Biomedical subjects

O Serlupi-Crescenzi

Publications and source records attributed to O Serlupi-Crescenzi.

7 recordsLinked to original sources

PubMed2003

Inhibition of IL-6+IL-6 soluble receptor-stimulated aromatase activity by the IL-6 antagonist, Sant 7, in breast tissue-derived fibroblasts.

Interleukin 6 (IL-6) and its soluble receptor (IL-6sR) can markedly stimulate aromatase activity in cultured fibroblasts derived from normal or malignant breast tissues. IL-6 acts by binding to a low-affinity membrane-spanning receptor (IL-6R), which must associate with a high-affinity receptor (gp130) for signal transduction to occur. Sant 7 is a mutated form of IL-6 that can bind to the IL-6R, but inhibits its ability to interact with the gp130 signal transducing protein. In this study, we have used Sant 7 to examine its ability to inhibit IL-6+IL-6 soluble receptor (IL-6sR)-stimulated aromatase activity in breast tissue-derived fibroblasts. As previously observed, IL-6+IL-6sR markedly stimulated aromatase activity (7.7-20.8-fold) in fibroblasts derived from reduction mammoplasty tissue, tissue proximal to tumours and breast tumours. Sant 7 inhibited basal aromatase activity in some fibroblasts by 25-30% that had a high basal activity, but almost completely blocked the ability of IL-6+IL-6sR to stimulate aromatase activity. The IC(50) for the inhibition of IL-6+IL-6sR-stimulated aromatase activity by Sant 7 was 60 ng ml(-1). A comparison of the effects of prostaglandin E(2) (PGE(2)), which can also regulate aromatase activity, and IL-6+IL-6sR revealed a greater degree of aromatase stimulation by IL-6+IL-6sR. Sant 7, however, inhibited PGE(2)-stimulated aromatase activity by 70% suggesting that PGE(2) acts, in part, by stimulating IL-6 production. Much of the IL-6 and IL-6sR available to stimulate breast tumour aromatase activity may originate from infiltrating macrophages and lymphocytes. The ability to block aromatase stimulation by these factors may offer a novel therapeutic strategy for reducing oestrogen synthesis in breast tumours.

Aromatase↗

PubMed2000

An IL-6/IL-6 soluble receptor (IL-6R) hybrid protein (H-IL-6) induces EPO-independent erythroid differentiation in human CD34(+) cells.

H-IL-6 is a hybrid protein constructed to contain IL-6 and its soluble receptor linked by a flexible peptide chain. Here we show that H-IL-6 strongly enhances proliferation of human CD34(+)cells in serum-free liquid culture, and that the majority of the cells generated belong to the erythroid lineage, being positive for the marker Glycophorin A. Conversely, H-IL-6 does not increase the number of myeloid, CD13-positive cells. Comparable effects are observed on progenitors from cord blood and adult peripheral blood. Therefore, H-IL-6 triggers an erythroid-inducing signal in haematopoietic progenitor cells, independently from erythropoietin (EPO).

Antigens, CD34↗

PubMed1999

Interleukin 6 knock-out mice are resistant to antigen-induced experimental arthritis.

In order to assess the potential role of IL-6 in rheumatoid arthritis (RA), we have compared IL-6 deficient (IL-6 ko) mice and their wild-type (wt) counterpart for the capacity to develop methylated bovine serum albumin (mBSA)-induced arthritis. Our data show that IL-6 ko mice are not susceptible to antigen-induced arthritis (AIA). In fact, IL-6 ko mice treated by a standard protocol of immunization with mBSA did not develop joint swelling following intra-articular mBSA injection, nor revealed the characteristic joint lesions by histological examination. Conversely, wt mice treated according to the same protocol developed arthritis about 9 days after intra-articular injection, as detected by knee joint swelling and histological confirmation. We observed that the proliferative response of splenocytes to mBSA was impaired in ko mice following arthritis induction, as compared to the strong response observed in wt mice. Furthermore, anti-mBSA IgG levels were lower in ko mice as compared to wt mice. Finally, we show that sensitivity to AIA can be reconstituted in ko mice by subcutaneous injections of recombinant human IL-6 (rhIL-6). In addition, co-administration of IL-6 with mBSA by intra-articular injection into the joint was only partially effective in conferring sensitivity to AIA, suggesting the importance of a systemic effct for IL-6, but also that an additional role for this cytokine can be envisaged in the local inflammatory reaction during establishment of AIA.

