Gastrin-Releasing Peptide Receptor Antagonism Induces Protection from Lethal Sepsis: Involvement of Toll-like Receptor 4 Signaling

In sepsis, toll-like receptor (TLR)-4 modulates the migration of neutrophils to infectious foci, favoring bacteremia and mortality. In experimental sepsis, organ dysfunction and cytokines released by activated macrophages can be reduced by gastrin-releasing peptide (GRP) receptor (GRPR) antagonist RC-3095. Here we report a link between GRPR and TLR-4 in experimental models and in sepsis patients. RAW 264.7 culture cells were exposed to lipopolysaccharide (LPS) or tumor necrosis factor (TNF)-alpha and RC-3095 (10 ng/mL), Male Wistar rats were subjected to cecal ligation and puncture (CLP), and RC-3095 was administered (3 mg/kg, subcutaneously); after 6 h, we removed the blood, bronchoalveolar lavage, peritoneal lavage and lung. Human patients with a clinical diagnosis of sepsis received a continuous infusion with RC-3095 (3 mg/kg, intravenous) over a period of 12 h, and plasma was collected before and after RC-3095 administration and, in a different set of patients with systemic inflammatory response syndrome (SIRS) or sepsis. GRP plasma levels were determined. RC-3095 inhibited TLR-4, extracellular-signal-related kinase (ERK)-1/2, Jun NH2-terminal kinase (JNK) and Akt and decreased activation of activator protein 1 (AP-1), nuclear factor (NF)-kappa B and interleukin (IL)-6 in macrophages stimulated by LPS. It also decreased IL-6 release from macrophages stimulated by TNF-alpha. RC-3095 treatment in CLP rats decreased lung TLR-4, reduced the migration of cells to the lung and reduced systemic cytokines and bacterial dissemination. Patients with sepsis and systemic inflammatory response syndrome have elevated plasma levels of GRP which associates with clinical outcome in the sepsis patients. These findings highlight the role of GRPR signaling in sepsis outcome and the beneficial action of GRPR antagonists in controlling the inflammatory response in sepsis through a mechanism involving at least inhibition of TLR-4 signaling. Online address: http://www.molmed.org doi: 10.2119/molmed.2012.00083

Cannabinoid CB1 receptor mediates glucocorticoid effects on hormone secretion induced by volume and osmotic changes

1. The present study provides the first in vivo evidence that the cannabinoid CB1 receptor mediates the effects of dexamethasone on hormone release induced by changes in circulating volume and osmolality. Male adult rats were administered with the CB1 receptor antagonist rimonabant (10 mg/Kg, p.o.), followed or not in 1 hour by dexamethasone (1 mg/Kg, i.p.). Extracellular volume expansion (EVE, 2 mL/100 g of body weight, i.v.) was performed 2 hours after dexamethasone or vehicle treatment using either isotonic (I-EVE, 0.15 mol/L) or hypertonic (H-EVE, 0.30 mol/L) NaCl solution. Five minutes after EVE, animals were decapitated and trunk blood was collected for all plasma measurements. 2. Rimonabant potentiated oxytocin (OT) secretion induced by H-EVE and completely reversed the inhibitory effects of dexamethasone in response to the same stimulus. These data suggest that glucocorticoid modulation of OT release is mediated by the CB1 receptor. 3. Although dexamethasone did not affect vasopressin (AVP) secretion induced by H-EVE, the administration of rimonabant potentiated AVP release in response to the same stimulus, supporting the hypothesis that the CB1 receptor regulates AVP secretion independently of glucocorticoid-mediated signalling. 4. Dexamethasone alone did not affect atrial natriuretic peptide (ANP) release stimulated by I-EVE or H-EVE. However, pretreatment with rimonabant potentiated ANP secretion induced by H-EVE, suggesting a possible role for the CB1 receptor in the control of peripheral factors that modulate cardiovascular function. 5. Rimonabant also reversed the inhibitory effects of dexamethasone on H-EVE-induced corticosterone secretion, reinforcing the hypothesis that the CB1 receptor may be involved in the negative feedback exerted by glucocorticoids on the activity of the hypothalamicpituitaryadrenal axis. 6. Collectively, the results of the present study indicate that the CB1 receptor modulates neurohypophyseal hormone secretion and systemic factors, such as corticosterone and ANP, thus participating in homeostatic responses to altered extracellular volume and plasma tonicity.

