Circulating perturbation of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is associated to cardiac remodeling and NLRP3 inflammasome in cardiovascular patients with insulin resistance risk.

Lipidome perturbation occurring during meta-inflammation is associated to left ventricle (LV) remodeling though the activation of the NLRP3 inflammasome, a key regulator of chronic inflammation in obesity-related disorders. Little is known about phosphatidylcholine (PC) and phosphatidylethanolamine (PE) as DAMP-induced NLRP3 inflammasome. Our study is aimed to evaluate if a systemic reduction of PC/PE molar ratio can affect NLRP3 plasma levels in cardiovascular disease (CVD) patients with insulin resistance (IR) risk. Forty patients from IRCCS Policlinico San Donato were enrolled, and their blood samples were drawn before heart surgery. LV geometry measurements were evaluated by echocardiography and clinical data associated to IR risk were collected. PC and PE were quantified by ESI-MS/MS. Circulating NLRP3 was quantified by an ELISA assay. Our results have shown that CVD patients with IR risk presented systemic lipid impairment of PC and PE species and their ratio in plasma was inversely associated to NLRP3 levels. Interestingly, CVD patients with IR risk presented LV changes directly associated to increased levels of NLRP3 and a decrease in PC/PE ratio in plasma, highlighting the systemic effect of meta-inflammation in cardiac response. In summary, PC and PE can be considered bioactive mediators associated to both the NLRP3 and LV changes in CVD patients with IR risk.

Human epicardial adipose tissue expresses glucose-dependent insulinotropic polypeptide, glucagon, and glucagon-like peptide-1 receptors as potential targets of pleiotropic therapies.

AIMS: Human epicardial adipose tissue (EAT) plays a crucial role in the development and progression of coronary artery disease, atrial fibrillation, and heart failure. Microscopically, EAT is composed of adipocytes, nerve tissues, inflammatory, stromovascular, and immune cells. Epicardial adipose tissue is a white adipose tissue, albeit it also has brown fat-like or beige fat-like features. No muscle fascia divides EAT and myocardium; this allows a direct interaction and crosstalk between the epicardial fat and the myocardium. Thus, it might be a therapeutic target for pharmaceutical compounds acting on G-protein-coupled receptors, such as those for glucose-dependent insulinotropic polypeptide (GIP), glucagon (GCG), and glucagon-like peptide-1 (GLP-1), whose selective stimulation with innovative drugs has demonstrated beneficial cardiovascular effects. The precise mechanism of these novel drugs and their tissue and cellular target(s) need to be better understood. We evaluate whether human EAT expresses GIP, GCG, and GLP-1 receptors and whether their presence is related to EAT transcriptome. We also investigated protein expression and cell-type localization specifically for GIP receptor (GIPR) and glucagon receptor (GCGR). METHODS AND RESULTS: Epicardial adipose tissue samples were collected from 33 patients affected by cardiovascular diseases undergoing open heart surgery (90.9% males, age 67.2 ± 10.5 years mean ± SD). Microarray and immunohistochemistry analyses were performed. Microarray analysis showed that GIPR and GCGR messenger ribonucleic acids (mRNAs) are expressed in EAT, beyond confirming the previously found GLP-1 [3776 ± 1377 arbitrary unit (A.U.), 17.77 ± 14.91 A.U., and 3.41 ± 2.27 A.U., respectively]. The immunohistochemical analysis consistently indicates that GIPR and GCGR are expressed in EAT, mainly in macrophages, isolated, and in crown-like structures. In contrast, only some mature adipocytes of different sizes showed cytoplasmic immunostaining, similar to endothelial cells and pericytes in the capillaries and pre-capillary vascular structures. Notably, EAT GIPR is statistically associated with the low expression of genes involved in free fatty acid (FFA) oxidation and transport and those promoting FFA biosynthesis and adipogenesis (P < 0.01). Epicardial adipose tissue GCGR, in turn, is related to genes involved in FFA transport, mitochondrial fatty acid oxidation, and white-to-brown adipocyte differentiation, in addition to genes involved in the reduction of fatty acid biosynthesis and adipogenesis (P < 0.01). CONCLUSIONS: Having reported the expression of the GLP-1 receptor previously, here, we showed that GIPR and GCGR similarly present at mRNA and protein levels in human EAT, particularly in macrophages and partially adipocytes, suggesting these G-protein-coupled receptors as pharmacological targets on the ongoing innovative drugs, which seem cardiometabolically healthy well beyond their effects on glucose and body weight.

