known as matrix metalloproteinase inhibitor (MMPI). The influence of the pre-incubation of cartilage was also examined. Compound concentrations in donor, receptor and membrane were determined by high performance liquid chromatography-mass spectrometry (HPLC-MS). Diffusion could be demonstrated after 6 h and finally 24 h incubation: the compound concentration in the receptor increased from 0 to 35 microM (mean) while it decreased in the donor from 200 to 144 microM (mean). We also found compound in the cartilage membrane (approximately 1.2 nmol (mean)). Pre-incubation of cartilage samples in culture buffer is suitable as a storage procedure, since the results on the donor side only were influenced significantly but not for the receptor and the cartilage affinity. Thus, the system could clearly reflect relevant properties of the tested compound with regard to its diffusibility and affinity to cartilage tissue.
OBJECTIVE: Osteoarthritic (OA) cartilage degeneration and cartilage destruction in rheumatoid arthritis depends significantly on enzymatic degradation of cartilage proteoglycan aggrecan. A member of the ADAMTS family of proteases, ADAMTS-1 was described to have "aggrecanase" activity. We investigated the quantitative expression and distribution of ADAMTS-1 in healthy and OA cartilage and in cultured articular chondrocytes with and without stimulation by interleukin 1beta (IL-1beta) and insulin-like growth factor-I (IGF-I). METHODS: Conventional and online polymerase chain reaction (PCR) technology was used to determine ADAMTS-1 mRNA expression levels of ADAMTS-1. Protein was localized using immunostaining with different polyclonal antibodies. RESULTS: Conventional and online semiquantitative PCR showed significant levels of ADAMTS-1 mRNA expression in normal and OA chondrocytes in vivo and in vitro. Only a slight increase was observed in OA cartilage. After stimulation with IL-1beta a downregulation of ADAMTS-1 was observed, whereas IGF did not appear to change mRNA expression levels in vitro. The in vivo mRNA expression results were confirmed by the presence of significant protein staining with antibodies for ADAMTS-1 in normal and OA chondrocytes as well as Western blotting analysis. Whereas a significantly stronger stain was seen in normal articular cartilage in the upper zones, in OA cartilage as well the middle zone showed enhanced staining. CONCLUSION: Our results confirm the expression and presence of ADAMTS-1 in articular cartilage. However, they also point out that ADAMTS-1 appears to be constitutively expressed by adult articular chondrocytes and overall is not strongly upregulated in OA. Thus our data suggest that ADAMTS-1 is the first matrix-degrading enzyme downregulated by the catabolic factor IL-1beta in vitro.
Endothelial intercellular adhesion molecule 1 (ICAM-1) and ICAM-2 are both involved in lymphocyte extravasation during immunosurveillance and inflammation. To define their exact role during T-cell extravasation, we used mouse T cells and ICAM-1-/-ICAM-2-/- brain endothelioma cells. ICAM-1-/-ICAM-2-/- brain endothelioma cells did not support transendothelial migration (TEM) of T cells in vitro. Re-expression of different ICAM-1 mutants in the ICAM-1-/-ICAM-2-/- endothelioma line bEndI1/2.1 or in the ICAM-1-/- endothelioma line bEndI1.1 demonstrated that the extracellular domain of ICAM-1 suffices to support T-cell adhesion while the presence of the cytoplasmic tail was strictly required for TEM. Surprisingly, tyrosine phosphorylation of endothelial ICAM-1 was not necessary for TEM of T cells or for Rho guanosine triphosphatase (RhoGTPase) activation. Furthermore, cytoplasmic deletion mutants of ICAM-1 were unable to mediate RhoGTPase activation. Thus, our data demonstrate that the cytoplasmic tail of endothelial ICAM-1-independently from tyrosine phosphorylation-is essential for supporting TEM of T lymphocytes, while Rho signaling is involved in endothelial cells.