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Biomedical subjects

Peter Finan

Publications and source records attributed to Peter Finan.

6 recordsLinked to original sources
PubMed2003

Therapeutic potential of phosphoinositide 3-kinase inhibitors.

At least one Holy Grail for many academic researchers and pharmaceutical research divisions alike has been to identify therapeutically useful selective PI3K inhibitors. There are several different but closely related PI3Ks which are thought to have distinct biological roles. Until now, however, researchers have been frustrated by poor selectivity of the available pharmacological inhibitors, which are unable to distinguish the different isoforms of PI3K adequately. Fortunately, recently published work gives cause for optimism; there are now several patent specifications published that describe new PI3K inhibitors, including some that are more selective for the delta isoform of PI3K. Given the involvement of PI3Ks in a plethora of biological settings, such isoform-selective inhibitors may have immense potential use for the treatment of patients with inflammatory and autoimmune disorders as well as cancer and cardiovascular diseases.

Autoimmune Diseases↗
PubMed2003

Isoform-specific phosphoinositide 3-kinase inhibitors as therapeutic agents.

The phosphoinositide 3-kinase (PI3K) family of enzymes consists of several closely related isoforms that are thought to have distinct biological roles. Until now, researchers have been frustrated by poor selectivity of the available pharmacological inhibitors, which are unable to distinguish adequately the activities of different PI3K isoforms. Recently published patent specifications describe new PI3K inhibitors, including several that are selective for the PI3Kdelta isoform. There is now cautious optimism that isoform-selective PI3K inhibitors will provide new avenues for therapeutic applications in a range of diseases.

Animals↗
PubMed2003

Expression and characterization of a 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid receptor highly expressed on human eosinophils and neutrophils.

Using a bioinformatics approach, we have isolated a novel G-protein-coupled receptor (GPCR), R527, and have demonstrated that this receptor shows no significant homology to previously deorphanized GPCRs. Quantitative reverse transcription-polymerase chain reaction analysis of the expression of GPCR R527 indicated a very high level of mRNA expression in eosinophils, with high expression also detected in neutrophils and lung macrophages. Stable cell lines were generated expressing this receptor together with the G-protein alpha-subunit G alpha(16). These cells were used to screen an agonist collection in a calcium mobilization assay and 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-oxo-ETE) was identified as a putative ligand. 5(S)-hydroxyperoxy-6E,8Z,11Z,14Z-eicosatetraenoic acid was also shown to activate the receptor, whereas the leukotrienes LTB(4), LTC(4), LTD(4), and LTE(4) failed to elicit a response. In cAMP assays, pertussis toxin reversed the inhibitory effects of 5-oxo-ETE on cAMP production, indicating that the receptor is G alpha(i)-coupled. The GPCR R527 shows pharmacological properties similar to those of the previously described 5-oxo-ETE receptor expressed on eosinophils, neutrophils, and monocytes. These cell types show chemotactic responses to 5-oxo-ETE, and this eicosanoid has been proposed to play a key role in the inflammatory response. The molecular identification of a receptor binding 5-oxo-ETE will expand our understanding of the physiological role of this mediator and may provide new therapeutic opportunities.

Amino Acid Sequence↗
PubMed2002

Phosphoinositide 3-kinase gamma is an essential amplifier of mast cell function.

Mast cells are key regulators in allergy and inflammation, and release histamine upon clustering of their IgE receptors. Here we demonstrate that murine mast cell responses are exacerbated in vitro and in vivo by autocrine signals through G protein-coupled receptors (GPCRs) and require functional phosphoinositide 3-kinase gamma (PI3Kgamma). Adenosine, acting through the A(3) adenosine receptor (A(3)AR) as well as other agonists of G(alphai)-coupled GPCRs, transiently increased PtdIns(3,4,5)P(3) exclusively via PI3Kgamma. PI3Kgamma-derived PtdIns(3,4,5)P(3) was instrumental for initiating a sustained influx of external Ca(2+) and degranulation. Mice lacking PI3Kgamma did not form edema after intradermal injection of adenosine and when challenged by passive systemic anaphylaxis. PI3Kgamma thus relays inflammatory signals through various G(i)-coupled receptors and is central to mast cell function.

Animals↗
PubMed2002

IL-10 expression profiling in human monocytes.

Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine with numerous immunomodulatory effects, including the inhibition of proinflammatory cytokine production. The mechanisms by which IL-10 exerts these effects still remain largely unknown. As there is evidence that suggests IL-10-mediated cytokine suppression requires the induction of an intermediate gene, we have used gene-chip technology to identify IL-10-inducible genes in human monocytes. We have been able to identify a total of 19 genes that are up-regulated in response to IL-10. Three of these genes had been identified previously: IL-1ra, suppressors of cytokine signaling-3, and CD163; however, the other 16 represent newly identified IL-10-responsive genes. Further analysis of the regulation of eight of these genes showed a remarkable specificity to regulation by lipopolysaccharides (LPS) and IL-10, but not by other anti-inflammatory mediators such as IL-4 and transforming growth factor-beta, suggesting that two diverse stimuli such as IL-10 and LPS may engage common signaling mechanisms.

Anti-Inflammatory Agents↗