Human epicardial adipose tissue (EAT) is a unique and multifunctional fat compartment of the heart. Microscopically, EAT is composed of adipocytes, nerve tissues, inflammatory, stromovascular, and immune cells. Epicardial adipose tissue is a white adipose tissue, albeit it also has brown fat-like or beige fat-like features. No muscle fascia divides EAT and myocardium; this allows a direct interaction and crosstalk between the epicardial fat and the myocardium. Due to its distinctive transcriptome and functional proximity to the heart, EAT can play a key role in the development and progression of coronary artery disease, atrial fibrillation, and heart failure. Clinically, EAT, given its rapid metabolism and simple measurability, can be considered a novel therapeutic target, owing to its responsiveness to drugs with pleiotropic and clear beneficial cardiovascular effects such as the glucagon-like peptide-1 receptor (GLP-1R) agonists.Human EAT is found to express the genes encoding the receptors of glucose-dependent insulinotropic polypeptide receptor (GIPR), glucagon receptor (GCGR), and GLP-1. The immunohistochemistry indicates that GIP and GCG receptor proteins are present in EAT samples. Epicardial adipose tissue GIPR is inversely associated with genes involved in free fatty acid (FFA) oxidation and transport and with genes promoting FFA biosynthesis and adipogenesis. Epicardial adipose tissue GCGR is correlated with genes promoting FFA transport and activation for mitochondrial beta-oxidation and white-to-brown adipocyte differentiation and with genes reducing FFA biosynthesis and adipogenesis.As the myocardium relies mostly on FFAs as fuel and is in direct contiguity with EAT, these findings may have a great importance for the modulation of the myocardial activity and performance. Given the emerging use and cardiovascular effects of GLP-1R agonists, dual GIPR/GLP-1R agonists, and GLP-1R/GIPR/GCGR triagonists, we believe that pharmacologically targeting and potentially modulating organ-specific fat depots through G-protein­coupled receptors may produce beneficial cardiovascular and metabolic effects.

In Patients with Chronic Kidney Disease Advanced Glycation End-Products Receptors Isoforms (sRAGE and esRAGE) Are Associated with Malnutrition.

BACKGROUND: in patients with chronic kidney disease (CKD), the inflammatory and pro-oxidant milieu may contribute to malnutrition development. In this study, we investigated the relationship between inflammation, advanced glycation end-products (AGEs), and their receptors (RAGEs) with malnutrition in CKD patients. METHODS: we evaluated 117 patients. AGEs were quantified by fluorescence intensity using a fluorescence spectrophotometer, soluble RAGEs isoforms, and inflammatory interleukins by ELISA. Malnutrition was assessed by a malnutrition inflammation score. RESULTS: mean age was 80 ± +11 years, eGFR was 25 ± +11 mL/min/1.73 m2 and BMI was 28 ± 5 Kg/m2. Malnourished individuals were older, had lower estimated protein intake (nPCR 0.65 ± 0.2 vs. 0.8 ± 0.2 vs. 0.8 ± 0.3, p = 0.01), higher C reactive protein (CRP 0.6 ± 1 vs. 0.6 ± 0.7 vs. 0.17 ± 0.13, p = 0.02) and tumor necrosis factor α (TNF α 14.7 ± 8.7 vs. 15.6 ± 8 vs. 11.8 ± 5.8, p = 0.029). Malnourished patients had higher sRAGE (2813 ± 1477 vs. 2158 ± 1236 vs. 2314 ± 1115, p = 0.035) and esRAGE (648 [408-1049] vs. 476 [355-680] vs. 545 [380-730] p = 0.033). In the multivariate analysis, only sRAGE maintained its association with malnutrition (p = 0.02) independently of aging and inflammation. CONCLUSIONS: in CKD patients, RAGEs isoforms, but not AGEs, are associated with malnutrition, irrespective of systemic inflammation, aging, and renal function.