Thyroid hormone profile in breast cancer patients in postmenopause

Objective: The aim of this study was to determine thyroid hormone (TH) profile in postmenopausal patients with breast cancer (BC). Subjects and methods: 12 CaM patients stages I or II, without interventions that could interfere with tumor progression were selected, as well as and a control group with 18 postmenopausal women without CaM. We measured serum anti-thyroperoxidase antibody (TPOAB), thyroid-stimulating hormone (TSH), free thyroxine (T4L), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), before and after surgery, besides immunohistochemistry for estrogen (ER) and progesterone (PR) receptors. Results: Four patients with CaM showed changes in thyroid hormone profile: two had hyperthyroidism, one hypothyroidism, and one was positive for TPO-AB. All of them positive for ER and PR.TSH levels in breast cancer patients were not different from levels found in the control group (1.89 +/- 1.56 vs. 2.86 +/- 3.12 mIU/mL), but the levels of T4L in patients with CaM were statistically higher than those of the control group (1.83 +/- 0.57 vs. 1.10 +/- 0.20 ng/dL). Conclusion: These results reinforce the need for assessment of thyroid status in CaM patients, since in the absence of E2, changes in clinical HTs can act in E2-controlled processes. Arq Bras Endocrinol Metab. 2012;56(4):238-43

Effects of the etonogestrel-releasing contraceptive implant inserted immediately postpartum on maternal hemostasis: A randomized controlled trial

Introduction: The puerperium is the period of highest risk for thrombosis during a woman's reproductive life and it is an important time for initiating an effective contraceptive method in order to increase intergestational interval. Thus, the objective of the present study was to evaluated the effects of the etonogestrel (ENG)-releasing contraceptive implant inserted immediately postpartum on maternal hemostasis markers during the first six weeks of delivery. Materials and Methods: Forty healthy women aged 18 to 35 years-old were randomized to receive either the ENG-releasing implant 24-48 h after delivery (implant group; n=20) or nothing (control group) until the sixth postpartum week. Blood samples were collected at 24-48 h and at 6 weeks after delivery, and hemostatic variables, including fibrinogen, coagulation factors, protein C, free protein S, antithrombin, alpha 2-antiplasmin, plasminogen activator inhibitor 1, thrombin-antithrombin complex (TAT), prothrombin fragment (PF)1+2, and D-dimers, as well as normalized activated protein C sensitivity ratio (nAPCsr), thrombin time, activated partial thromboplastin time, and prothrombin time were evaluated. Results: Insertion of the ENG-releasing contraceptive implant did not change the physiological reduction in overall coagulation (TAT and PF1+2) and fibrinolysis (D-dimer) markers, or nAPCsr. Reductions in factors II, VII, X and fibrinogen and increases in factor V were greater in the control than in the implant group. Clotting factors remained within normal limits throughout the study. Conclusion: The ENG-releasing contraceptive implant inserted immediately postpartum did not have negative effects on physiological variations of the hemostatic system during the first 6 weeks postpartum. (C) 2012 Elsevier Ltd. All rights reserved.

Signaling Events During Cyclic Guanosine Monophosphate-Regulated Pigment Aggregation in Freshwater Shrimp Chromatophores

Crustacean color change results partly from granule aggregation induced by red pigment concentrating hormone (RPCH). In shrimp chromatophores, both the cyclic GMP (3', 5'-guanosine monophosphate) and Ca2+ cascades mediate pigment aggregation. However, the signaling elements upstream and downstream from cGMP synthesis by GC-S (cytosolic guanylyl cyclase) remain obscure. We investigate post-RPCH binding events in perfused red ovarian chromatophores to disclose the steps modulating cGMP concentration, which regulates granule translocation. The inhibition of calcium/calmodulin complex (Ca2+/CaM) by N-(6-aminohexyl)-5-chloro-1-naphthalenesulphonamide (W7) induces spontaneous aggregation but inhibits RPCH-triggered aggregation, suggesting a role in pigment aggregation and dispersion. Nitric oxide synthase inhibition by N omega-nitro-L-arginine methyl ester hydrochloride (L-NAME) strongly diminishes RPCH-induced aggregation; protein kinase G inhibition (by rp-cGMPs-triethylamine) reduces RPCH-triggered aggregation and provokes spontaneous dispersion, disclosing NO/PKG participation in aggregation signaling. Myosin light chain phosphatase inhibition (by cantharidin) accelerates RPCH-triggered aggregation, whereas Rho-associated protein kinase inhibition (by Y-27632, H-11522) reduces RPCH-induced aggregation and accelerates dispersion. MLCP (myosin light chain kinase) and ROCK (Rho-associated protein kinase) may antagonistically regulate myosin light chain (MLC) dephosphorylation/phosphorylation during pigment dispersion/aggregation. We propose the following general hypothesis for the cGMP/Ca2+ cascades that regulate pigment aggregation in crustacean chromatophores: RPCH binding increases Ca2+ (int), activating the Ca2+/CaM complex, releasing NOS-produced nitric oxide, and causing GC-S to synthesize cGMP that activates PKG, which phosphorylates an MLC activation site. Myosin motor activity is initiated by phosphorylation of an MLC regulatory site by ROCK activity and terminated by MLCP-mediated dephosphorylation. Qualitative comparison reveals that this signaling pathway is conserved in vertebrate and invertebrate chromatophores alike.

