The plasma level of soluble receptor for advanced glycation end products is decreased in patients with systemic lupus erythematosus.

In recent years, the role of high mobility group box-1 (HMGB1) protein and its receptors in autoimmune diseases has received increasing attention. It has been documented that HMGB1 is associated with disease activity in patients with systemic lupus erythematosus (SLE). This study was undertaken to determine the potential role of receptor for advanced glycation end products (RAGE), one receptor for HMGB1, in the pathogenesis of SLE. Plasma levels of soluble RAGE (sRAGE) from 105 patients with clinical diagnosis of SLE and 43 healthy controls were determined by ELISA. Associations between sRAGE levels and clinical, laboratory characteristics were assessed. The data showed that plasma levels of sRAGE in patients with SLE were significantly lower than those in healthy controls (HC) (P = 0.003). Plasma sRAGE in patients receiving short-period treatment showed an immediate decrease compared with the untreated patients (P = 0.023). In contrast, plasma sRAGE in patients receiving long-period treatment were significantly increased compared to those with short-period treatment (P = 0.000) and comparable with those in HC (P = 0.305). The significant decreased levels of sRAGE in patients with SLE suggest the potential association of RAGE signalling and SLE clinical pathology, whereas, long-period antilupus treatment may counteract the decreased sRAGE levels in patients with SLE.

Disparate distribution of activating and inhibitory killer cell immunoglobulin-like receptor genes in patients with systemic lupus erythematosus.

The genes of killer cell immunoglobulin-like receptors (KIRs), which are involved in the activation of T cells and natural killer cells, are highly variable. In recent years, the role of KIRs in autoimmune diseases has received increasing attention. The present study was undertaken to determine the association of the polymorphism of KIR genes with the susceptibility to systemic lupus erythematosus (SLE). The polymorphism of KIR genes of 93 patients with SLE together with 123 healthy donors as the control group was determined by polymerase chain reaction with sequence-specific primers. Twenty-seven novel gene combinations were found. Genotypic frequencies of KIR2DL2 (p < 0.001) and KIR2DS1 (p < 0.001) were much higher in patients with SLE than in control subjects. Individuals with two and more than two activating KIR genes were found more frequently in patients than in control subjects (80.7% versus 66.7%, p = 0.022). The results suggest that a genetic disturbance between activating and inhibitory KIR genes may be one of the key factors underlying the pathogenesis of SLE.

Three new diterpenoids from Coleus forskohlii Briq.

Three new diterpenoids, forskolin G(2), forskolin H(3), forskolin I(4), were isolated from the whole plant of the Coleus forskohlii Briq., and their structures were elucidated as 1alpha,6beta-diacetoxy-8,13-epoxylabd-14-en-11-one, 1alpha-hydroxy-6beta,7beta-diacetoxy-8,13-epoxylabd-14-en-11-one, and 1alpha,9alpha-dihydroxy-6beta,7alpha-diacetoxy-8,13-epoxylabd-14-en-11-one on the basis of spectral data.

Specific in vitro association between the hepatitis C viral genome and core protein.

Little is known about the molecular interactions required for hepatitis C virion assembly. The 5' noncoding region (5'NCR) of the RNA genome is highly conserved and has extensive secondary structure. The highly basic core protein is rich in arginine and lysine residues. We postulate that a specific interaction between these structures may be important for virion assembly. Using an RNA gel mobility shift assay, a specific interaction has been demonstrated between the RNA of the 5'NCR and recombinant core protein. Proteins from other regions of the virus do not interact with the viral RNA. The interaction is inhibited competitively by unlabelled sense polarity RNA, but antisense 5'NCR RNA and nonspecific RNAs compete only at much higher concentrations. These data suggest that there is a specific interaction between the 5'NCR of the hepatitis C virus (HCV) genome and HCV core protein. This interaction may be important for the specific encapsidation of the viral genome during HCV replication.

Effect of temperature on in vitro proliferative activity of human umbilical vein endothelial cells.

Human umbilical vein endothelial cells, skin fibroblasts, and retinal pigment epithelial cells are cultivated in medium supplemented with 15 to 20% serum in our laboratory. The effects of various incubation temperatures on the proliferation of these cells was examined. Our study shows that the mitogenic response of the endothelial cells to a change of temperature differed markedly from that of the fibroblasts and epithelial cells. Cultivation of human umbilical vein endothelial at 37 degrees C required seeding densities as high as 1-2 x 10(4) cells/cm2, and yet resulted in a low growth rate and premature senescence. However, under the same culture conditions, but at 33 degrees C, the proliferative capacity of these endothelial cells was potentiated. The results were striking; at 33 degrees C the cells grew actively and the life span was extended. The number of cumulative population doublings increased fourfold compared with that for the same cells cultivated at 37 degrees C. The inoculum size could be reduced, since at 33 degrees C the endothelial cells were able to replicate at seeding densities as low as 20 cells/cm2. The cells serially subcultured at 33 degrees C retained morphological features and specific immunological markers of endothelial cells.

Human retinal pigment epithelial cells from different donors continuously produce a vascular endothelial cell-stimulating factor into serum-free medium.

Mitogenic activities of human retinal pigment epithelial cell-conditioned medium (HRPE-CM) with different effects, such as inhibition, stimulation or no effect, on the proliferation of vascular endothelial cells (EC) in vitro have been reported. In this study, 14 HRPE cell lines were established from normal human eyes. Human umbilical vein endothelial cells (HUVEC) in the early passages were used as target cells to detect the mitogenic activity of HRPE-CM on the growth of vascular EC. Our results confirm that HRPE cells in culture continuously synthesize and secrete HUVEC growth substance(s) into a serum-free medium. The ability of HRPE cell lines to produce this mitogen seem unrelated either to in vivo donor factors or to in vitro cell life span. Using an enzyme-linked immunosorbance assay, we demonstrated that only HRPE cell extract, not HRPE-CM, can be recognized by basic fibroblast growth factor (bFGF)-specific antibody, though identical bioactivities on the growth of HUVEC were found in both preparations. The active component in HRPE-CM was heat- and trypsin-sensitive, and stable at extremes of pH (2.5 to 10.0). In addition, the bioactive molecule could not pass through a M(r) 30,000 cut-off membrane, suggesting that it is a fairly high molecular mass polypeptide. These observations suggest that the EC growth factor in HRPE-CM is distinct from fibroblast growth factors (FGFs).

[Mitotic effect of the pigment epithelium]. / Effet mitotique de l'épithélium pigmentaire.

The authors suggest the production by the cultured RPE cell of one or more angiogenic substances. This activity is highly increased when RPE are cultured in poor conditions, either due to a poor medium or after having been challenged by a high number of rod outer segments. The mitotic factor appears heat-labile and trypsine sensitive, but not dialysable which suggest their biochemical nature to be a protein.

The use of iodinated density gradient media for the isolation of rod outer segments.

Sucrose, nycodenz, metrizamide and a mixture of equal volumes of sucrose and metrizamide were used as density gradient media for the isolation of retinal rod outer segments. The high osmolarity of sucrose had a strongly negative effect on the nature of the rod outer segments, whereas they were much better preserved using iodinated density gradient media such as nycodenz and metrizamide for their isolation.