A Wide-Proteome Analysis to Identify Molecular Pathways Involved in Kidney Response to High-Fat Diet in Mice.

The etiopathogenesis of obesity-related chronic kidney disease (CKD) is still scarcely understood. To this aim, we assessed the effect of high-fat diet (HF) on molecular pathways leading to organ damage, steatosis, and fibrosis. Six-week-old male C57BL/6N mice were fed HF diet or normal chow for 20 weeks. Kidneys were collected for genomic, proteomic, histological studies, and lipid quantification. The main findings were as follows: (1) HF diet activated specific pathways leading to fibrosis and increased fatty acid metabolism; (2) HF diet promoted a metabolic shift of lipid metabolism from peroxisomes to mitochondria; (3) no signs of lipid accumulation and/or fibrosis were observed, histologically; (4) the early signs of kidney damage seemed to be related to changes in membrane protein expression; (5) the proto-oncogene MYC was one of the upstream transcriptional regulators of changes occurring in protein expression. These results demonstrated the potential usefulness of specific selected molecules as early markers of renal injury in HF, while histomorphological changes become visible later in obesity-related CDK. The integration of these information with data from biological fluids could help the identification of biomarkers useful for the early detection and prevention of tissue damage in clinical practice.

Effect of Denosumab on Glucose Homeostasis in Postmenopausal Women with Breast Cancer Treated with Aromatase Inhibitors: A Pilot Study.

BACKGROUND: Aromatase inhibitors in women with breast cancer have been associated with cancer treatment-induced bone loss (CTIBL), increased fracture risk, and impairment of glucose metabolism. Denosumab (Dmab), a monoclonal antibody against RANKL, which is a key regulator of the osteoclast activity, is effective as an antiresorptive agent in the treatment of CTIBL. Since RANKL/RANK pathway may contribute to the pathogenesis of glucometabolic disorders, it has been suggested that Dmab may improve glucose homeostasis. Our pilot study evaluated the effect of a single administration of 60 mg Dmab on glucose metabolism in a cohort of women with breast cancer treated with aromatase inhibitors. METHODS: Fifteen postmenopausal nondiabetic women were prospectively enrolled. Oral glucose tolerance test (OGTT) and metabolic parameters, including FGF21, were assessed at baseline and one month after Dmab injection. Midterm glucose control was evaluated by measuring glycated haemoglobin (HbA1c) levels 5 months after Dmab. RESULTS: Parameters of glucose metabolism were not different one month after Dmab but circulating FGF21 levels significantly decreased (128.5 ± 46.8 versus 100.2 ± 48.8 pg/mL; p=0.016). Considering patients with insulin resistance at baseline (HOMA-IR > 2.5 and Matsuda Index < 2.5; n = 5), reduced mean fasting insulin levels (16.3 ± 4.9 versus 13.5 ± 3.5 mcU/mL; p=0.029) and increased insulin sensitivity index QUICKI (0.317 ± 0.013 versus 0.327 ± 0.009; p=0.025) were found. Nonetheless, HbA1c increased 5 months after Dmab (36.0 ± 2.3 versus 39.6 ± 3.1 mmol/mol; p=0.01). CONCLUSIONS: Although RANKL blockade induced a short-term positive effect on insulin sensitivity, particularly in insulin-resistant patients, a benefit on long-term glucose metabolism was not evident. In conclusion, Dmab is safe for glucose metabolism in aromatase inhibitor-treated women with breast cancer.

PCSK9 Expression in Epicardial Adipose Tissue: Molecular Association with Local Tissue Inflammation.

