OBJECTIVETo determine the expression of E-prostanoid1 (EP(1)) and F-prostanoid (FP) receptor mRNAs in iris-ciliary bodies of the human eye using in situ hybridization.

METHODSEP(1) and FP receptor mRNAs were detected by riboprobes labeled with digoxigenin on paraffin sections of the iris-ciliary body tissue of the human eye using in situ hybridization.

RESULTSEP(1) and FP receptor mRNAs were highly expressed in blood vessels, muscles and the endothelia of the iris. EP(1) receptor hybridization signals were present in all muscle fibers of the ciliary body. Hybridization signal corresponding to FP receptor mRNA transcript was predominantly expressed in the circular muscle and in the collagenous connective tissues of the ciliary body. FP receptor mRNA was not detected in radial and longitudinal muscles.

CONCLUSIONSEP(1) and FP receptor mRNAs in human ocular tissues appear to be widely localized in the functional sites of the respective receptor agonists. Selective localization of EP(1) and FP receptor mRNAs in the circular muscles and collagenous connective tissues of the ciliary body suggests that EP(1) and FP receptors play an important role in enhancing uveoscleral outflow of aqueous humor.

Ciliary Body ; metabolism ; Humans ; In Situ Hybridization ; Iris ; metabolism ; RNA, Messenger ; analysis ; Receptors, Prostaglandin ; genetics ; Receptors, Prostaglandin E ; genetics ; Receptors, Prostaglandin E, EP1 Subtype

The worldwide prevalence of obesity is steadily increasing, nearly doubling between 1980 and 2008. Obesity is often associated with insulin resistance, a major risk factor for type 2 diabetes mellitus (T2DM): a costly chronic disease and serious public health problem. The underlying cause of T2DM is a failure of the beta cells of the pancreas to continue to produce enough insulin to counteract insulin resistance. Most current T2DM therapeutics do not prevent continued loss of insulin secretion capacity, and those that do have the potential to preserve beta cell mass and function are not effective in all patients. Therefore, developing new methods for preventing and treating obesity and T2DM is very timely and of great significance. There is now considerable literature demonstrating a link between inhibitory guanine nucleotide-binding protein (G protein) and G protein-coupled receptor (GPCR) signaling in insulin-responsive tissues and the pathogenesis of obesity and T2DM. These studies are suggesting new and emerging therapeutic targets for these conditions. In this review, we will discuss inhibitory G proteins and GPCRs that have primary actions in the beta cell and other peripheral sites as therapeutic targets for obesity and T2DM, improving satiety, insulin resistance and/or beta cell biology.
Animals ; Diabetes Mellitus, Type 2/drug therapy/*metabolism ; GTP-Binding Protein alpha Subunits/genetics/*metabolism ; Humans ; Insulin-Secreting Cells/metabolism ; Obesity/drug therapy/*metabolism ; Receptor, Melatonin, MT2/genetics/*metabolism ; Receptors, Adrenergic, alpha-1/genetics/*metabolism ; Receptors, Prostaglandin/genetics/*metabolism

OBJECTIVETo investigate the effect of prostaglandin E2 (PGE(2)) on the proliferation of cultured hepatocellular carcinoma cells and explore which subtypes of EP prostanoid receptor mediate the action.

METHODSRT-PCR was used to determine COX-2 and EP receptor mRNA expression levels in human hepatocellular carcinoma cell line Hep3B and human normal hepatocyte line QSG7701. Cell counting kit-8 (CCK-8) assay was employed to investigate the effect of PGE(2), selective EP2 receptor agonist butaprost and EP3/EP4 receptor agonist PGE1 alcohol on the proliferation of the cells.

RESULTSCOX-2 mRNA was highly expressed in Hep3B cells but scarcely in QSG7701 cells. Hep3B cells expressed the mRNAs for all the EP receptor subtypes, but EP2 and EP4 receptors were much more strongly expressed than EP1 and EP3 receptors. PGE(2) significantly promoted Hep3B cell proliferation in a time- and dose-dependent manner, and 10 µmol/L PGE(2) increased the cell proliferation by 22.57% (P<0.001) after a 48-h incubation; treatment with 0.1, 1.0, and 10 µmol/L PGE(2) for 72 h resulted in significantly increased cell proliferation by 12.13% (P<0.01), 17.58% (P<0.01) and 33.07% (P<0.001), respectively. EP2 receptor agonist butaprost (20 µmol/L) increased Hep3B cell proliferation by 21.96% (P<0.001), but the EP3/EP4 receptor agonist PGE(1) alcohol (2-20 µmol/L) exhibited no significant mitogenic effect in Hep3B cells, and 200 µmol/L PGE(1) alcohol decreased the cell viability.

CONCLUSIONSelective activation of EP2 receptor promotes Hep3B cell proliferation, indicating the predominant role of EP2 receptor in mediating the mitogenic effect of PGE2.

Carcinoma, Hepatocellular ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; genetics ; metabolism ; Dinoprostone ; pharmacology ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Male ; RNA, Messenger ; genetics ; Receptors, Prostaglandin E, EP2 Subtype ; genetics ; metabolism

In this investigation, we studied the expression and localization of rat prostaglandin F (FP) receptor in uterine tissues of rats on gestational Days 10, 15, 18, 20, 21, 21.5 and postpartal Days 1 and 3 using Western blotting analysis, real-time PCR, and immunohistochemistry. A high level of immunoreactivity was observed on gestational Days 20, 21, and 21.5 with the most significant signals found on Day 20. FP receptor protein was expressed starting on gestational Day 15, and a fluctuating unsteady increase was observed until delivery. Uterine FP receptor mRNA levels were low between Days 10 and 18 of gestation (p < 0.05). The transcript level increased significantly on Day 20 and peaked on Day 21.5 just before labor (p < 0.05). There was a positive correlation between FP receptor mRNA expression and serum estradiol levels (rs = 0.78; p < 0.01) along with serum estradiol/progesterone ratios (rs = 0.79; p < 0.01). In summary, we observed an increase FP receptor expression in rat uterus with advancing gestation, a marked elevation of expression at term, and a concominant decrease during the postpartum period. These findings indicate a role for uterine FP receptors in the mediation of uterine contractility at term.
Animals ; Blotting, Western ; Female ; *Gene Expression Regulation ; Gestational Age ; Immunoglobulin G/blood ; Immunohistochemistry ; Postpartum Period/metabolism ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Receptors, Prostaglandin/*genetics/metabolism ; Uterus/*metabolism

OBJECTIVE[corrected] To investigate the effect of peroxisome proliferator-activated receptors (PPARs) activators on plasminogen activator inhibitor type-1 (PAI-1) expression in human umbilical vein endothelial cells and the possible mechanism.

METHODSHuman umbilical vein endothelial cells (HUVECs) were obtained from normal fetus, and cultured conventionally. Then the HUVECs were exposed to test agents (linolenic acid, linoleic acid, oleic acid, stearic acid and prostaglandin J2 respectively) in varying concentrations with fresh media. RT-PCR and ELISA were applied to determine the expression of PPARs and PAI-1 in HUVECs.

RESULTSPPAR alpha, PPAR beta and PPAR gamma mRNA were detected by using RT-PCR in HUVECs. Treatment of HUVECs with PPARalpha and PPAR gamma activators--linolenic acid, linoleic acid, oleic acid and prostaglandin J2 respectively, but not with stearic acid could augment PAI-1 mRNA expression and protein secretion in a concentration-dependent manner. However, the mRNA expressions of 3 subclasses of PPAR with their activators in HUVECs were not changed compared with controls.

CONCLUSIONHUVECs express PPARs. PPARs activators may increase PAI-1 expression in ECs, but the underlying mechanism remains unclear. Although PPARs expression was not enhanced after stimulated by their activators in ECs, the role of functionally active PPARs in regulating PAI-1 expression in ECs needs to be further investigated by using transient gene transfection assay.

Cells, Cultured ; Endothelium, Vascular ; cytology ; metabolism ; Fatty Acids ; pharmacology ; Fetus ; Humans ; Linoleic Acid ; pharmacology ; Plasminogen Activator Inhibitor 1 ; biosynthesis ; genetics ; Prostaglandin D2 ; analogs & derivatives ; pharmacology ; RNA, Messenger ; genetics ; Receptors, Cytoplasmic and Nuclear ; biosynthesis ; genetics ; Transcription Factors ; biosynthesis ; genetics ; Umbilical Veins ; cytology ; metabolism ; alpha-Linolenic Acid ; pharmacology

BACKGROUNDThe level of basic fibroblast growth factor (bFGF) increases rapidly after cerebral ischemia. However, the molecular mechanisms for the effects of bFGF on cerebral microvascular endothelial cells (cMVECs) have not yet been fully elucidated. In this study, a murine cMVEC line, bEnd.3, was employed to study the effects of bFGF on cyclooxygenase (COX) expression and its downstream effects in cMVECs.

METHODSAfter treatment with bFGF, RT-PCR and Western blotting analyses were carried out to evaluate the changes in COX-2 mRNA and protein expression, respectively. MTT assays were performed to measure cell proliferation. The prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) concentrations in the culture medium were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTSCOX-2 mRNA and protein expressions in bEnd.3 cells were induced by bFGF in time- and dose-dependent manners. The bFGF-induced COX-2 upregulation led to enhanced PGE2 production by bEnd.3 cells, and this effect was abolished by the selective COX-2 inhibitor NS-398. bFGF also increased VEGF production by bEnd.3 cells, and this effect was blocked by NS-398 and the EP1/2 (PGE2 receptors) antagonist AH6809. Furthermore, exogenous PGE2 increased VEGF production in bEnd.3 cells, and AH6809 blocked this effect.

CONCLUSIONbFGF increases VEGF production in an autocrine manner by increasing COX-2-generated PGE2 in cMVECs and subsequently stimulates MVEC proliferation and angiogenesis.

Blotting, Western ; Cell Line ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; genetics ; metabolism ; physiology ; Dinoprostone ; metabolism ; pharmacology ; Endothelial Cells ; cytology ; drug effects ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Fibroblast Growth Factor 2 ; pharmacology ; Humans ; Receptors, Prostaglandin E ; antagonists & inhibitors ; Reverse Transcriptase Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A ; metabolism ; Xanthones ; pharmacology

This study investigated the effect of advanced glycation end products (AGEs) on differentiation of naïve CD4(+) T cells and the role of the receptor of AGEs (RAGE) and peroxisome proliferator-activated receptors (PPARs) activity in the process in order to gain insight into the mechanism of immunological disorders in diabetes. AGEs were prepared by the reaction of bovine serum albumin (BSA) with glucose. Human naïve CD4(+) T cells, enriched from blood of healthy adult volunteers with negative selection assay, were cultured in vitro and treated with various agents including AGEs, BSA, high glucose, PGJ2 and PD68235 for indicated time. In short hairpin (sh) RNA knock-down experiment, naïve CD4(+) T cells were transduced with media containing shRNA-lentivirus generated from lentiviral packaging cell line, Lent-X(TM) 293 T cells. Surface and intracellular cytokine stainings were used for examination of CD4(+) T cell phenotypes, and real-time PCR and Western blotting for detection of transcription factor mRNA and protein expression, respectively. The suppressive function of regulatory T (Treg) cells was determined by a [(3)H]-thymidine incorporation assay. The results showed that AGEs induced higher pro-inflammatory Th1/Th17 cells differentiated from naïve CD4(+) T cells than the controls, whereas did not affect anti-inflammatory Treg cells. However, AGEs eliminated suppressive function of Treg cells. In addition, AGEs increased RAGE mRNA expression in naïve CD4(+) T cells, and RAGE knock-down by shRNA eliminated the effect of AGEs on the differentiation of CD4(+) T cells and the reduction of suppressive function of Treg cells. Furthermore, AGEs inhibited the mRNA expression of PPARγ, not PPARα PPARγ agonist, PGJ2, inhibited the effect of AGEs on naïve CD4(+) T cell differentiation and reversed the AGE-reduced suppressive function of Treg cells; on the other hand, PPARγ antagonist, PD68235, attenuated the blocking effect of RAGE shRNA on the role of AGEs. It was concluded that AGEs may promote CD4(+) T cells development toward pro-inflammatory state, which is associated with increased RAGE mRNA expression and reduced PPARγ activity.
Adult ; Animals ; Blotting, Western ; CD4-Positive T-Lymphocytes ; drug effects ; metabolism ; Cattle ; Cell Differentiation ; drug effects ; Cells, Cultured ; Glucose ; pharmacology ; Glycation End Products, Advanced ; pharmacology ; HEK293 Cells ; Humans ; Interferon-gamma ; metabolism ; Interleukin-17 ; metabolism ; PPAR gamma ; agonists ; genetics ; metabolism ; Prostaglandin D2 ; analogs & derivatives ; pharmacology ; RNA Interference ; Receptor for Advanced Glycation End Products ; Receptors, Immunologic ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Serum Albumin, Bovine ; pharmacology ; T-Lymphocytes, Regulatory ; drug effects ; metabolism ; Th1 Cells ; drug effects ; metabolism ; Th17 Cells ; drug effects ; metabolism