Combined oral contraceptives and increasing cardiovascular risk: thromboembolism and hypertension

Background: Hormonal contraceptive pills are the most used reversible method for familiar planning in Brazil. The combined pill, with synthetic analogs of estrogen and progestin, is employed by 25% of Brazilian female population. Its use provokes an increase of blood pressure levels, takes patient to a hipercoagulability state and predisposes her to thromboembolic events. Purposes: We aimed to describe mechanisms of hypercoagulability promoted by oral combined contraceptives, to analyze the relative risk of cardiovascular events within users and to list the most common circulatory pathologies in these patients. Methods: Three virtual medical databases were surveyed (Pubmed/Medline, BVS/LILACS and Scielo). Twelve studies were selected: clinical trials, case reports and articles of indexed medical periodic originally published in Portuguese and English about synthetic hormones, oral contraception, coagulation disorders and cardiovascular morbimortality. Results: Synthetic estrogen promotes an increase of some clotting factors' levels (VII, VIII, IX, X, XII, XIII and fibrinogen), such as a reduction of their inhibitors (S protein and antithrombin). Because of this, etinilestradiol is the component most related to venous thrombosis and ischemic diseases of brain and heart. It also improves the releasing of hepatic angiotensinogen, taking to a increase of blood pressure levels. Conclusions: The prescription of oral combined contraceptives needs criteria, notably due to adverse effects of etinilestradiol. It is recommended to avoid the administration of these drugs for patients elder than 35 year-old or with risk factors. For these patients, the use of progestagen-only pills seems to be safer.

Parathyroid hormone and phosphorus overload in uremia: impact on cardiovascular system

Background. Cardiac remodeling in uremia is characterized by left ventricular hypertrophy, interstitial fibrosis and microvascular disease. Cardiovascular disease is the leading cause of death in uremic patients, but coronary events alone are not the prevalent cause, sudden death and heart failure are. We studied the cardiac remodeling in experimental uremia, evaluating the isolated effect of parathyroid hormone (PTH) and phosphorus. Methods. Wistar rats were submitted to parathyroidectomy (PTx) and 5/6 nephrectomy (Nx); they also received vehicle (V) and PTH at normal (nPTH) or high (hPTH) doses. They were fed with a poor-phosphorus (pP) or rich-phosphorus (rP) diet and were divided into the following groups: 'Sham': G1 (V + normal-phosphorus diet (np)) and 'Nx + PTx': G2 (nPTH + pP), G3 (nPTH + rP), G4 (hPTH + pP) and G5 (hPTH + rP). After 8 weeks, biochemical analysis, myocardium morphometry and arteriolar morphological analysis were performed. In addition, using immunohistochemical analysis, we evaluated angiotensin II, alpha-actin, transforming growth factor-beta (TGF-beta) and nitrotyrosine, as well as fibroblast growth factor-23 (FGF-23), fibroblast growth factor receptor-1 (FGFR-1) and runt-related transcription factor-2 (Runx-2) expression. Results. Nx animals presented higher serum creatinine levels as well as arterial hypertension. Higher PTH levels were associated with myocardial hypertrophy and fibrosis as well as a higher coronary lesion score. High PTH animals also presented a higher myocardial expression of TGF-beta, angiotensin II, FGF-23 and nitrotyrosine and a lower expression of alpha-actin. Phosphorus overload was associated with higher serum FGF-23 levels and Runx-2, as well as myocardial hypertrophy. FGFR-1 was positive in the cardiomyocytes of all groups as well as in calcified coronaries of G4 and G5 whereas Runx-2 was positive in G3, G4 and G5. Conclusion. In uremia, PTH and phosphorus overload are both independently associated with major changes related to the cardiac remodeling process, emphasizing the need for a better control of these factors in chronic kidney disease.