Epicardial adipose tissue (EAT) has the unique property to release mediators that nourish the heart in healthy conditions, an effect that becomes detrimental when volume expands and proinflammatory cytokines start to be produced. Proprotein convertase subtilisin/kexin type 9 (PCSK9), a proinflammatory mediator involved in atherosclerosis, is also produced by visceral fat. Due to the correlation of inflammation with PCSK9 and EAT enlargement, we evaluated whether PCSK9 was expressed in EAT and associated with EAT inflammation and volume. EAT samples were isolated during surgery. EAT thickness was measured by echocardiography. A microarray was used to explore EAT transcriptoma. The PCSK9 protein levels were measured by Western Blot in EAT and ELISA in plasma. PCSK9 was expressed at both the gene and protein levels in EAT. We found a positive association with EAT thickness and local proinflammatory mediators, in particular, chemokines for monocytes and lymphocytes. No association was found with the circulating PCSK9 level. The expression of PCSK9 in EAT argues that PCSK9 is part of the EAT secretome and EAT inflammation is associated with local PCSK9 expression, regardless of circulating PCSK9 levels. Whether reducing EAT inflammation or PCSK9 local levels may have beneficial effects on EAT metabolism and cardiovascular risk needs further investigations.

ST2/IL-33 signaling in cardiac fibrosis.

Cardiac fibrosis is a significant global health problem associated with nearly all forms of heart disease. In the heart interstitial fibrosis may be reparative, replacing areas damaged by myocyte loss after acute infarction, or compensative, responding to cardiac overload. However, after injury in chronic cases activated myofibroblasts contribute to the tissue imbalance of the newer molecules associated with cardiac fibrosis, interleukin (IL-33), and suppression of tumorigenicity 2 (ST2). Physiological stretching causes myofibroblasts to release IL-33 which binds the ST2 receptor (ST2L) on the cardiomyocyte membrane, promoting cell survival and integrity. But in chronic conditions, local and neighboring cells can increase the release of IL-33's decoy, soluble ST2 (sST2), which blocks IL-33/ST2L binding, promoting tissue fibrosis. We review recent studies that have illustrated novel aspects of ST2/IL-33 signaling mediating cardiac fibrosis, and some newer biomolecular targets for the prevention and treatment of maladaptive remodeling.

Correlational study on altered epicardial adipose tissue as a stratification risk factor for valve disease progression through IL-13 signaling.

AIMS: Genetic and environmental factors all interact in the risk of progression of valvular dysfunctions. Previous studies reported a relation between valve diseases and epicardial adipose tissue (EAT) thickness. The aim of this study was to verify the possible relationship between the molecular pattern of EAT related to IL-13 fibrogenic cytokine expression and valve dysfunction. METHODS AND RESULTS: A valvular heart disease (VHD) population was stratified according to their median EAT thickness (7 mm). The molecular expression of IL-13 in EAT is directly related to the molecular expression of genes associated with extracellular matrix (ECM) turnover, macrophage infiltration and promotion of the formation of ectopic calcific nodules involved in aorta coarctation and calcification. CONCLUSION: IL-13 gene expression in altered EAT is directly related to the expression of genes involved in ECM turnover and the formation of ectopic calcific nodules, suggesting measurements of EAT as a stratification risk factor for valve instability in the VHD patients.

Expression of the Receptor for Advanced Glycation End Products in Epicardial Fat: Link with Tissue Thickness and Local Insulin Resistance in Coronary Artery Disease.