Animals↗

PubMed1998

Highly conserved amino-acid sequence between murine STAT3 and a revised human STAT3 sequence.

Signal transducer and activator of transcription 3 (STAT3) is an important mediator of cytokine signaling, whose cDNA and protein sequences have been fully characterized. We sequenced the whole human STAT3 cDNA isolated from HepG2 cells. The new sequence determined contains 43 nucleotide changes overall, corresponding to six modifications at the amino-acid level. The revised amino-acid sequence of human STAT3 is now completely identical to the mouse sequence, except for a single amino-acid change at position 760. Thus STAT3 now results as one of the most evolutionarily conserved among known proteins. By using specific RT-PCR we could discriminate between the original sequence and the new variant. Amplification of regions within the src-homology domain 2 (SH2) of STAT3, from the RNAs of 11 different tissues or cells, revealed only the expression of the new SH2 variant. Besides, only this SH2 variant was amplified from human genomic DNA. We conclude that the new sequence we have determined in this study represents a revised sequence of hSTAT3 or, less likely, a new predominant allele.

Amino Acid Sequence↗

PubMed1996

A highly precise reporter gene bioassay for type I interferon.

We describe the setting up and validation of a reporter gene assay for type I IFN based on monkey Vero cells transfected with pMx-Luc, a plasmid carrying the luciferase gene under the control of the type I IFN inducible mouse Mx1 promoter. Vero cells were stably transfected with pMx-Luc and clone 3-143/5 was selected on the basis of luciferase inducibility by IFN-beta. A linear dose-response relationship was found between 1 and 16 IU/ml IFN-beta. The assay was shown to be specific for IFN-alpha and -beta as no effect by a number of other cytokines including IFN-gamma could be detected. In order to render the IFN-beta reporter gene assay protocol more suitable for routine assays, a 3 x 3 balanced parallel line assay design was applied using a 96-well luminometer for luminescence measurement. The assay was shown to be precise with a coefficient of variation of less than 9%. This assay is characterized by high precision coupled to high efficiency, as reflected by a very short assay duration (1 day), when compared to the classical cytopathic effect assays for IFNs and the previously published IFN reporter gene assay based on growth hormone measurement (Lleonart, R., Näf, D., Browning, H. and Weissmann, C. (1990) A novel, quantitative bioassay for type 1 interferon using a recombinant indicator cell line. Biotechnology 8, 1263-1267).

Animals↗

PubMed1983

Developmental defects resulting from arginine auxotrophy in Aspergillus nidulans.

A mutant of Aspergillus nidulans, isolated for inability to form asexual spores (conidia) on complete medium, was found to regain the ability to conidiate if the medium was supplemented with arginine. On minimal medium the mutant required arginine for growth but at a much lower concentration than that required for conidiation. This mutant, designated argB12, thus defines a phase-critical gene, i.e. a gene whose function is in greater demand for development than for growth. In addition to its aconidial phenotype, the mutant also exhibited (depending on the medium) aberrant sexual development and a low efficiency of conidial germination. In crosses, each of these developmental phenotypes segregated with arginine auxotrophy. Genetic and biochemical analyses showed the argB12 mutation to be an allele of the previously described argB locus, mutants of which lack ornithine transcarbamylase. Arginine-requiring mutants at at least two other loci were also found to be defective in asexual sporulation, but the germination defect appears to be specific to argB mutants.

Arginine↗

PubMedDate not supplied

Effect of natural beta-interferon on estrogen receptor mRNA of breast cancer cells.

We have demonstrated that natural beta-interferon (beta-IFN) enhances estrogen receptor (ER) mRNA of a human breast cancer cell line, CG-5. Cells were sensitive to the effect of beta-IFN at concentrations ranging from 10 to 100 IU/ml. The increase of ER mRNA was seen after 48 hr of treatment in at least three separate experiments. Our results are in agreement with the previously observed enhancement of receptor protein. In addition, they suggest that the IFN-induced promotion of the antiproliferative activity of drugs which act via ER may be due, in part, to increased receptor synthesis.

Blotting, Northern↗