Jørgen K. Larsen

uPARAP/Endo180 is essential for cellular uptake of collagen and promotes fibroblast collagen adhesion

The uptake and lysosomal degradation of collagen by fibroblasts constitute a major pathway in the turnover of connective tissue. However, the molecular mechanisms governing this pathway are poorly understood. Here, we show that the urokinase plasminogen activator receptor–associated protein (uPARAP)/Endo180, a novel mesenchymally expressed member of the macrophage mannose receptor family of endocytic receptors, is a key player in this process. Fibroblasts from mice with a targeted deletion in the uPARAP/Endo180 gene displayed a near to complete abrogation of collagen endocytosis. Furthermore, these cells had diminished initial adhesion to a range of different collagens, as well as impaired migration on fibrillar collagen. These studies identify a central function of uPARAP/Endo180 in cellular collagen interactions.

Molecular Pharmacological Phenotyping of EBI2 AN ORPHAN SEVEN-TRANSMEMBRANE RECEPTOR WITH CONSTITUTIVE ACTIVITY

Epstein-Barr virus (EBV)-induced receptor 2 (EBI2) is an orphan seven-transmembrane (7TM) receptor originally identified as the most up-regulated gene (>200-fold) in EBV-infected cells. Here we show that EBI2 signals with constitutive activity through Gαi as determined by a receptor-mediated inhibition of forskolin-induced cAMP production and an induction of the serum response element-driven transcriptional activity in a pertussis toxin-sensitive manner. Gαs and Gαq were not activated constitutively as determined by the lack of cAMP production, the lack of inositol phosphate turnover, and the lack of activities of the transcription factors: cAMP response element-binding protein and nuclear factor-κB. Immunohistochemistry and confocal microscopy of FLAG- and green fluorescent protein-tagged EBI2 revealed cell-surface expression. A putative N-terminal truncated version of EBI2, Δ4-EBI2, showed similar expression and signaling through Gαi as full-length EBI2. By using a 32P-labeled EBI2 probe we found a very high expression in lymphoid tissue (spleen and lymph node) and peripheral blood mononuclear cells and a high expression in lung tissue. Real-time PCR of EBV-infected cells showed high expression of EBI2 during latent and lytic infection, in contrast to the EBV-encoded 7TM receptor BILF1, which was induced during lytic infection. EBI2 clustered with the orphan GPR18 by alignment analysis as well as by close proximity in the chromosomal region 13q32.3. Based on the constitutive signaling and cellular expression pattern of EBI2, it is suggested that it may function in conjunction with BILF1 in the reprogramming of the cell during EBV infection.

DNA analysis by flow cytometry in cutaneous T‐cell lymphomas

DNA histograms of skin and blood specimens from 64 patients with known or suspected cutaneous T‐cell lymphoma (CTCL) have been examined and compared with normal blood mononuclear cells and skin biopsy samples from 50 patients with various benign cutaneous conditions (i.e. patch test infiltrates, eczema, psoriasis, lichen planus, atopic dermatitis) in an attempt to establish whether DNA measurements by flow cytorntry may improve the early recognition of CTCL. The results indicate that right‐skewed G0/G1 peaks are seen frequently in both benign disorders and known and suspected CTCL. Such peaks may reflect increased stainability of DNA due to chromatin dispersion during cell activation and/or cell proliferation and do not constitute reliable evidence of malignancy. In contrast, discrete aneuploid DNA peaks are confined to malignant lesions, but are seen almost exclusively in the advanced stages in which the diagnosis can be establignohed easily based on routine histological criteria. These data indicate that DNA measurements by flow cytometry is of only limited help in the early recognition of CTCL and support the view that the lymphoid infiltrate in early CTCL may be reactive (rather than neoplastic) or alternatively may contain only minor populations of abnormal (malignant) cells which cannot be detected by currently available DNA measurement techniques.

Adaptive changes in the acute haemodynamic effects of cilazapril during chronic treatment Comparison with long-term clinical effect

Objective: To study the adaptive changes in the acute haemodynamic response to ACE inhibition during chronic treatment in CHF.Methods:The acute and chronic effects of oral cilazapril (CLZ) treatment, an ACE-inhibitor with prolonged duration on haemodynamic measures (PCWP, PAP, RAP, CI and SVR) and clinical parameters (Quality-of-Life and NYHA class) were investigated in a double-blind, randomised, placebo-controlled trial in CHF. One hundred and thirty five patients (112 completing) in NYHA Classes II-III, on digitalis and diuretic treatment, were randomised after 2 weeks of placebo run-in, to receive either placeabo or CLZ 0.5 mg, 1.0 mg or 2.5 mg daily for 12 weeks, followed by 2 week placebo wash-out. Haeamodynamic studies, including exercise tests before and 3 h after medication, were performed on the first and last days of treatment. Measurements were performed at rest and at the maximum exercise level.Results:In ACEI-naive patients oral CLZ 0.5 and 1 mg/d caused a dose dependent decrease in PCWP and diastolic PAP, and a significant reduction of SVR mg. A slight increase in CI was observed in all groups. The maximum effect was observed 3–5 h post dose. After 12 weeks of oral treatment, the acute response was similar but was attenuated relative to the first dose. Exercise tolerance improved in a dose dependent manner. The NYHA classification remained unchanged or improved in the majority of patients. Entry into the 2.5 mg group had to be terminated at an early stage due to severe adverse events observed after the first dose.Conclusion:During chronic treatment, the haemodynamic response to oral cilazapril was attenuated, indicating that continued clinical improvement in patients with CHF on CLZ is independent of to its acute haemodynamic effects.

In cutaneous T-cell lymphoma, class II MHC molecules on CD1+ antigen-presenting cells are upregulated in involved compared with uninvolved epidermis

CD1+ antigen‐presenting cells in involved epidermis of patients with cutaneous T‐cell lymphoma exhibit an enhanced functional capacity to activate autologous CD4+ T cells compared with CD1+ antigen‐presenting cells from uninvolved and normal epidermis. Class II major histocompatibility complex molecules are involved in antigen presentation, and their expression on CD1+ Langerhans cells is known to vary. The expression of all three class II (HLA‐DR, ‐DQ, ‐DP) molecules was therefore determined on CD1+ epidermal cells from both involved and uninvolved epidermis, using flow cytometry. The involved CD1+ epidermal cells exhibited a 1.5–1.6‐fold, statistically significant increase in fluorescence intensity after staining of the class II molecules (HLA‐DR, ‐DQ, ‐DP) compared with CD1+ epidermal cells from uninvolved epidermis. The autologous CD4+ T‐cell activation was almost completely blocked by anti‐HLA‐DR, and partly by anti‐HLA‐DQ and anti‐HLA‐DP.

Abnormal growth of ovarian antral follicles in breast cancer patients

Ovarian antral follicles from patients with breast cancer were compared with follicles from healthy women. Steroid levels in the follicular fluid and the health status of the follicles were evaluated. Follicles were judged to be healthy or atretic by flow cytometric determinations of the deoxyribonucleic acid content of aspirated granulosa cell nuclei. Fifteen of the 25 follicles (60%) from the cancer patients contained unmeasurable or abnormally low steriod levels (i.e., less than 100 ng/ml) which were significantly (P less than 0.001) lower than in follicles of the same health status from healthy women (500 to 1000 ng/ml). It is speculated whether substances other than the usual follicular steriods are produced by the cancer patients, which stimulate mitotic activity of the granulosa cells.