Increased expression of receptor for advanced glycation end products (RAGE) in adipose tissue has been associated with inflammation, adipocyte hypertrophy, and impaired insulin signal. Epicardial adipose tissue (EAT), a visceral fat surrounding the myocardium, is potentially involved in the onset/progression of coronary artery disease (CAD). To date, the role of RAGE in EAT has not been explored much. We examined whether the RAGE expression in EAT was associated with EAT adiposity and metabolic dysfunctions normally found in CAD patients. EAT samples were obtained from 33 patients undergoing open-heart surgery. EAT expression of RAGE, GLUT4, adiponenctin, GLO1, HMGB1, TLR-4, and MyD88 was analyzed by microarray. EAT thickness was quantified by echocardiography. Anthropometric measures and clinical parameters were taken. BMI, HOMA-IR, and LAP indices were calculated. With increasing RAGE expression in EAT we observed increases in EAT thickness, reduced expression of GLUT4, adiponectin, and GLO1, and elevations of HMGB1, TLR-4, and MyD88. There were significant correlations between RAGE and EAT thickness and between RAGE and the genes. LAP was higher in patients with increased RAGE expression. Our data suggest that in CAD patients RAGE may be involved in promoting EAT adiposity and metabolic dysfunction, such as impaired insulin signaling.

Adipokines, hormonal parameters, and cardiovascular risk factors: similarities and differences between patients with erectile dysfunction of arteriogenic and nonarteriogenic origin.

INTRODUCTION: Erectile dysfunction (ED) is often associated with metabolic disorders. Leptin and adiponectin are adipose tissue-derived hormones involved in the regulation of metabolic homeostasis and considered important players in the relationship among obesity and cardiovascular diseases. AIM: Leptin, adiponectin, leptin to adiponectin ratio (L/A), and their correlation with hormonal and metabolic parameters were examined in male with arteriogenic- (A-ED) and nonarteriogenic-ED (NA-ED). MAIN OUTCOME MEASURES: Biochemical, metabolic, and hormonal parameters of men with A-ED were compared with those of male with NA-ED. METHODS: Diagnosis of ED was based on the International Index of Erectile Function Score. Its etiology was classified with penile echo-color Doppler at baseline and after intracavernous injection of prostaglandin E1. Leptin and adiponectin were measured by enzyme-linked immunosorbent assay. RESULTS: In A-ED subjects, increased levels of insulin, glycated hemoglobin, homeostasis model assessment of insulin resistance (HOMA-IR) index, body mass index (BMI), leptin, and L/A and decreased levels of total, free, and bioavailable testosterone were observed compared with NA-ED subjects. A trend toward lower estradiol level was also present in A-ED patients, even if not statistically significant. Reduced levels of adiponectin have been observed in both groups compared with patients without ED. Leptin and L/A correlated similarly with several parameters (negatively with testosterone/estradiol ratio and positively with BMI, insulin, HOMA-IR, and 17-beta estradiol). L/A resulted further correlated negatively with high-density lipoprotein and positively with triglycerides. CONCLUSIONS: Not all ED cases are similar. In fact, A-ED patients display a more complicated metabolic status characterized by overweight and obesity and associated to sexual hormone alteration. Whether changes in body composition and modulation of adipokine levels can improve local endothelial function need further investigation.

Natural zeolites chabazite/phillipsite/analcime increase blood levels of antioxidant enzymes.

Imbalance between reactive oxygen species generation and antioxidant capacity induces a condition known as oxidative stress which is implicated in numerous pathological processes. In this study we evaluated whether natural zeolites chabazite/phillipsite/analcime may affect the levels of different antioxidant enzymes (gluthatione peroxidase, superoxide dismutase, gluthatione reductase), total antioxidant status and oxidative stress in 25 clinically healthy men, both non-smokers and smokers. Measurements were performed on whole blood or on plasma samples before (T0) and after 4-weeks zeolites intake (T1). At T1, gluthatione peroxidase, superoxide dismutase and gluthatione reductase increased compared to T0 levels, both considering all subjects as joint and after subdivision in non-smokers and smokers. Differently, a reduction in total antioxidant status was observed at T1. Anyway, total antioxidant status resulted higher than the reference values in both groups at each time point. A decrease in lipid peroxidation, a major indicator of oxidative stress assessed by monitoring thiobarbituric acid reactive substances, was also observed in all subjects at T1. Our results suggested that chabazite/phillipsite/analcime may help to counteract oxidative stress in apparently healthy subjects exposed to different oxidative stress risk factors, such as smoking, thus representing a particular kind of food with potential antioxidant properties.

Parthenolide inhibits the LPS-induced secretion of IL-6 and TNF-α and NF-κB nuclear translocation in BV-2 microglia.

Feverfew (Tanacetum parthenium [L.] Sch. Bip. [Asteraceae]) is a popular herbal treatment used to prevent and treat headache and migraine. Parthenolide (PTN), the sesquiterpene lactonic derivative that is the plant's major component, might be one of the ingredients that act on mediators of inflammation. In the present study, in cultured lipopolysaccharide (LPS)-stimulated BV-2 microglia pretreatment with PTN caused a dose-dependent reduction of interleukin-6 (IL-6) secretion (29% by 200 nm, p < 0.001; 45% by 1 µm, p < 0.001; 98% by 5 µm, p < 0.001); at 5 µm, the highest concentration tested, it also reduced the secretion of TNF-α (54%, p < 0.001). Western blotting analysis on separate cytoplasmic and nuclear extracts showed that PTN strongly reduced the translocation of nuclear factor (NF)-κB to the cell nucleus. The reduction of microglial activation by inhibition of proinflammatory agents may help attenuate the onset and intensity of acute migraine attacks. These in vitro results provide an additional explanation for the efficacy of orally administered T. parthenium as an antimigraine agent.

VEGF signalling controls GnRH neuron survival via NRP1 independently of KDR and blood vessels.

Gonadotropin-releasing hormone (GnRH) neurons are neuroendocrine cells that are born in the nasal placode during embryonic development and migrate through the nose and forebrain to the hypothalamus, where they regulate reproduction. Many molecular pathways that guide their migration have been identified, but little is known about the factors that control the survival of the migrating GnRH neurons as they negotiate different environments. We previously reported that the class 3 semaphorin SEMA3A signals through its neuropilin receptors, NRP1 and NRP2, to organise the axons that guide migrating GnRH neurons from their birthplace into the brain. By combining analysis of genetically altered mice with in vitro models, we show here that the alternative neuropilin ligand VEGF164 promotes the survival of migrating GnRH neurons by co-activating the ERK and AKT signalling pathways through NRP1. We also demonstrate that survival signalling relies on neuronal, but not endothelial, NRP1 expression and that it occurs independently of KDR, the main VEGF receptor in blood vessels. Therefore, VEGF164 provides survival signals directly to developing GnRH neurons, independently of its role in blood vessels. Finally, we show that the VEGF164-mediated neuronal survival and SEMA3A-mediated axon guidance cooperate to ensure that migrating GnRH neurons reach the brain. Thus, the loss of both neuropilin ligands leads to an almost complete failure to establish the GnRH neuron system.

The natural antioxidant alpha-lipoic acid induces p27(Kip1)-dependent cell cycle arrest and apoptosis in MCF-7 human breast cancer cells.

Unlike normal cells, tumor cells survive in a specific redox environment where the elevated reactive oxygen species contribute to enhance cell proliferation and to suppress apoptosis. Alpha-lipoic acid, a naturally occurring reactive oxygen species scavenger, has been shown to possess anticancer activity, due to its ability to suppress proliferation and to induce apoptosis in different cancer cell lines. Since at the moment little information is available regarding the potential effects of alpha-lipoic acid on breast cancer, in the present study we addressed the question whether alpha-lipoic acid induces cell cycle arrest and apoptosis in the human breast cancer cell line MCF-7. Moreover, we investigated some molecular mechanisms which mediate alpha-lipoic acid actions, focusing on the role of the PI3-K/Akt signalling pathway. We observed that alpha-lipoic acid is able to scavenge reactive oxygen species in MCF-7 cells and that the reduction of reactive oxygen species is followed by cell growth arrest in the G1 phase of the cell cycle, via the specific inhibition of Akt pathway and the up-regulation of the cyclin-dependent kinase inhibitor p27(kip1), and by apoptosis, via changes of the ratio of the apoptotic-related protein Bax/Bcl-2. Thus, the anti-tumor activity of alpha-lipoic acid observed in MCF-7 cells further stresses the role of redox state in regulating cancer initiation and progression.

