Dataset Information

Differential expression of prostaglandin-H synthase isoenzymes in normal and activated keratinocytes in vivo and in vitro.

ABSTRACT: Normal mouse epidermis constitutively expresses prostaglandin-H synthase 1 (PGHS-1) but no PGHS-2. Acute inflammation and epidermal hyperplasia, (hyperplastic transformation), as evoked in adult mouse skin in vivo by wounding or by the phorbol ester phorbol 12-myristate 13-acetate (PMA), resulted in a transient induction of PGHS-2 expression while PGHS-1 remained unchanged. Under conditions of a stationary epidermal hyperplasia, as in neonatal mouse epidermis, PGHS-1, but not PGHS-2, expression was observed. Induction of 'balanced hyperproliferation' by 4-O-methyl-phorbol 12-myristate 13-acetate (4-O-methyl-PMA) did not lead to PGHS-2 expression. When keratinocytes were isolated from neonatal mouse skin and separated by Percoll density-gradient centrifugation according to their stage of differentiation, PGHS-1 mRNA expression and protein were found to be highest in the differentiated cells compared with those from the proliferative compartment. A similar distribution of PGHS-1 mRNA was found in keratinocytes from adult mice, whereas PGHS-1 protein was equally distributed in all cell types. Contrary to the situation in intact epidermis, PGHS-2 mRNA but no protein was detected in all cell fractions. Established keratinocyte lines constitutively expressed both isoenzymes at different ratios. In the mouse line MSCP5 an almost exclusive expression of PGHS-2 was found, which was further enhanced by PMA treatment. These data indicate that the expression of PGHS-2 in mouse epidermis is specifically related to the emergency reaction of hyperplastic transformation.

SUBMITTER: Scholz K

PROVIDER: S-EPMC1135829 | biostudies-other | 1995 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:Two different macrophage populations contribute to CNS neuroinflammation: CNS-resident microglia and CNS-infiltrating peripheral macrophages. Markers distinguishing these two populations in tissue sections have not been identified. Therefore, we compared gene expression between LPS (lipopolysaccharide)/interferon (IFN)gamma-treated microglia from neonatal mixed glial cultures and similarly treated peritoneal macrophages. Fifteen molecules were identified by quantative PCR (qPCR) as being enriched from 2-fold to 250-fold in cultured neonatal microglia when compared with peritoneal macrophages. Only three of these molecules (C1qA, Trem2, and CXCL14) were found by qPCR to be also enriched in adult microglia isolated from LPS/IFNgamma-injected CNS when compared with infiltrating peripheral macrophages from the same CNS. The discrepancy between the in vitro and in vivo qPCR data sets was primarily because of induced expression of the 'microglial' molecules (such as the tolerance associated transcript, Tmem176b) in CNS-infiltrating macrophages. Bioinformatic analysis of the approximately 19000 mRNAs detected by TOGA gene profiling confirmed that LPS/IFNgamma-activated microglia isolated from adult CNS displayed greater similarity in total gene expression to CNS-infiltrating macrophages than to microglia isolated from unmanipulated healthy adult CNS. In situ hybridization analysis revealed that nearly all microglia expressed high levels of C1qA, while subsets of microglia expressed Trem2 and CXCL14. Expression of C1qA and Trem2 was limited to microglia, while large numbers of GABA+ neurons expressed CXCL14. These data suggest that (i) CNS-resident microglia are heterogeneous and thus a universal microglia-specific marker may not exist; (ii) the CNS micro-environment plays significant roles in determining the phenotypes of both CNS-resident microglia and CNS-infiltrating macrophages; (iii) the CNS microenvironment may contribute to immune privilege by inducing macrophage expression of anti-inflammatory molecules.

Project description:RationaleThe development of inhibitors of microsomal prostaglandin (PG)E2 synthase-1 (mPGES-1) was driven by the promise of attaining antiinflammatory agents with a safe cardiovascular profile because of the possible diversion of the accumulated substrate, PGH2, towards prostacyclin (PGI2).ObjectivesWe studied the effect of the human mPGES-1 inhibitor, AF3485 (a benzamide derivative) on prostanoid biosynthesis in human whole blood in vitro. To characterize possible off-target effects of the compound, we evaluated: i)the impact of its administration on the systemic biosynthesis of prostanoids in a model of complete Freund's adjuvant (CFA)-induced monoarthritis in rats; ii) the effects on cyclooxygenase (COX)-2 expression and the biosynthesis of prostanoids in human monocytes and human umbilical vein endothelial cells (HUVECs) in vitro.MethodsProstanoids were assessed in different cellular models by immunoassays. The effect of the administration of AF3485 (30 and 100 mg/kg,i.p.) or celecoxib (20mg/kg, i.p.), for 3 days, on the urinary levels of enzymatic metabolites of prostanoids, PGE-M, PGI-M, and TX-M were assessed by LC-MS.ResultsIn LPS-stimulated whole blood, AF3485 inhibited PGE2 biosynthesis, in a concentration-dependent fashion. At 100μM, PGE2 levels were reduced by 66.06 ± 3.30%, associated with a lower extent of TXB2 inhibition (40.56 ± 5.77%). AF3485 administration to CFA-treated rats significantly reduced PGE-M (P < 0.01) and TX-M (P < 0.05) similar to the selective COX-2 inhibitor, celecoxib. In contrast, AF3485 induced a significant (P < 0.05) increase of urinary PGI-M while it was reduced by celecoxib. In LPS-stimulated human monocytes, AF3485 inhibited PGE2 biosynthesis with an IC50 value of 3.03 µM (95% CI:0.5-8.75). At 1μM, AF3485 enhanced TXB2 while at higher concentrations, the drug caused a concentration-dependent inhibition of TXB2. At 100 μM, maximal inhibition of the two prostanoids was associated with the downregulation of COX-2 protein by 86%. These effects did not involve AMPK pathway activation, IkB stabilization, or PPARγ activation. In HUVEC, AF3485 at 100 μM caused a significant (P < 0.05) induction of COX-2 protein associated with enhanced PGI2 production. These effects were reversed by the PPARγ antagonist GW9662.ConclusionsThe inhibitor of human mPGES-1 AF3485 is a novel antiinflammatory compound which can also modulate COX-2 induction by inflammatory stimuli. The compound also induces endothelial COX-2-dependent PGI2 production via PPARγ activation, both in vitro and in vivo, which might translate into a protective effect for the cardiovascular system.

Dataset Information

Differential expression of prostaglandin-H synthase isoenzymes in normal and activated keratinocytes in vivo and in vitro.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets