prostaglandin-d2 and Diabetes-Mellitus

Topics: Biomarkers; Cardiovascular Diseases; Diabetes Mellitus; Enzyme-Linked Immunosorbent Assay; Humans; Kidney Diseases; Mass Spectrometry; Prognosis; Prostaglandin D2; Radioimmunoassay; Reference Values; Specimen Handling

Prostaglandin D(2) (PGD(2)) and its metabolites bind to the intracellular PPARs to regulate vasoactive substances involved in vascular remodeling through regulation of mRNAs transcription as well as through receptor-mediated mechanisms. PGD(2) decreases inducible NO, PAI-1, endothelin, and VCAM expression through inhibition to NF kappa B, STAT, or AP-1 transcription factors, which are regulated by cytokines/immune system. Moreover, transfer of L-PGDS (PGD(2) synthase) into the intracellular space of EC or SMC increases intracellular PGD(2), thereby decreasing these substances. PGD(2) attenuates in vivo organ injury mediated by cytokines and the immune system. The pretreatment with PGD(2) attenuates the liver damage and hemodynamic collapse following LPS. Dahl salt-sensitive rats, with decreased PGD(2) in the outer medulla of the kidney, are prone to hypertensive kidney injury. Serum L-PGDS level is increased in renal dysfunction through a decrease in glomerular filtration. L-PGDS in urine may be derived from a failure of tubular reabsorption or from in situ synthesis. Urinary L-PGDS excretion markedly increases in the early stage of kidney injury, and urinary L-PGDS is a useful predictor of the forthcoming renal injury. Indeed, urinary L-PGDS precedes clinically overt proteinuria or other parameters indicating renal dysfunction in hypertension, primary renal diseases, and diabetes in humans. PGD(2)/L-PGDS system is a Cinderella of vascular biology.

Topics: Animals; Diabetes Mellitus; Humans; Hypertension; Intramolecular Oxidoreductases; Kidney Diseases; Lipocalins; Prostaglandin D2; Rats

Laropiprant, an antagonist of the PGD(2) receptor, DP1, is effective in reducing the flushing symptoms associated with extended-release (ER) niacin and thereby improves the tolerability of niacin therapy for dyslipidemia. Because PGD(2) has been reported to inhibit platelet aggregation in vitro, it has been speculated that antagonism of DP1 may enhance platelet reactivity. Three clinical studies evaluated the potential effect of laropiprant, with or without coadministration of ER niacin, on in vivo platelet function in healthy subjects and hypercholesterolemic or diabetic subjects by measuring urinary levels of 11-dehydrothromboxane B(2) (11-dTxB(2)), a marker of in vivo platelet activation. Following 7 days of multiple-dose administration, coadministration of laropiprant with ER niacin did not increase urinary 11-dTxB(2) levels compared to ER niacin alone in healthy, hypercholesterolemic, or diabetic subjects. In hypercholesterolemic and diabetic subjects, laropiprant did not increase urinary 11-dTxB(2) levels compared to placebo. These results demonstrate that laropiprant does not enhance in vivo platelet reactivity, either alone or in combination with niacin.

Topics: Adolescent; Adult; Aged; Biomarkers; Blood Platelets; Cross-Over Studies; Delayed-Action Preparations; Diabetes Mellitus; Double-Blind Method; Epoprostenol; Female; Humans; Hypercholesterolemia; Indoles; Male; Middle Aged; Niacin; Platelet Activation; Prostaglandin D2; Receptors, Immunologic; Receptors, Prostaglandin; Thromboxane B2; Young Adult

Maternal diabetes is associated with morphological placental abnormalities and foeto-placental impairments. These alterations are linked with a dysregulation of the activity of matrix metalloproteinases (MMPs). We investigated the action of 15deoxyDelta(12,14) prostaglandin J(2) (15dPGJ(2)), a natural ligand of the peroxisome proliferator activated receptor (PPAR) gamma, on MMP-2 and MMP-9 activities and tissue inhibitors of matrix metalloproteinases (TIMP) levels in foetuses and placentas from diabetic rats.. Diabetes was induced in rat neonates by a single streptozotocin administration (90 mg kg(-1) s.c.). At 13.5 days of gestation, foetal and placental homogenates were prepared for the determination of PPARgamma levels (western blot) and 15dPGJ(2) concentration (enzyme-immunoassay), whereas the in vitro effect of 15dPGJ(2) (2 microM) was evaluated on placental and foetal MMPs and TIMP activities (zymography and reverse zymography), nitrate/nitrite concentrations (Griess method) and thiobarbituric acid reactive substances (TBARS).. PPARgamma was increased while 15dPGJ(2) was decreased in placentas and foetuses from diabetic rats. 15dPGJ(2) additions were able to reduce the high activities of MMP-2 and MMP-9 present in diabetic placental tissues. 15dPGJ(2) additions reduced MMP-2 activity in control and diabetic foetuses. TIMP-3 levels were decreased in diabetic placentas and 15dPGJ(2) was able to enhance them to control values. Nitrates/nitrites and TBARS, metabolites of MMPs activators, were increased in the diabetic placenta and reduced by 15dPGJ(2).. This study demonstrates that 15dPGJ(2) is a potent modulator of the balance between MMP activities and TIMP levels, which is needed in the correct formation and function of the placenta and foetal organs.

Topics: Animals; Diabetes Mellitus; Disease Models, Animal; Female; Fetus; Gelatinases; Matrix Metalloproteinases; Nitric Oxide; Placenta; PPAR gamma; Pregnancy; Prostaglandin D2; Rats; Rats, Wistar; Tissue Inhibitor of Metalloproteinases

Previously, we demonstrated that lipocalin-type prostaglandin D(2) synthase (L-PGDS) knockout mice become glucose intolerant and display signs of diabetic nephropathy and accelerated atherosclerosis. In the current study we sought to explain the link between L-PGDS and glucose tolerance. Using the insulin-sensitive rat skeletal muscle cell line, L6, we showed that L-PGDS could stimulate glucose transport approximately 2-fold as well as enhance insulin-stimulated glucose transport, as measured by 2-deoxy-[(3)H]-glucose uptake. The increased glucose transport was not attributed to increased GLUT4 production but rather the stimulation of GLUT4 translocation to the plasma membrane, a phenomenon that was lost when cells were cultured under hyperglycemic (20 mM) conditions or pretreated with wortmannin. There was however, an increase in GLUT1 expression as well as a 3-fold increase in hexokinase III expression, which was increased to nearly 5-fold in the presence of insulin, in response to L-PGDS at 20 mM glucose. In addition, adipocytes isolated from L-PGDS knockout mice were significantly less sensitive to insulin-stimulated glucose transport than wild-type. We conclude that L-PGDS, via production of prostaglandin D(2), is an important mediator of muscle and adipose glucose transport which is modulated by glycemic conditions and plays a significant role in the glucose intolerance associated with type 2 diabetes.

Topics: Adipocytes; Animals; Biological Transport; Cell Line; Diabetes Mellitus; Gene Expression Regulation, Enzymologic; Glucose; Glucose Transporter Type 4; Hyperglycemia; Insulin; Intramolecular Oxidoreductases; Lipocalins; Male; Mice; Mice, Knockout; Muscles; Phosphatidylinositol 3-Kinases; Prostaglandin D2; Rats; Signal Transduction

Platelet sensitivity to antiaggregatory prostaglandins (PGI2, PGE1, PGD2) was studied in 143 patients (122 male) with angiographically proven peripheral vascular disease and compared with age-matched clinically normal controls. Patients had a significantly lower platelet sensitivity to PGI2, PGE1, and PGD2 than controls. Clinical stages had no significant influence on the platelet sensitivity to PGI2 and PGE1. Patients with stage IIa had a lower sensitivity to PGD2 than patients with stage IV, the difference not being significant. Analyzing the influence of risk factors like diabetes, hyperlipoproteinemia, or smoking, there seemed to be an inverse relation between risk factors and platelet sensitivity to PGI2 and PGE1. Smokers especially, together with smokers exhibiting an additional risk factor, exhibited the highest prostaglandin consumption (PGI2, PGE1) and therefore the lowest platelet sensitivity. However, it has to be emphasized that the differences were not significant. There was a significant correlation between platelet sensitivity to PGI2 and PGE1, whereas this was not the case between the respective sensitivities to PGI2 and PGD2. This supports the hypothesis that both these prostaglandins (PGI2, PGE1) share the same receptor on the platelet surface, whereas PGD2 has its own receptor.

Topics: Adenosine Diphosphate; Aged; Alprostadil; Blood Platelets; Diabetes Mellitus; Epoprostenol; Female; Humans; Hyperlipoproteinemias; Male; Middle Aged; Platelet Aggregation; Prostaglandin D2; Prostaglandins D; Prostaglandins E; Risk; Smoking; Vascular Diseases

Inhibition of collagen-induced platelet aggregation by either endothelial extracts, prostacyclin, prostaglandin E1 or prostaglandin D2 was investigated. The inhibition was less efficient with diabetic platelets than with platelets from normal donors. The refractoriness of diabetic platelets to inhibitory prostaglandins was observed both with platelet-rich plasma and platelets isolated from their plasma. Moreover levels of cyclic AMP in resting platelets and after stimulation by either PGE1 or PGD2 were lower in diabetic platelets than in normal platelets. It is concluded that the weaker response of diabetic platelets to inhibitory prostaglandins could be related to their content in cyclic AMP.

Topics: Adolescent; Adult; Alprostadil; Collagen; Cyclic AMP; Diabetes Mellitus; Epoprostenol; Female; Humans; Male; Middle Aged; Platelet Aggregation; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E