Regulation of prostate cancer cell proliferation by somatostatin receptor activation.

Although some evidence supports the antitumoral effects of somatostatin (SRIF) and related agonists, the available data in prostate cancer (PCa) model systems and clinical studies are few, conflicting and not conclusive. This study investigated the effects of lanreotide and new mono- and bi-specific SRIF agonists on proliferation, ligand-driven SRIF receptor (sst) dimerization and secretory pattern of the IGF system in LNCaP cells, a model of androgen-dependent PCa. LNCaP expressed all sst(s), but sst(4). Among them, sst(1) and sst(3) were inversely regulated by serum concentration. sst(1)/sst(2) and sst(2)/sst(5) dimers were constitutively present and further stabilized by treatment with BIM-23704 (sst(1)/sst(2)) and BIM-23244 (sst(2)/sst(5)), respectively. Dose-response studies showed that lanreotide and BIM-23244 were significantly more potent in inhibiting LNCaP cell proliferation than BIM-23120 (sst(2)) and BIM-23206 (sst(5)) alone or in combination. Treatment with BIM-23926 [corrected] (sst(1)) markedly reduced cell proliferation, whereas exposure to BIM-23704 resulted in a lower cell growth inhibition. The antiproliferative effects of BIM-23244, lanreotide and BIM-23704 were unchanged, reduced and abolished by the sst(2) antagonist BIM-23627, respectively. All SRIF analogs caused a significant induction in p27(KipI) and p21 and down-regulation of protein expression of cyclin E, as well as reduced IGF-I and IGF-II secretion. In particular, the administration of exogenous IGF-I, at variance to IGF-II, counteracted the inhibitory effect on cell proliferation of these compounds. Moreover, SRIF agonists reduced endogenous IGFBP-3 proteolysis. These results show that, in LNCaP cells, activation of sst(1) and sst(2)/sst(5) results in relevant antiproliferative/antisecretive actions.

Cholinergic regulation of neuropeptide Y synthesis and release in human neuroblastoma cells.

The biosynthesis and release of neuropeptide Y (NPY) is regulated by several factors. Here, the effect of the muscarinic agonist carbachol on NPY biosynthesis and release was analyzed utilizing the SH-SY5Y human neuroblastoma cell line. We observed that: (a) carbachol moderately increased the post-translational cleavage of proNPY to NPY; (b) carbachol treatment stimulated NPY accumulation into the medium in a time- and dose-related manner; (c) protein kinase C activation is involved in carbachol-mediated NPY synthesis/release (>6h). In conclusion, the present observations support the hypothesis that muscarinic receptor activation regulates the biosynthesis and secretion of NPY.

Modulatory actions of neuropeptide Y on prostate cancer growth: role of MAP kinase/ERK 1/2 activation.

Neuroendocrine molecules play a significant role in the progression of human prostate cancer (PCa) and its neuroendocrine differentiation has been associated to a worse prognosis. Evidence exists that, among these molecules, the pleiotropic neuropeptide Y (NPY) and the related receptors may play a role in the normal prostate as well as in the progression of human PCa, which represents one of the most common malignant diseases among men in the Western world. The role of NPY in PCa biology appears to vary in different in vitro human PCa cell systems, since it has been found to reduce the proliferation of LNCaP and DU145 cells, but to stimulate the growth of PC3 cells. These effects are mediated mainly by the NPY Y1 receptor and are associated with a clone-specific pattern of intracellular signaling activation, including a peculiar time-course of MAPK/ERK1/2 phosphorylation (long-lasting in DU145 and transient in PC3 cells). In conclusion, several studies support the concept that NPY and the related receptors are overexpressed in PCa and may play a relevant role in PCa progression. The diagnostic and therapeutical value of targeting the NPY system in PCa will be evaluated in future studies.