Gastrin-releasing peptide receptor (GRPR) mediates chemotaxis in neutrophils

Neutrophil migration to inflamed sites is crucial for both the initiation of inflammation and resolution of infection, yet these cells are involved in perpetuation of different chronic inflammatory diseases. Gastrin-releasing peptide (GRP) is a neuropeptide that acts through G protein coupled receptors (GPCRs) involved in signal transmission in both central and peripheral nervous systems. Its receptor, gastrin-releasing peptide receptor (GRPR), is expressed by various cell types, and it is overexpressed in cancer cells. RC-3095 is a selective GRPR antagonist, recently found to have antiinflammatory properties in arthritis and sepsis models. Here we demonstrate that i.p. injection of GRP attracts neutrophils in 4 h, and attraction is blocked by RC-3095. Macrophage depletion or neutralization of TNF abrogates GRP-induced neutrophil recruitment to the peritoneum. In vitro, GRP-induced neutrophil migration was dependent on PLC-beta 2, PI3K, ERK, p38 and independent of G alpha i protein, and neutrophil migration toward synovial fluid of arthritis patients was inhibited by treatment with RC-3095. We propose that GRPR is an alternative chemotactic receptor that may play a role in the pathogenesis of inflammatory disorders.

Growth hormone pharmacogenetics: the interactive effect of a microsatellite in the IGF1 promoter region with the GHR-exon 3 and-202 A/C IGFBP3 variants on treatment outcomes of children with severe GH deficiency

Insulin-like growth factor type 1 (IGF1) is a mediator of growth hormone (GH) action, and therefore, IGF1 is a candidate gene for recombinant human GH (rhGH) pharmacogenetics. Lower serum IGF1 levels were found in adults homozygous for 19 cytosine-adenosine (CA) repeats in the IGF1 promoter. The aim of this study was to evaluate the influence of (CA)n IGF1 polymorphism, alone or in combination with GH receptor (GHR)-exon 3 and -202 A/C insulin-like growth factor binding protein-3 (IGFBP3) polymorphisms, on the growth response to rhGH therapy in GH-deficient (GHD) patients. Eighty-four severe GHD patients were genotyped for (CA) n IGF1, -202 A/C IGFBP3 and GHR-exon 3 polymorphisms. Multiple linear regressions were performed to estimate the effect of each genotype, after adjustment for other influential factors. We assessed the influence of genotypes on the first year growth velocity (1st y GV) (n = 84) and adult height standard deviation score (SDS) adjusted for target-height SDS (AH-TH SDS) after rhGH therapy (n = 37). Homozygosity for the IGF1 19CA repeat allele was negatively correlated with 1st y GV (P = 0.03) and AH-TH SDS (P = 0.002) in multiple linear regression analysis. In conjunction with clinical factors, IGF1 and IGFBP3 genotypes explain 29% of the 1st y GV variability, whereas IGF1 and GHR polymorphisms explain 59% of final height-target-height SDS variability. We conclude that homozygosity for IGF1 (CA) 19 allele is associated with less favorable short-and long-term growth outcomes after rhGH treatment in patients with severe GHD. Furthermore, this polymorphism exhibits a non-additive interaction with -202 A/C IGFBP3 genotype on the 1st y GV and with GHR-exon 3 genotype on adult height. The Pharmacogenomics Journal (2012) 12, 439-445; doi:10.1038/tpj.2011.13; published online 5 April 2011

Atorvastatin and hormone therapy effects on APOE mRNA expression in hypercholesterolemic postmenopausal women