Leukemia inhibitory factor induces the chemomigration of immortalized gonadotropin-releasing hormone neurons through the independent activation of the Janus kinase/signal transducer and activator of transcription 3, mitogen-activated protein kinase/extracellularly regulated kinase 1/2, and phosphatidylinositol 3-kinase/Akt signaling pathways.

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine of the IL-6 superfamily. LIF acts through a cell-surface receptor complex formed by two subunits, the specific LIF receptor beta (LIFRbeta) and the glycoprotein 130. Little is known about LIF involvement in modulating the neuroendocrine circuitry governing the reproductive function and, specifically, the development of GnRH-secreting neurons. In the present study, we evaluated the effect of LIF on the in vitro migration of GN11 cells, a model of immature and migratory GnRH neurons, and the signaling pathways involved in this process. GN11 cells expressed both LIFRbeta and glycoprotein 130 subunits. Exposure of GN11 cells to 100 ng/ml LIF resulted in activation of the Janus kinases (Jaks)/signal transducer and activator of transcription 3, MAPK/ERK1/2, and phosphatidylinositol 3-kinase/protein kinase B/Akt pathways. The selective inhibition of Jaks, MAPK kinase, and phosphatidylinositol 3-kinase indicated that these signaling pathways were activated independently by LIF and that Jak2 is not the main kinase involved in LIF signaling. Exposure of GN11 cells to LIF for 3 h induced a concentration-dependent chemotactic response, with a plateau at 100 ng/ml LIF. LIF was also found to induce chemokinesis of GN11 cells. Furthermore, LIF-promoted GN11 migration was the result of the partial and independent contribution of all the three signaling pathways activated by LIF. The present data, together with the observation that LIF and LIFRbeta are expressed prenatally in the mouse nasal compartment, would suggest that LIF might participate in the migration of GnRH neurons.

Role of neuropeptide Y and its receptors in the progression of endocrine-related cancer.

The neuropeptide Y (NPY) family of peptides, in addition to its many physiological actions, has also been involved in the modulation of tumor progression, with specific reference to endocrine-related cancers such as neuroendocrine tumors, breast and prostate cancers. These have been found either to express NPY receptors, or to secrete NPY-related peptides, or both. The study of the role of the NPY family of peptides in the biology of endocrine-related tumors, specifically concerning cell proliferation, angiogenesis, invasion and metastatization, may help to clarify some aspects of tumor pathophysiology, as well as to indicate novel diagnostic markers and therapeutical approaches.

Activation of the Y1 receptor by neuropeptide Y regulates the growth of prostate cancer cells.

This study deals with the role of neuropeptide Y (NPY) in the regulation of cell proliferation. NPY is expressed in the normal and tumoral prostate, but no data on its possible role in prostate cancer (PCa) progression are available. Therefore, we evaluated the direct effect of NPY on the growth of the human PCa cell lines LNCaP (androgen dependent) and DU145 and PC3 (androgen independent). All PCa cell lines expressed Y1-R gene and protein. NPY treatment reduced the proliferation of LNCaP and DU145 cells and increased that of PC3 cells. The Y1-R antagonist BIBP3226 abolished such effects, suggesting a mandatory role of Y1-R in this process. LNCaP cells showed elevated constitutive levels of phosphorylated ERK1/2, which were not affected by NPY. In DU145 cells, NPY stimulated a long-lasting ERK1/2 activation, whereas, in PC3 cells, this effect was rapid and transient and required activation of protein kinase C. Moreover, in both cell lines, pretreatment with BIBP3226 prevented the NPY-induced ERK1/2 phosphorylation, further supporting Y1-R involvement. NPY treatment reduced forskolin-stimulated cAMP accumulation only in PC3 cells and did not change intracellular calcium concentration in any PCa cell line. These data indicate that NPY may directly regulate PCa cell growth via Y1-R. The direction of this effect appears to be related to the time kinetics of MAPK activation, i.e. long-lasting vs. transient, and to the clone-specific involvement of other intracellular signals. These findings suggest that NPY-related mechanisms might play a relevant role in the progression of PCa, at both androgen dependent and independent stages.