Menopause is associated with changes in lipid levels resulting in increased risk of atherosclerosis and cardiovascular events. Hormone therapy (HT) and atorvastatin have been used to improve lipid profile in postmenopausal women. Effects of HT, atorvastatin and APOE polymorphisms on serum lipids and APOE and LXRA expression were evaluated in 87 hypercholesterolemic postmenopausal women, randomly selected for treatment with atorvastatin (AT, n=17), estrogen or estrogen plus progestagen (HT, n=34) and estrogen or estrogen plus progestagen associated with atorvastatin (HT+AT, n=36). RNA was extracted from peripheral blood mononuclear cells (PBMC) and mRNA expression was measured by TaqMan (R) PCR. APOE epsilon 2/epsilon 3/epsilon 4 genotyping was performed using PCR-RFLP. Total cholesterol (TC). LDL-c and apoB were reduced after each treatment (p<0.001). Triglycerides, VLDL-c and apoAl were reduced only after atorvastatin (p<0.05), whereas triglycerides and VLDL-c were increased after HT (p=0.01). HT women had lower reduction on TC, LDL-c and apoB than AT and HT+AT groups (p<0.05). APOE mRNA expression was reduced after atorvastatin treatment (p=0.03). Although LXRA gene expression was not modified by atorvastatin, it was correlated with APOE mRNA before and after treatments. Basal APOE mRNA expression was not influenced by gene polymorphisms, however the reduction on APOE expression was more pronounced in epsilon 3 epsilon 3 than in epsilon 3 epsilon 4 carriers. Atorvastatin down-regulates APOE mRNA expression and it is modified by APOE genotypes in PBMC from postmenopausal women. (C) 2011 Elsevier Ltd. All rights reserved.

Norepinephrine stimulates progesterone production in highly estrogenic bovine granulosa cells cultured under serum-free, chemically defined conditions

Background: Since noradrenergic innervation was described in the ovarian follicle, the actions of the intraovarian catecholaminergic system have been the focus of a variety of studies. We aimed to determine the gonadotropin-independent effects of the catecholamine norepinephrine (NE) in the steroid hormone profile of a serum-free granulosa cell (GC) culture system in the context of follicular development and dominance. Methods: Primary bovine GCs were cultivated in a serum-free, chemically defined culture system supplemented with 0.1% polyvinyl alcohol. The culture features were assessed by hormone measurements and ultrastructural characteristics of GCs. Results: GCs produced increasing amounts of estradiol and pregnenolone for 144h and maintained ultrastructural features of healthy steroidogenic cells. Progesterone production was also detected, although it significantly increased only after 96h of culture. There was a highly significant positive correlation between estradiol and pregnenolone production in high E2-producing cultures. The effects of NE were further evaluated in a dose response study. The highest tested concentration of NE (10 (-7) M) resulted in a significant increase in progesterone production, but not in estradiol or pregnenolone production. The specificity of NE effects on progesterone productio n was further investigated by incubating GCs with propranolol (10 (-8) M), a non-selective beta-adrenergic antagonist. Conclusions: The present culture system represents a robust model to study the impact of intrafollicular factors, such as catecholamines, in ovarian steroidogenesis and follicular development. The results of noradrenergic effects in the steroidogenesis of GC have implications on physiological follicular fate and on certain pathological ovarian conditions such as cyst formation and anovulation.

Molting dynamics and juvenile hormone titer profiles in the nymphal stages of a lower termite, Cryptotermes secundus (Kalotermitidae) - signatures of developmental plasticity

Termites are social cockroaches and this sociality is founded on a high plasticity during development. Three molting types (progressive, stationary and regressive molts) are fundamental to achieve plasticity during alate/sexual development, and they make termites a major challenge to any model on endocrine regulation in insect development. As the endocrine signatures underpinning this plasticity are barely understood, we studied the developmental dynamics and their underlying juvenile hormone OH) titers in a wood-dwelling termite. Cryptotermes secundus, which is characterized by an ancestral life style of living in dead wood and individuals being totipotent in development. The following general pattern elements could be identified during winged sexual development (i) regressive molts were accompanied by longer intermolt periods than other molting types, (ii) JH titers decreased gradually during the developmental transition from larva (immatures without wing buds), to nymph (immatures with wing buds), to winged adult, (iii) in all nymphal stages, the JH titer rose before the next molt and dropped thereafter within the first week, (iv) considerable variation in JH titers occurred in the midphase of the molting cycle of the 2nd and 3rd nymphal instar, inferring that this variation may reflect the underlying endocrine signature of each of the three molting types, (v) the 4th nymphal instar, the shortest of all, seems to be a switch point in development, as nymphs in this stage mainly developed progressively. When comparing these patterns with endocrine signatures seen in cockroaches, the developmental program of Cryprotermes can be interpreted as a co-option and repetitive use of hormonal dynamics of the post dorsal-closure phase of cockroach embryonic development. (C) 2012 Elsevier Ltd. All tights reserved.